Commit Graph

596 Commits

Author SHA1 Message Date
Geert Uytterhoeven
22293c3373 dma-mapping: save base/size instead of pointer to shared DMA pool
On RZ/Five, which is non-coherent, and uses CONFIG_DMA_GLOBAL_POOL=y:

    Oops - store (or AMO) access fault [#1]
    CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc1-00015-g8a6e02d0c00e #201
    Hardware name: Renesas SMARC EVK based on r9a07g043f01 (DT)
    epc : __memset+0x60/0x100
     ra : __dma_alloc_from_coherent+0x150/0x17a
    epc : ffffffff8062d2bc ra : ffffffff80053a94 sp : ffffffc60000ba20
     gp : ffffffff812e9938 tp : ffffffd601920000 t0 : ffffffc6000d0000
     t1 : 0000000000000000 t2 : ffffffffe9600000 s0 : ffffffc60000baa0
     s1 : ffffffc6000d0000 a0 : ffffffc6000d0000 a1 : 0000000000000000
     a2 : 0000000000001000 a3 : ffffffc6000d1000 a4 : 0000000000000000
     a5 : 0000000000000000 a6 : ffffffd601adacc0 a7 : ffffffd601a841a8
     s2 : ffffffd6018573c0 s3 : 0000000000001000 s4 : ffffffd6019541e0
     s5 : 0000000200000022 s6 : ffffffd6018f8410 s7 : ffffffd6018573e8
     s8 : 0000000000000001 s9 : 0000000000000001 s10: 0000000000000010
     s11: 0000000000000000 t3 : 0000000000000000 t4 : ffffffffdefe62d1
     t5 : 000000001cd6a3a9 t6 : ffffffd601b2aad6
    status: 0000000200000120 badaddr: ffffffc6000d0000 cause: 0000000000000007
    [<ffffffff8062d2bc>] __memset+0x60/0x100
    [<ffffffff80053e1a>] dma_alloc_from_global_coherent+0x1c/0x28
    [<ffffffff80053056>] dma_direct_alloc+0x98/0x112
    [<ffffffff8005238c>] dma_alloc_attrs+0x78/0x86
    [<ffffffff8035fdb4>] rz_dmac_probe+0x3f6/0x50a
    [<ffffffff803a0694>] platform_probe+0x4c/0x8a

If CONFIG_DMA_GLOBAL_POOL=y, the reserved_mem structure passed to
rmem_dma_setup() is saved for later use, by saving the passed pointer.
However, when dma_init_reserved_memory() is called later, the pointer
has become stale, causing a crash.

E.g. in the RZ/Five case, the referenced memory now contains the
reserved_mem structure for the "mmode_resv0@30000" node (with base
0x30000 and size 0x10000), instead of the correct "pma_resv0@58000000"
node (with base 0x58000000 and size 0x8000000).

Fix this by saving the needed reserved_mem structure's contents instead.

Fixes: 8a6e02d0c0 ("of: reserved_mem: Restructure how the reserved memory regions are processed")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-11-14 10:45:09 +01:00
Sean Anderson
d5bbfbad58 dma-mapping: fix swapped dir/flags arguments to trace_dma_alloc_sgt_err
trace_dma_alloc_sgt_err was called with the dir and flags arguments
swapped. Fix this.

Fixes: 68b6dbf1f4 ("dma-mapping: trace more error paths")
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410302243.1wnTlPk3-lkp@intel.com/
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-11-08 14:56:39 +01:00
Sean Anderson
68b6dbf1f4 dma-mapping: trace more error paths
It can be surprising to the user if DMA functions are only traced on
success. On failure, it can be unclear what the source of the problem
is. Fix this by tracing all functions even when they fail. Cases where
we BUG/WARN are skipped, since those should be sufficiently noisy
already.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-10-29 08:54:06 +01:00
Sean Anderson
c4484ab86e dma-mapping: use trace_dma_alloc for dma_alloc* instead of using trace_dma_map
In some cases, we use trace_dma_map to trace dma_alloc* functions. This
generally follows dma_debug. However, this does not record all of the
relevant information for allocations, such as GFP flags. Create new
dma_alloc tracepoints for these functions. Note that while
dma_alloc_noncontiguous may allocate discontiguous pages (from the CPU's
point of view), the device will only see one contiguous mapping.
Therefore, we just need to trace dma_addr and size.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-10-29 08:54:03 +01:00
Sean Anderson
3afff779a7 dma-mapping: trace dma_alloc/free direction
In preparation for using these tracepoints in a few more places, trace
the DMA direction as well. For coherent allocations this is always
bidirectional.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-10-29 08:54:00 +01:00
Christoph Hellwig
150745b49a dma-debug: remove DMA_API_DEBUG_SG
The scatterlist validity checks are pretty simple and cheap, perform them
unconditionally.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-10-29 08:53:37 +01:00
Christoph Hellwig
9d4f645a1f dma-debug: store a phys_addr_t in struct dma_debug_entry
dma-debug goes to great length to split incoming physical addresses into
a PFN and offset to store them in struct dma_debug_entry, just to
recombine those for all meaningful uses.  Just store a phys_addr_t
instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-10-29 08:53:37 +01:00
Levi Yun
7543c3e3b9 dma-debug: fix a possible deadlock on radix_lock
radix_lock() shouldn't be held while holding dma_hash_entry[idx].lock
otherwise, there's a possible deadlock scenario when
dma debug API is called holding rq_lock():

CPU0                   CPU1                       CPU2
dma_free_attrs()
check_unmap()          add_dma_entry()            __schedule() //out
                                                  (A) rq_lock()
get_hash_bucket()
(A) dma_entry_hash
                                                  check_sync()
                       (A) radix_lock()           (W) dma_entry_hash
dma_entry_free()
(W) radix_lock()
                       // CPU2's one
                       (W) rq_lock()

CPU1 situation can happen when it extending radix tree and
it tries to wake up kswapd via wake_all_kswapd().

CPU2 situation can happen while perf_event_task_sched_out()
(i.e. dma sync operation is called while deleting perf_event using
 etm and etr tmc which are Arm Coresight hwtracing driver backends).

To remove this possible situation, call dma_entry_free() after
put_hash_bucket() in check_unmap().

Reported-by: Denis Nikitin <denik@chromium.org>
Closes: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/2WMS7BBSF5OZYB63VT44U5YWLFP5HL6U/#RWM6MLQX5ANBTEQ2PRM7OXCBGCE6NPWU
Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-10-29 08:51:25 +01:00
Leon Romanovsky
b348b6d17f dma-mapping: report unlimited DMA addressing in IOMMU DMA path
While using the IOMMU DMA path, the dma_addressing_limited() function
checks ops struct which doesn't exist in the IOMMU case. This causes
to the kernel panic while loading ADMGPU driver.

BUG: kernel NULL pointer dereference, address: 00000000000000a0
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 10 UID: 0 PID: 611 Comm: (udev-worker) Tainted: G                T  6.11.0-clang-07154-g726e2d0cf2bb #257
Tainted: [T]=RANDSTRUCT
Hardware name: ASUS System Product Name/ROG STRIX Z690-G GAMING WIFI, BIOS 3701 07/03/2024
RIP: 0010:dma_addressing_limited+0x53/0xa0
Code: 8b 93 48 02 00 00 48 39 d1 49 89 d6 4c 0f 42 f1 48 85 d2 4c 0f 44 f1 f6 83 fc 02 00 00 40 75 0a 48 89 df e8 1f 09 00 00 eb 24 <4c> 8b 1c 25 a0 00 00 00 4d 85 db 74 17 48 89 df 41 ba 8b 84 2d 55
RSP: 0018:ffffa8d2c12cf740 EFLAGS: 00010202
RAX: 00000000ffffffff RBX: ffff8948820220c8 RCX: 000000ffffffffff
RDX: 0000000000000000 RSI: ffffffffc124dc6d RDI: ffff8948820220c8
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff894883c3f040
R13: ffff89488dac8828 R14: 000000ffffffffff R15: ffff8948820220c8
FS:  00007fe6ba881900(0000) GS:ffff894fdf700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000a0 CR3: 0000000111984000 CR4: 0000000000f50ef0
PKRU: 55555554
Call Trace:
 <TASK>
 ? __die_body+0x65/0xc0
 ? page_fault_oops+0x3b9/0x450
 ? _prb_read_valid+0x212/0x390
 ? do_user_addr_fault+0x608/0x680
 ? exc_page_fault+0x4e/0xa0
 ? asm_exc_page_fault+0x26/0x30
 ? dma_addressing_limited+0x53/0xa0
 amdgpu_ttm_init+0x56/0x4b0 [amdgpu]
 gmc_v8_0_sw_init+0x561/0x670 [amdgpu]
 amdgpu_device_ip_init+0xf5/0x570 [amdgpu]
 amdgpu_device_init+0x1a57/0x1ea0 [amdgpu]
 ? _raw_spin_unlock_irqrestore+0x1a/0x40
 ? pci_conf1_read+0xc0/0xe0
 ? pci_bus_read_config_word+0x52/0xa0
 amdgpu_driver_load_kms+0x15/0xa0 [amdgpu]
 amdgpu_pci_probe+0x1b7/0x4c0 [amdgpu]
 pci_device_probe+0x1c5/0x260
 really_probe+0x130/0x470
 __driver_probe_device+0x77/0x150
 driver_probe_device+0x19/0x120
 __driver_attach+0xb1/0x1e0
 ? __cfi___driver_attach+0x10/0x10
 bus_for_each_dev+0x115/0x170
 bus_add_driver+0x192/0x2d0
 driver_register+0x5c/0xf0
 ? __cfi_init_module+0x10/0x10 [amdgpu]
 do_one_initcall+0x128/0x380
 ? idr_alloc_cyclic+0x139/0x1d0
 ? security_kernfs_init_security+0x42/0x140
 ? __kernfs_new_node+0x1be/0x250
 ? sysvec_apic_timer_interrupt+0xb6/0xc0
 ? asm_sysvec_apic_timer_interrupt+0x1a/0x20
 ? _raw_spin_unlock+0x11/0x30
 ? free_unref_page+0x283/0x650
 ? kfree+0x274/0x3a0
 ? kfree+0x274/0x3a0
 ? kfree+0x274/0x3a0
 ? load_module+0xf2e/0x1130
 ? __kmalloc_cache_noprof+0x12a/0x2e0
 do_init_module+0x7d/0x240
 __se_sys_init_module+0x19e/0x220
 do_syscall_64+0x8a/0x150
 ? __irq_exit_rcu+0x5e/0x100
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fe6bb5980ee
Code: 48 8b 0d 3d ed 12 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0a ed 12 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd462219d8 EFLAGS: 00000206 ORIG_RAX: 00000000000000af
RAX: ffffffffffffffda RBX: 0000556caf0d0670 RCX: 00007fe6bb5980ee
RDX: 0000556caf0d3080 RSI: 0000000002893458 RDI: 00007fe6b3400010
RBP: 0000000000020000 R08: 0000000000020010 R09: 0000000000000080
R10: c26073c166186e00 R11: 0000000000000206 R12: 0000556caf0d3430
R13: 0000556caf0d0670 R14: 0000556caf0d3080 R15: 0000556caf0ce700
 </TASK>
Modules linked in: amdgpu(+) i915(+) drm_suballoc_helper intel_gtt drm_exec drm_buddy iTCO_wdt i2c_algo_bit intel_pmc_bxt drm_display_helper iTCO_vendor_support gpu_sched drm_ttm_helper cec ttm amdxcp video backlight pinctrl_alderlake nct6775 hwmon_vid nct6775_core coretemp
CR2: 00000000000000a0
---[ end trace 0000000000000000 ]---
RIP: 0010:dma_addressing_limited+0x53/0xa0
Code: 8b 93 48 02 00 00 48 39 d1 49 89 d6 4c 0f 42 f1 48 85 d2 4c 0f 44 f1 f6 83 fc 02 00 00 40 75 0a 48 89 df e8 1f 09 00 00 eb 24 <4c> 8b 1c 25 a0 00 00 00 4d 85 db 74 17 48 89 df 41 ba 8b 84 2d 55
RSP: 0018:ffffa8d2c12cf740 EFLAGS: 00010202
RAX: 00000000ffffffff RBX: ffff8948820220c8 RCX: 000000ffffffffff
RDX: 0000000000000000 RSI: ffffffffc124dc6d RDI: ffff8948820220c8
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff894883c3f040
R13: ffff89488dac8828 R14: 000000ffffffffff R15: ffff8948820220c8
FS:  00007fe6ba881900(0000) GS:ffff894fdf700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000a0 CR3: 0000000111984000 CR4: 0000000000f50ef0
PKRU: 55555554

Fixes: b5c58b2fdc ("dma-mapping: direct calls for dma-iommu")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219292
Reported-by: Niklāvs Koļesņikovs <pinkflames.linux@gmail.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Niklāvs Koļesņikovs <pinkflames.linux@gmail.com>
2024-09-23 08:38:56 +02:00
Christoph Hellwig
bb0e391975 dma-mapping: fix vmap and mmap of noncontiougs allocations
Commit b5c58b2fdc ("dma-mapping: direct calls for dma-iommu") switched
to use direct calls to dma-iommu, but missed the dma_vmap_noncontiguous,
dma_vunmap_noncontiguous and dma_mmap_noncontiguous behavior keyed off the
presence of the alloc_noncontiguous method.

Fix this by removing the now unused alloc_noncontiguous and
free_noncontiguous methods and moving the vmapping and mmaping of the
noncontiguous allocations into the iommu code, as it is the only provider
of actually noncontiguous allocations.

Fixes: b5c58b2fdc ("dma-mapping: direct calls for dma-iommu")
Reported-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
Tested-by: Xi Ruoyao <xry111@xry111.site>
2024-09-22 18:47:51 +02:00
Christoph Hellwig
a5fb217f13 dma-mapping: reflow dma_supported
dma_supported has become too much spaghetti for my taste.  Reflow it to
remove the duplicate use_dma_iommu condition and make the main path more
obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
2024-09-12 16:28:00 +02:00
Leon Romanovsky
f45cfab28f dma-mapping: reliably inform about DMA support for IOMMU
If the DMA IOMMU path is going to be used, the appropriate check should
return that DMA is supported.

Fixes: b5c58b2fdc ("dma-mapping: direct calls for dma-iommu")
Closes: https://lore.kernel.org/all/181e06ff-35a3-434f-b505-672f430bd1cb@notapiano
Reported-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> #KernelCI
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-09-12 09:19:35 +02:00
Sean Anderson
038eb433dc dma-mapping: add tracing for dma-mapping API calls
When debugging drivers, it can often be useful to trace when memory gets
(un)mapped for DMA (and can be accessed by the device). Add some
tracepoints for this purpose.

Use u64 instead of phys_addr_t and dma_addr_t (and similarly %llx instead
of %pa) because libtraceevent can't handle typedefs in all cases.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-09-10 07:47:19 +03:00
Leon Romanovsky
19156263cb dma-mapping: use IOMMU DMA calls for common alloc/free page calls
Common alloca and free pages routines are called when IOMMU DMA is used,
and internally it calls to DMA ops structure which is not available for
default IOMMU. This patch adds necessary if checks to call IOMMU DMA.

It fixes the following crash:

 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000040
 Mem abort info:
   ESR = 0x0000000096000006
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x06: level 2 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=00000000d20bb000
 [0000000000000040] pgd=08000000d20c1003
 , p4d=08000000d20c1003
 , pud=08000000d20c2003, pmd=0000000000000000
 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
 Modules linked in: ipv6 hci_uart venus_core btqca
v4l2_mem2mem btrtl qcom_spmi_adc5 sbs_battery btbcm qcom_vadc_common
cros_ec_typec videobuf2_v4l2 leds_cros_ec cros_kbd_led_backlight
cros_ec_chardev videodev elan_i2c
videobuf2_common qcom_stats mc bluetooth coresight_stm stm_core
ecdh_generic ecc pwrseq_core panel_edp icc_bwmon ath10k_snoc ath10k_core
ath mac80211 phy_qcom_qmp_combo aux_bridge libarc4 coresight_replicator
coresight_etm4x coresight_tmc
coresight_funnel cfg80211 rfkill coresight qcom_wdt cbmem ramoops
reed_solomon pwm_bl coreboot_table backlight crct10dif_ce
 CPU: 7 UID: 0 PID: 70 Comm: kworker/u32:4 Not tainted 6.11.0-rc6-next-20240903-00003-gdfc6015d0711 #660
 Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT)
 Workqueue: events_unbound deferred_probe_work_func
 hub 2-1:1.0: 4 ports detected

 pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : dma_common_alloc_pages+0x54/0x1b4
 lr : dma_common_alloc_pages+0x4c/0x1b4
 sp : ffff8000807d3730
 x29: ffff8000807d3730 x28: ffff02a7d312f880 x27: 0000000000000001
 x26: 000000000000c000 x25: 0000000000000000 x24: 0000000000000001
 x23: ffff02a7d23b6898 x22: 0000000000006cc0 x21: 000000000000c000
 x20: ffff02a7858bf410 x19: fffffe0a60006000 x18: 0000000000000001
 x17: 00000000000000d5 x16: 1fffe054f0bcc261 x15: 0000000000000001
 x14: ffff02a7844dc680 x13: 0000000000100180 x12: dead000000000100
 x11: dead000000000122 x10: 00000000001001ff x9 : ffff02a87f7b7b00
 x8 : ffff02a87f7b7b00 x7 : ffff405977d6b000 x6 : ffff8000807d3310
 x5 : ffff02a87f6b6398 x4 : 0000000000000001 x3 : ffff405977d6b000
 x2 : ffff02a7844dc600 x1 : 0000000100000000 x0 : fffffe0a60006000
 Call trace:
  dma_common_alloc_pages+0x54/0x1b4
  __dma_alloc_pages+0x68/0x90
  dma_alloc_pages+0x10/0x1c
  snd_dma_noncoherent_alloc+0x28/0x8c
  __snd_dma_alloc_pages+0x30/0x50
  snd_dma_alloc_dir_pages+0x40/0x80
  do_alloc_pages+0xb8/0x13c
  preallocate_pcm_pages+0x6c/0xf8
  preallocate_pages+0x160/0x1a4
  snd_pcm_set_managed_buffer_all+0x64/0xb0
  lpass_platform_pcm_new+0xc0/0xe8
  snd_soc_pcm_component_new+0x3c/0xc8
  soc_new_pcm+0x4fc/0x668
  snd_soc_bind_card+0xabc/0xbac
  snd_soc_register_card+0xf0/0x108
  devm_snd_soc_register_card+0x4c/0xa4
  sc7180_snd_platform_probe+0x180/0x224
  platform_probe+0x68/0xc0
  really_probe+0xbc/0x298
  __driver_probe_device+0x78/0x12c
  driver_probe_device+0x3c/0x15c
  __device_attach_driver+0xb8/0x134
  bus_for_each_drv+0x84/0xe0
  __device_attach+0x9c/0x188
  device_initial_probe+0x14/0x20
  bus_probe_device+0xac/0xb0
  deferred_probe_work_func+0x88/0xc0
  process_one_work+0x14c/0x28c
  worker_thread+0x2cc/0x3d4
  kthread+0x114/0x118
  ret_from_fork+0x10/0x20
 Code: f9411c19 940000c9 aa0003f3 b4000460 (f9402326)
 ---[ end trace 0000000000000000 ]---

Fixes: b5c58b2fdc ("dma-mapping: direct calls for dma-iommu")
Closes: https://lore.kernel.org/all/10431dfd-ce04-4e0f-973b-c78477303c18@notapiano
Reported-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> #KernelCI
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-09-05 14:29:42 +03:00
Chen Yu
f689a3ab7b dma-direct: optimize page freeing when it is not addressable
When the CMA allocation succeeds but isn't addressable, its buffer has
already been released and the page is set to NULL.  So later when the
normal page allocation succeeds but isn't addressable, __free_pages()
can be used to free that normal page rather than using
dma_free_contiguous that does extra checks that are not needed.

Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-09-04 07:08:51 +03:00
Christoph Hellwig
de6c85bf91 dma-mapping: clearly mark DMA ops as an architecture feature
DMA ops are a helper for architectures and not for drivers to override
the DMA implementation.

Unfortunately driver authors keep ignoring this.  Make the fact more
clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers
overriding their dma_ops depend on that.  These drivers should probably be
marked broken, but we can give them a bit of a grace period for that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> # for IPU6
Acked-by: Robin Murphy <robin.murphy@arm.com>
2024-09-04 07:08:51 +03:00
Leon Romanovsky
b5c58b2fdc dma-mapping: direct calls for dma-iommu
Directly call into dma-iommu just like we have been doing for dma-direct
for a while.  This avoids the indirect call overhead for IOMMU ops and
removes the need to have DMA ops entirely for many common configurations.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22 06:18:11 +02:00
Leon Romanovsky
f69e342eec dma-mapping: call ->unmap_page and ->unmap_sg unconditionally
Almost all instances of the dma_map_ops ->map_page()/map_sg() methods
implement ->unmap_page()/unmap_sg() too.  The once instance which doesn't
dma_dummy_ops which is used to fail the DMA mapping and thus there won't
be any calls to ->unmap_page()/unmap_sg().

Remove the checks for ->unmap_page()/unmap_sg() and call them directly to
create an interface that is symmetrical to ->map_page()/map_sg().

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22 06:18:11 +02:00
Catalin Marinas
ba0fb44aed dma-mapping: replace zone_dma_bits by zone_dma_limit
The hardware DMA limit might not be power of 2. When RAM range starts
above 0, say 4GB, DMA limit of 30 bits should end at 5GB.  A single high
bit can not encode this limit.

Use a plain  address for the DMA zone limit instead.

Since the DMA zone can now potentially span beyond 4GB physical limit of
DMA32, make sure to use DMA zone for GFP_DMA32 allocations in that case.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22 06:18:00 +02:00
Yosry Ahmed
fa3c109a6d dma-mapping: use bit masking to check VM_DMA_COHERENT
In dma_common_find_pages(), area->flags are compared directly with
VM_DMA_COHERENT. This works because VM_DMA_COHERENT is the only set
flag.

During development of a new feature (ASI [1]), a new VM flag is
introduced, and that flag can be injected into VM_DMA_COHERENT mappings
(among others).  The presence of that flag caused
dma_common_find_pages() to return NULL for VM_DMA_COHERENT addresses,
leading to a lot of problems ending in crashing during boot. It took a
bit of time to figure this problem out.

It was a mistake to inject a VM flag to begin with, but it took a
significant amount of debugging to figure out the problem. Most users of
area->flags use bitmasking rather than equivalency to check for flags.
Update dma_common_find_pages() and dma_common_free_remap() to do the
same, which would have avoided the boot crashing. Instead, add a warning
in dma_common_find_pages() if any extra VM flags are set to catch such
problems more easily during development.

No functional change intended.

[1]https://lore.kernel.org/lkml/20240712-asi-rfc-24-v1-0-144b319a40d8@google.com/

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-22 06:15:35 +02:00
Rik van Riel
bd44ca3de4 dma-debug: avoid deadlock between dma debug vs printk and netconsole
Currently the dma debugging code can end up indirectly calling printk
under the radix_lock. This happens when a radix tree node allocation
fails.

This is a problem because the printk code, when used together with
netconsole, can end up inside the dma debugging code while trying to
transmit a message over netcons.

This creates the possibility of either a circular deadlock on the same
CPU, with that CPU trying to grab the radix_lock twice, or an ABBA
deadlock between different CPUs, where one CPU grabs the console lock
first and then waits for the radix_lock, while the other CPU is holding
the radix_lock and is waiting for the console lock.

The trace captured by lockdep is of the ABBA variant.

-> #2 (&dma_entry_hash[i].lock){-.-.}-{2:2}:
                  _raw_spin_lock_irqsave+0x5a/0x90
                  debug_dma_map_page+0x79/0x180
                  dma_map_page_attrs+0x1d2/0x2f0
                  bnxt_start_xmit+0x8c6/0x1540
                  netpoll_start_xmit+0x13f/0x180
                  netpoll_send_skb+0x20d/0x320
                  netpoll_send_udp+0x453/0x4a0
                  write_ext_msg+0x1b9/0x460
                  console_flush_all+0x2ff/0x5a0
                  console_unlock+0x55/0x180
                  vprintk_emit+0x2e3/0x3c0
                  devkmsg_emit+0x5a/0x80
                  devkmsg_write+0xfd/0x180
                  do_iter_readv_writev+0x164/0x1b0
                  vfs_writev+0xf9/0x2b0
                  do_writev+0x6d/0x110
                  do_syscall_64+0x80/0x150
                  entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #0 (console_owner){-.-.}-{0:0}:
                  __lock_acquire+0x15d1/0x31a0
                  lock_acquire+0xe8/0x290
                  console_flush_all+0x2ea/0x5a0
                  console_unlock+0x55/0x180
                  vprintk_emit+0x2e3/0x3c0
                  _printk+0x59/0x80
                  warn_alloc+0x122/0x1b0
                  __alloc_pages_slowpath+0x1101/0x1120
                  __alloc_pages+0x1eb/0x2c0
                  alloc_slab_page+0x5f/0x150
                  new_slab+0x2dc/0x4e0
                  ___slab_alloc+0xdcb/0x1390
                  kmem_cache_alloc+0x23d/0x360
                  radix_tree_node_alloc+0x3c/0xf0
                  radix_tree_insert+0xf5/0x230
                  add_dma_entry+0xe9/0x360
                  dma_map_page_attrs+0x1d2/0x2f0
                  __bnxt_alloc_rx_frag+0x147/0x180
                  bnxt_alloc_rx_data+0x79/0x160
                  bnxt_rx_skb+0x29/0xc0
                  bnxt_rx_pkt+0xe22/0x1570
                  __bnxt_poll_work+0x101/0x390
                  bnxt_poll+0x7e/0x320
                  __napi_poll+0x29/0x160
                  net_rx_action+0x1e0/0x3e0
                  handle_softirqs+0x190/0x510
                  run_ksoftirqd+0x4e/0x90
                  smpboot_thread_fn+0x1a8/0x270
                  kthread+0x102/0x120
                  ret_from_fork+0x2f/0x40
                  ret_from_fork_asm+0x11/0x20

This bug is more likely than it seems, because when one CPU has run out
of memory, chances are the other has too.

The good news is, this bug is hidden behind the CONFIG_DMA_API_DEBUG, so
not many users are likely to trigger it.

Signed-off-by: Rik van Riel <riel@surriel.com>
Reported-by: Konstantin Ovsepian <ovs@meta.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-08-06 10:29:32 -07:00
Lance Richardson
28e8b7406d dma: fix call order in dmam_free_coherent
dmam_free_coherent() frees a DMA allocation, which makes the
freed vaddr available for reuse, then calls devres_destroy()
to remove and free the data structure used to track the DMA
allocation. Between the two calls, it is possible for a
concurrent task to make an allocation with the same vaddr
and add it to the devres list.

If this happens, there will be two entries in the devres list
with the same vaddr and devres_destroy() can free the wrong
entry, triggering the WARN_ON() in dmam_match.

Fix by destroying the devres entry before freeing the DMA
allocation.

Tested:
  kokonut //net/encryption
    http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03

Fixes: 9ac7849e35 ("devres: device resource management")
Signed-off-by: Lance Richardson <rlance@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-19 07:27:28 +02:00
Yang Li
b69bdba5a3 swiotlb: fix kernel-doc description for swiotlb_del_transient
Describe the pool argument in the kernel-doc comment for
swiotlb_del_transient.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-13 07:36:10 +02:00
Michael Kelley
7296f2301a swiotlb: reduce swiotlb pool lookups
With CONFIG_SWIOTLB_DYNAMIC enabled, each round-trip map/unmap pair
in the swiotlb results in 6 calls to swiotlb_find_pool(). In multiple
places, the pool is found and used in one function, and then must
be found again in the next function that is called because only the
tlb_addr is passed as an argument. These are the six call sites:

dma_direct_map_page:
 1. swiotlb_map -> swiotlb_tbl_map_single -> swiotlb_bounce

dma_direct_unmap_page:
 2. dma_direct_sync_single_for_cpu -> is_swiotlb_buffer
 3. dma_direct_sync_single_for_cpu -> swiotlb_sync_single_for_cpu ->
	swiotlb_bounce
 4. is_swiotlb_buffer
 5. swiotlb_tbl_unmap_single -> swiotlb_del_transient
 6. swiotlb_tbl_unmap_single -> swiotlb_release_slots

Reduce the number of calls by finding the pool at a higher level, and
passing it as an argument instead of searching again. A key change is
for is_swiotlb_buffer() to return a pool pointer instead of a boolean,
and then pass this pool pointer to subsequent swiotlb functions.

There are 9 occurrences of is_swiotlb_buffer() used to test if a buffer
is a swiotlb buffer before calling a swiotlb function. To reduce code
duplication in getting the pool pointer and passing it as an argument,
introduce inline wrappers for this pattern. The generated code is
essentially unchanged.

Since is_swiotlb_buffer() no longer returns a boolean, rename some
functions to reflect the change:

 * swiotlb_find_pool() becomes __swiotlb_find_pool()
 * is_swiotlb_buffer() becomes swiotlb_find_pool()
 * is_xen_swiotlb_buffer() becomes xen_swiotlb_find_pool()

With these changes, a round-trip map/unmap pair requires only 2 pool
lookups (listed using the new names and wrappers):

dma_direct_unmap_page:
 1. dma_direct_sync_single_for_cpu -> swiotlb_find_pool
 2. swiotlb_tbl_unmap_single -> swiotlb_find_pool

These changes come from noticing the inefficiencies in a code review,
not from performance measurements. With CONFIG_SWIOTLB_DYNAMIC,
__swiotlb_find_pool() is not trivial, and it uses an RCU read lock,
so avoiding the redundant calls helps performance in a hot path.
When CONFIG_SWIOTLB_DYNAMIC is *not* set, the code size reduction
is minimal and the perf benefits are likely negligible, but no
harm is done.

No functional change is intended.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr@tesarici.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-10 07:59:03 +02:00
Yicong Yang
54624acf88 dma-mapping: benchmark: Don't starve others when doing the test
The test thread will start N benchmark kthreads and then schedule out
until the test time finished and notify the benchmark kthreads to stop.
The benchmark kthreads will keep running until notified to stop.
There's a problem with current implementation when the benchmark
kthreads number is equal to the CPUs on a non-preemptible kernel:
since the scheduler will balance the kthreads across the CPUs and
when the test time's out the test thread won't get a chance to be
scheduled on any CPU then cannot notify the benchmark kthreads to stop.

This can be easily reproduced on a VM (simulated with 16 CPUs) with
PREEMPT_VOLUNTARY:
estuary:/mnt$ ./dma_map_benchmark -t 16 -s 1
 rcu: INFO: rcu_sched self-detected stall on CPU
 rcu:     10-...!: (5221 ticks this GP) idle=ed24/1/0x4000000000000000 softirq=142/142 fqs=0
 rcu:     (t=5254 jiffies g=-559 q=45 ncpus=16)
 rcu: rcu_sched kthread starved for 5255 jiffies! g-559 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=12
 rcu:     Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
 rcu: RCU grace-period kthread stack dump:
 task:rcu_sched       state:R  running task     stack:0     pid:16    tgid:16    ppid:2      flags:0x00000008
 Call trace
  __switch_to+0xec/0x138
  __schedule+0x2f8/0x1080
  schedule+0x30/0x130
  schedule_timeout+0xa0/0x188
  rcu_gp_fqs_loop+0x128/0x528
  rcu_gp_kthread+0x1c8/0x208
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20
 Sending NMI from CPU 10 to CPUs 0:
 NMI backtrace for cpu 0
 CPU: 0 PID: 332 Comm: dma-map-benchma Not tainted 6.10.0-rc1-vanilla-LSE #8
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : arm_smmu_cmdq_issue_cmdlist+0x218/0x730
 lr : arm_smmu_cmdq_issue_cmdlist+0x488/0x730
 sp : ffff80008748b630
 x29: ffff80008748b630 x28: 0000000000000000 x27: ffff80008748b780
 x26: 0000000000000000 x25: 000000000000bc70 x24: 000000000001bc70
 x23: ffff0000c12af080 x22: 0000000000010000 x21: 000000000000ffff
 x20: ffff80008748b700 x19: ffff0000c12af0c0 x18: 0000000000010000
 x17: 0000000000000001 x16: 0000000000000040 x15: ffffffffffffffff
 x14: 0001ffffffffffff x13: 000000000000ffff x12: 00000000000002f1
 x11: 000000000001ffff x10: 0000000000000031 x9 : ffff800080b6b0b8
 x8 : ffff0000c2a48000 x7 : 000000000001bc71 x6 : 0001800000000000
 x5 : 00000000000002f1 x4 : 01ffffffffffffff x3 : 000000000009aaf1
 x2 : 0000000000000018 x1 : 000000000000000f x0 : ffff0000c12af18c
 Call trace:
  arm_smmu_cmdq_issue_cmdlist+0x218/0x730
  __arm_smmu_tlb_inv_range+0xe0/0x1a8
  arm_smmu_iotlb_sync+0xc0/0x128
  __iommu_dma_unmap+0x248/0x320
  iommu_dma_unmap_page+0x5c/0xe8
  dma_unmap_page_attrs+0x38/0x1d0
  map_benchmark_thread+0x118/0x2c0
  kthread+0xec/0xf8
  ret_from_fork+0x10/0x20

Solve this by adding scheduling point in the kthread loop,
so if there're other threads in the system they may have
a chance to run, especially the thread to notify the test
end. However this may degrade the test concurrency so it's
recommended to run this on an idle system.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-07-09 07:48:32 +02:00
Fedor Pchelkin
e64746e74f dma-mapping: benchmark: handle NUMA_NO_NODE correctly
cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark()
resulting in the following sanitizer report:

UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28
index -1 is out of range for type 'cpumask [64][1]'
CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
 <TASK>
dump_stack_lvl (lib/dump_stack.c:117)
ubsan_epilogue (lib/ubsan.c:232)
__ubsan_handle_out_of_bounds (lib/ubsan.c:429)
cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline]
do_map_benchmark (kernel/dma/map_benchmark.c:104)
map_benchmark_ioctl (kernel/dma/map_benchmark.c:246)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Use cpumask_of_node() in place when binding a kernel thread to a cpuset
of a particular node.

Note that the provided node id is checked inside map_benchmark_ioctl().
It's just a NUMA_NO_NODE case which is not handled properly later.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-23 15:06:48 +02:00
Fedor Pchelkin
1ff05e723f dma-mapping: benchmark: fix node id validation
While validating node ids in map_benchmark_ioctl(), node_possible() may
be provided with invalid argument outside of [0,MAX_NUMNODES-1] range
leading to:

BUG: KASAN: wild-memory-access in map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
Read of size 8 at addr 1fffffff8ccb6398 by task dma_map_benchma/971
CPU: 7 PID: 971 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
 <TASK>
dump_stack_lvl (lib/dump_stack.c:117)
kasan_report (mm/kasan/report.c:603)
kasan_check_range (mm/kasan/generic.c:189)
variable_test_bit (arch/x86/include/asm/bitops.h:227) [inline]
arch_test_bit (arch/x86/include/asm/bitops.h:239) [inline]
_test_bit at (include/asm-generic/bitops/instrumented-non-atomic.h:142) [inline]
node_state (include/linux/nodemask.h:423) [inline]
map_benchmark_ioctl (kernel/dma/map_benchmark.c:214)
full_proxy_unlocked_ioctl (fs/debugfs/file.c:333)
__x64_sys_ioctl (fs/ioctl.c:890)
do_syscall_64 (arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Compare node ids with sane bounds first. NUMA_NO_NODE is considered a
special valid case meaning that benchmarking kthreads won't be bound to a
cpuset of a given node.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-23 15:06:47 +02:00
Fedor Pchelkin
f7c9ccaadf dma-mapping: benchmark: avoid needless copy_to_user if benchmark fails
If do_map_benchmark() has failed, there is nothing useful to copy back
to userspace.

Suggested-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-23 15:06:47 +02:00
Fedor Pchelkin
bb9025f443 dma-mapping: benchmark: fix up kthread-related error handling
kthread creation failure is invalidly handled inside do_map_benchmark().
The put_task_struct() calls on the error path are supposed to balance the
get_task_struct() calls which only happen after all the kthreads are
successfully created. Rollback using kthread_stop() for already created
kthreads in case of such failure.

In normal situation call kthread_stop_put() to gracefully stop kthreads
and put their task refcounts. This should be done for all started
kthreads.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 65789daa80 ("dma-mapping: add benchmark support for streaming DMA APIs")
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-23 15:06:47 +02:00
Linus Torvalds
daa121128a dma-mapping updates for Linux 6.10
- optimize DMA sync calls when they are no-ops (Alexander Lobakin)
  - fix swiotlb padding for untrusted devices (Michael Kelley)
  - add documentation for swiotb (Michael Kelley)
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Merge tag 'dma-mapping-6.10-2024-05-20' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - optimize DMA sync calls when they are no-ops (Alexander Lobakin)

 - fix swiotlb padding for untrusted devices (Michael Kelley)

 - add documentation for swiotb (Michael Kelley)

* tag 'dma-mapping-6.10-2024-05-20' of git://git.infradead.org/users/hch/dma-mapping:
  dma: fix DMA sync for drivers not calling dma_set_mask*()
  xsk: use generic DMA sync shortcut instead of a custom one
  page_pool: check for DMA sync shortcut earlier
  page_pool: don't use driver-set flags field directly
  page_pool: make sure frag API fields don't span between cachelines
  iommu/dma: avoid expensive indirect calls for sync operations
  dma: avoid redundant calls for sync operations
  dma: compile-out DMA sync op calls when not used
  iommu/dma: fix zeroing of bounce buffer padding used by untrusted devices
  swiotlb: remove alloc_size argument to swiotlb_tbl_map_single()
  Documentation/core-api: add swiotlb documentation
2024-05-20 10:23:39 -07:00
Linus Torvalds
61307b7be4 The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.  Notable
 series include:
 
 - Lucas Stach has provided some page-mapping
   cleanup/consolidation/maintainability work in the series "mm/treewide:
   Remove pXd_huge() API".
 
 - In the series "Allow migrate on protnone reference with
   MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
   MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
   test.
 
 - In their series "Memory allocation profiling" Kent Overstreet and
   Suren Baghdasaryan have contributed a means of determining (via
   /proc/allocinfo) whereabouts in the kernel memory is being allocated:
   number of calls and amount of memory.
 
 - Matthew Wilcox has provided the series "Various significant MM
   patches" which does a number of rather unrelated things, but in largely
   similar code sites.
 
 - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
   Weiner has fixed the page allocator's handling of migratetype requests,
   with resulting improvements in compaction efficiency.
 
 - In the series "make the hugetlb migration strategy consistent" Baolin
   Wang has fixed a hugetlb migration issue, which should improve hugetlb
   allocation reliability.
 
 - Liu Shixin has hit an I/O meltdown caused by readahead in a
   memory-tight memcg.  Addressed in the series "Fix I/O high when memory
   almost met memcg limit".
 
 - In the series "mm/filemap: optimize folio adding and splitting" Kairui
   Song has optimized pagecache insertion, yielding ~10% performance
   improvement in one test.
 
 - Baoquan He has cleaned up and consolidated the early zone
   initialization code in the series "mm/mm_init.c: refactor
   free_area_init_core()".
 
 - Baoquan has also redone some MM initializatio code in the series
   "mm/init: minor clean up and improvement".
 
 - MM helper cleanups from Christoph Hellwig in his series "remove
   follow_pfn".
 
 - More cleanups from Matthew Wilcox in the series "Various page->flags
   cleanups".
 
 - Vlastimil Babka has contributed maintainability improvements in the
   series "memcg_kmem hooks refactoring".
 
 - More folio conversions and cleanups in Matthew Wilcox's series
 
 	"Convert huge_zero_page to huge_zero_folio"
 	"khugepaged folio conversions"
 	"Remove page_idle and page_young wrappers"
 	"Use folio APIs in procfs"
 	"Clean up __folio_put()"
 	"Some cleanups for memory-failure"
 	"Remove page_mapping()"
 	"More folio compat code removal"
 
 - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
   functions to work on folis".
 
 - Code consolidation and cleanup work related to GUP's handling of
   hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
 
 - Rick Edgecombe has developed some fixes to stack guard gaps in the
   series "Cover a guard gap corner case".
 
 - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
   "mm/ksm: fix ksm exec support for prctl".
 
 - Baolin Wang has implemented NUMA balancing for multi-size THPs.  This
   is a simple first-cut implementation for now.  The series is "support
   multi-size THP numa balancing".
 
 - Cleanups to vma handling helper functions from Matthew Wilcox in the
   series "Unify vma_address and vma_pgoff_address".
 
 - Some selftests maintenance work from Dev Jain in the series
   "selftests/mm: mremap_test: Optimizations and style fixes".
 
 - Improvements to the swapping of multi-size THPs from Ryan Roberts in
   the series "Swap-out mTHP without splitting".
 
 - Kefeng Wang has significantly optimized the handling of arm64's
   permission page faults in the series
 
 	"arch/mm/fault: accelerate pagefault when badaccess"
 	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
 
 - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
   GUP-fast".
 
 - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
   use struct vm_fault".
 
 - selftests build fixes from John Hubbard in the series "Fix
   selftests/mm build without requiring "make headers"".
 
 - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
   series "Improved Memory Tier Creation for CPUless NUMA Nodes".  Fixes
   the initialization code so that migration between different memory types
   works as intended.
 
 - David Hildenbrand has improved follow_pte() and fixed an errant driver
   in the series "mm: follow_pte() improvements and acrn follow_pte()
   fixes".
 
 - David also did some cleanup work on large folio mapcounts in his
   series "mm: mapcount for large folios + page_mapcount() cleanups".
 
 - Folio conversions in KSM in Alex Shi's series "transfer page to folio
   in KSM".
 
 - Barry Song has added some sysfs stats for monitoring multi-size THP's
   in the series "mm: add per-order mTHP alloc and swpout counters".
 
 - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
   and limit checking cleanups".
 
 - Matthew Wilcox has been looking at buffer_head code and found the
   documentation to be lacking.  The series is "Improve buffer head
   documentation".
 
 - Multi-size THPs get more work, this time from Lance Yang.  His series
   "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
   the freeing of these things.
 
 - Kemeng Shi has added more userspace-visible writeback instrumentation
   in the series "Improve visibility of writeback".
 
 - Kemeng Shi then sent some maintenance work on top in the series "Fix
   and cleanups to page-writeback".
 
 - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
   series "Improve anon_vma scalability for anon VMAs".  Intel's test bot
   reported an improbable 3x improvement in one test.
 
 - SeongJae Park adds some DAMON feature work in the series
 
 	"mm/damon: add a DAMOS filter type for page granularity access recheck"
 	"selftests/damon: add DAMOS quota goal test"
 
 - Also some maintenance work in the series
 
 	"mm/damon/paddr: simplify page level access re-check for pageout"
 	"mm/damon: misc fixes and improvements"
 
 - David Hildenbrand has disabled some known-to-fail selftests ni the
   series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
 
 - memcg metadata storage optimizations from Shakeel Butt in "memcg:
   reduce memory consumption by memcg stats".
 
 - DAX fixes and maintenance work from Vishal Verma in the series
   "dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
2024-05-19 09:21:03 -07:00
Alexander Lobakin
a6016aac52 dma: fix DMA sync for drivers not calling dma_set_mask*()
There are several reports that the DMA sync shortcut broke non-coherent
devices.
dev->dma_need_sync is false after the &device allocation and if a driver
didn't call dma_set_mask*(), it will still be false even if the device
is not DMA-coherent and thus needs synchronizing. Due to historical
reasons, there's still a lot of drivers not calling it.
Invert the boolean, so that the sync will be performed by default and
the shortcut will be enabled only when calling dma_set_mask*().

Reported-by: Steven Price <steven.price@arm.com>
Closes: https://lore.kernel.org/lkml/010686f5-3049-46a1-8230-7752a1b433ff@arm.com
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Closes: https://lore.kernel.org/lkml/46160534-5003-4809-a408-6b3a3f4921e9@samsung.com
Fixes: f406c8e4b7. ("dma: avoid redundant calls for sync operations")
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Steven Price <steven.price@arm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
2024-05-09 19:00:29 +02:00
Alexander Lobakin
f406c8e4b7 dma: avoid redundant calls for sync operations
Quite often, devices do not need dma_sync operations on x86_64 at least.
Indeed, when dev_is_dma_coherent(dev) is true and
dev_use_swiotlb(dev) is false, iommu_dma_sync_single_for_cpu()
and friends do nothing.

However, indirectly calling them when CONFIG_RETPOLINE=y consumes about
10% of cycles on a cpu receiving packets from softirq at ~100Gbit rate.
Even if/when CONFIG_RETPOLINE is not set, there is a cost of about 3%.

Add dev->need_dma_sync boolean and turn it off during the device
initialization (dma_set_mask()) depending on the setup:
dev_is_dma_coherent() for the direct DMA, !(sync_single_for_device ||
sync_single_for_cpu) or the new dma_map_ops flag, %DMA_F_CAN_SKIP_SYNC,
advertised for non-NULL DMA ops.
Then later, if/when swiotlb is used for the first time, the flag
is reset back to on, from swiotlb_tbl_map_single().

On iavf, the UDP trafficgen with XDP_DROP in skb mode test shows
+3-5% increase for direct DMA.

Suggested-by: Christoph Hellwig <hch@lst.de> # direct DMA shortcut
Co-developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-07 13:29:53 +02:00
Alexander Lobakin
fe7514b149 dma: compile-out DMA sync op calls when not used
Some platforms do have DMA, but DMA there is always direct and coherent.
Currently, even on such platforms DMA sync operations are compiled and
called.
Add a new hidden Kconfig symbol, DMA_NEED_SYNC, and set it only when
either sync operations are needed or there is DMA ops or swiotlb
or DMA debug is enabled. Compile global dma_sync_*() and dma_need_sync()
only when it's set, otherwise provide empty inline stubs.
The change allows for future optimizations of DMA sync calls depending
on runtime conditions.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-07 13:29:53 +02:00
Michael Kelley
327e2c97c4 swiotlb: remove alloc_size argument to swiotlb_tbl_map_single()
Currently swiotlb_tbl_map_single() takes alloc_align_mask and
alloc_size arguments to specify an swiotlb allocation that is larger
than mapping_size.  This larger allocation is used solely by
iommu_dma_map_single() to handle untrusted devices that should not have
DMA visibility to memory pages that are partially used for unrelated
kernel data.

Having two arguments to specify the allocation is redundant. While
alloc_align_mask naturally specifies the alignment of the starting
address of the allocation, it can also implicitly specify the size
by rounding up the mapping_size to that alignment.

Additionally, the current approach has an edge case bug.
iommu_dma_map_page() already does the rounding up to compute the
alloc_size argument. But swiotlb_tbl_map_single() then calculates the
alignment offset based on the DMA min_align_mask, and adds that offset to
alloc_size. If the offset is non-zero, the addition may result in a value
that is larger than the max the swiotlb can allocate.  If the rounding up
is done _after_ the alignment offset is added to the mapping_size (and
the original mapping_size conforms to the value returned by
swiotlb_max_mapping_size), then the max that the swiotlb can allocate
will not be exceeded.

In view of these issues, simplify the swiotlb_tbl_map_single() interface
by removing the alloc_size argument. Most call sites pass the same value
for mapping_size and alloc_size, and they pass alloc_align_mask as zero.
Just remove the redundant argument from these callers, as they will see
no functional change. For iommu_dma_map_page() also remove the alloc_size
argument, and have swiotlb_tbl_map_single() compute the alloc_size by
rounding up mapping_size after adding the offset based on min_align_mask.
This has the side effect of fixing the edge case bug but with no other
functional change.

Also add a sanity test on the alloc_align_mask. While IOMMU code
currently ensures the granule is not larger than PAGE_SIZE, if that
guarantee were to be removed in the future, the downstream effect on the
swiotlb might go unnoticed until strange allocation failures occurred.

Tested on an ARM64 system with 16K page size and some kernel test-only
hackery to allow modifying the DMA min_align_mask and the granule size
that becomes the alloc_align_mask. Tested these combinations with a
variety of original memory addresses and sizes, including those that
reproduce the edge case bug:

 * 4K granule and 0 min_align_mask
 * 4K granule and 0xFFF min_align_mask (4K - 1)
 * 16K granule and 0xFFF min_align_mask
 * 64K granule and 0xFFF min_align_mask
 * 64K granule and 0x3FFF min_align_mask (16K - 1)

With the changes, all combinations pass.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr@tesarici.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-07 13:29:28 +02:00
Will Deacon
75961ffb5c swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=y
Using restricted DMA pools (CONFIG_DMA_RESTRICTED_POOL=y) in conjunction
with dynamic SWIOTLB (CONFIG_SWIOTLB_DYNAMIC=y) leads to the following
crash when initialising the restricted pools at boot-time:

  | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
  | Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
  | pc : rmem_swiotlb_device_init+0xfc/0x1ec
  | lr : rmem_swiotlb_device_init+0xf0/0x1ec
  | Call trace:
  |  rmem_swiotlb_device_init+0xfc/0x1ec
  |  of_reserved_mem_device_init_by_idx+0x18c/0x238
  |  of_dma_configure_id+0x31c/0x33c
  |  platform_dma_configure+0x34/0x80

faddr2line reveals that the crash is in the list validation code:

  include/linux/list.h:83
  include/linux/rculist.h:79
  include/linux/rculist.h:106
  kernel/dma/swiotlb.c:306
  kernel/dma/swiotlb.c:1695

because add_mem_pool() is trying to list_add_rcu() to a NULL
'mem->pools'.

Fix the crash by initialising the 'mem->pools' list_head in
rmem_swiotlb_device_init() before calling add_mem_pool().

Reported-by: Nikita Ioffe <ioffe@google.com>
Tested-by: Nikita Ioffe <ioffe@google.com>
Fixes: 1aaa736815 ("swiotlb: allocate a new memory pool when existing pools are full")
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-05-02 14:57:04 +02:00
Suren Baghdasaryan
8a2f118787 change alloc_pages name in dma_map_ops to avoid name conflicts
After redefining alloc_pages, all uses of that name are being replaced. 
Change the conflicting names to prevent preprocessor from replacing them
when it's not intended.

Link: https://lkml.kernel.org/r/20240321163705.3067592-18-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:53 -07:00
Dexuan Cui
a1255ccab8 swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files()
Sometimes the readout of /sys/kernel/debug/swiotlb/io_tlb_used and
io_tlb_used_hiwater can be a huge number (e.g. 18446744073709551615),
which is actually a negative number if we use "%ld" to print the number.

When swiotlb_create_default_debugfs() is running from late_initcall,
mem->total_used may already be non-zero, because the storage driver
may have already started to perform I/O operations: if the storage
driver is built-in, its probe() callback is called before late_initcall.

swiotlb_create_debugfs_files() should not blindly set mem->total_used
and mem->used_hiwater to 0; actually it doesn't have to initialize the
fields at all, because the fields, as part of the global struct
io_tlb_default_mem, have been implicitly initialized to zero.

Also don't explicitly set mem->transient_nslabs to 0.

Fixes: 8b0977ecc8 ("swiotlb: track and report io_tlb_used high water marks in debugfs")
Fixes: 02e7656970 ("swiotlb: add debugfs to track swiotlb transient pool usage")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-04-02 17:08:09 +02:00
Michael Kelley
e8068f2d75 swiotlb: fix swiotlb_bounce() to do partial sync's correctly
In current code, swiotlb_bounce() may do partial sync's correctly in
some circumstances, but may incorrectly fail in other circumstances.
The failure cases require both of these to be true:

1) swiotlb_align_offset() returns a non-zero "offset" value
2) the tlb_addr of the partial sync area points into the first
"offset" bytes of the _second_ or subsequent swiotlb slot allocated
for the mapping

Code added in commit 868c9ddc18 ("swiotlb: add overflow checks
to swiotlb_bounce") attempts to WARN on the invalid case where
tlb_addr points into the first "offset" bytes of the _first_
allocated slot. But there's no way for swiotlb_bounce() to distinguish
the first slot from the second and subsequent slots, so the WARN
can be triggered incorrectly when #2 above is true.

Related, current code calculates an adjustment to the orig_addr stored
in the swiotlb slot. The adjustment compensates for the difference
in the tlb_addr used for the partial sync vs. the tlb_addr for the full
mapping. The adjustment is stored in the local variable tlb_offset.
But when #1 and #2 above are true, it's valid for this adjustment to
be negative. In such case the arithmetic to adjust orig_addr produces
the wrong result due to tlb_offset being declared as unsigned.

Fix these problems by removing the over-constraining validations added
in 868c9ddc18. Change the declaration of tlb_offset to be signed
instead of unsigned so the adjustment arithmetic works correctly.

Tested with a test-only hack to how swiotlb_tbl_map_single() calls
swiotlb_bounce(). Instead of calling swiotlb_bounce() just once
for the entire mapped area, do a loop with each iteration doing
only a 128 byte partial sync until the entire mapped area is
sync'ed. Then with swiotlb=force on the kernel boot line, run a
variety of raw disk writes followed by read and verification of
all bytes of the written data. The storage device has DMA
min_align_mask set, and the writes are done with a variety of
original buffer memory address alignments and overall buffer
sizes. For many of the combinations, current code triggers the
WARN statements, or the data verification fails. With the fixes,
no WARNs occur and all verifications pass.

Fixes: 5f89468e2f ("swiotlb: manipulate orig_addr when tlb_addr has offset")
Fixes: 868c9ddc18 ("swiotlb: add overflow checks to swiotlb_bounce")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Dominique Martinet <dominique.martinet@atmark-techno.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-04-02 17:08:03 +02:00
Petr Tesarik
af133562d5 swiotlb: extend buffer pre-padding to alloc_align_mask if necessary
Allow a buffer pre-padding of up to alloc_align_mask, even if it requires
allocating additional IO TLB slots.

If the allocation alignment is bigger than IO_TLB_SIZE and min_align_mask
covers any non-zero bits in the original address between IO_TLB_SIZE and
alloc_align_mask, these bits are not preserved in the swiotlb buffer
address.

To fix this case, increase the allocation size and use a larger offset
within the allocated buffer. As a result, extra padding slots may be
allocated before the mapping start address.

Leave orig_addr in these padding slots initialized to INVALID_PHYS_ADDR.
These slots do not correspond to any CPU buffer, so attempts to sync the
data should be ignored.

The padding slots should be automatically released when the buffer is
unmapped. However, swiotlb_tbl_unmap_single() takes only the address of the
DMA buffer slot, not the first padding slot. Save the number of padding
slots in struct io_tlb_slot and use it to adjust the slot index in
swiotlb_release_slots(), so all allocated slots are properly freed.

Fixes: 2fd4fa5d3fb5 ("swiotlb: Fix alignment checks when both allocation and DMA masks are present")
Link: https://lore.kernel.org/linux-iommu/20240311210507.217daf8b@meshulam.tesarici.cz/
Signed-off-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-04-02 17:07:57 +02:00
Linus Torvalds
864ad046c1 dma-mapping fixes for Linux 6.9
This has a set of swiotlb alignment fixes for sometimes very long
 standing bugs from Will.  We've been discussion them for a while and they
 should be solid now.
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Merge tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "This has a set of swiotlb alignment fixes for sometimes very long
  standing bugs from Will. We've been discussion them for a while and
  they should be solid now"

* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
  iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
  swiotlb: Fix alignment checks when both allocation and DMA masks are present
  swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
  swiotlb: Enforce page alignment in swiotlb_alloc()
  swiotlb: Fix double-allocation of slots due to broken alignment handling
2024-03-24 10:45:31 -07:00
Linus Torvalds
902861e34c - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory.  Series
   "implement "memmap on memory" feature on s390".
 
 - More folio conversions from Matthew Wilcox in the series
 
 	"Convert memcontrol charge moving to use folios"
 	"mm: convert mm counter to take a folio"
 
 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes.  The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".
 
 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.
 
 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools".  Measured improvements are modest.
 
 - zswap cleanups and simplifications from Yosry Ahmed in the series "mm:
   zswap: simplify zswap_swapoff()".
 
 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is hotplugged
   as system memory.
 
 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.
 
 - More DAMON work from SeongJae Park in the series
 
 	"mm/damon: make DAMON debugfs interface deprecation unignorable"
 	"selftests/damon: add more tests for core functionalities and corner cases"
 	"Docs/mm/damon: misc readability improvements"
 	"mm/damon: let DAMOS feeds and tame/auto-tune itself"
 
 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving policy
   wherein we allocate memory across nodes in a weighted fashion rather
   than uniformly.  This is beneficial in heterogeneous memory environments
   appearing with CXL.
 
 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
 
 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".
 
 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format.  Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.
 
 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP".  Mainly
   targeted at arm64, this significantly speeds up fork() when the process
   has a large number of pte-mapped folios.
 
 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP".  It
   implements batching during munmap() and other pte teardown situations.
   The microbenchmark improvements are nice.
 
 - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan
   Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings").  Kernel build times on arm64 improved nicely.  Ryan's series
   "Address some contpte nits" provides some followup work.
 
 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page faults.
   He has also added a reproducer under the selftest code.
 
 - In the series "selftests/mm: Output cleanups for the compaction test",
   Mark Brown did what the title claims.
 
 - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring".
 
 - Even more zswap material from Nhat Pham.  The series "fix and extend
   zswap kselftests" does as claimed.
 
 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in
   our handling of DAX on archiecctures which have virtually aliasing data
   caches.  The arm architecture is the main beneficiary.
 
 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic
   improvements in worst-case mmap_lock hold times during certain
   userfaultfd operations.
 
 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series
 
 	"page_owner: print stacks and their outstanding allocations"
 	"page_owner: Fixup and cleanup"
 
 - Uladzislau Rezki has contributed some vmalloc scalability improvements
   in his series "Mitigate a vmap lock contention".  It realizes a 12x
   improvement for a certain microbenchmark.
 
 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".
 
 - Some zsmalloc maintenance work from Chengming Zhou in the series
 
 	"mm/zsmalloc: fix and optimize objects/page migration"
 	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
 
 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0.  This a step along the path to implementaton of the merging of
   large anonymous folios.  The series is named "Enable >0 order folio
   memory compaction".
 
 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages() to
   an iterator".
 
 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".
 
 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios.  The
   series is named "Split a folio to any lower order folios".
 
 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.
 
 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".
 
 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which are
   configured to use large numbers of hugetlb pages.
 
 - Matthew Wilcox's series "PageFlags cleanups" does that.
 
 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also.  S390 is affected.
 
 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".
 
 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM Selftests".
 
 - Also, of course, many singleton patches to many things.  Please see
   the individual changelogs for details.
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Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...
2024-03-14 17:43:30 -07:00
Will Deacon
14cebf689a swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
For swiotlb allocations >= PAGE_SIZE, the slab search historically
adjusted the stride to avoid checking unaligned slots. This had the
side-effect of aligning large mapping requests to PAGE_SIZE, but that
was broken by 0eee5ae102 ("swiotlb: fix slot alignment checks").

Since this alignment could be relied upon drivers, reinstate PAGE_SIZE
alignment for swiotlb mappings >= PAGE_SIZE.

Reported-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-03-13 11:39:34 -07:00
Will Deacon
51b30ecb73 swiotlb: Fix alignment checks when both allocation and DMA masks are present
Nicolin reports that swiotlb buffer allocations fail for an NVME device
behind an IOMMU using 64KiB pages. This is because we end up with a
minimum allocation alignment of 64KiB (for the IOMMU to map the buffer
safely) but a minimum DMA alignment mask corresponding to a 4KiB NVME
page (i.e. preserving the 4KiB page offset from the original allocation).
If the original address is not 4KiB-aligned, the allocation will fail
because swiotlb_search_pool_area() erroneously compares these unmasked
bits with the 64KiB-aligned candidate allocation.

Tweak swiotlb_search_pool_area() so that the DMA alignment mask is
reduced based on the required alignment of the allocation.

Fixes: 82612d66d5 ("iommu: Allow the dma-iommu api to use bounce buffers")
Link: https://lore.kernel.org/r/cover.1707851466.git.nicolinc@nvidia.com
Reported-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-03-13 11:39:27 -07:00
Will Deacon
cbf53074a5 swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
core-api/dma-api-howto.rst states the following properties of
dma_alloc_coherent():

  | The CPU virtual address and the DMA address are both guaranteed to
  | be aligned to the smallest PAGE_SIZE order which is greater than or
  | equal to the requested size.

However, swiotlb_alloc() passes zero for the 'alloc_align_mask'
parameter of swiotlb_find_slots() and so this property is not upheld.
Instead, allocations larger than a page are aligned to PAGE_SIZE,

Calculate the mask corresponding to the page order suitable for holding
the allocation and pass that to swiotlb_find_slots().

Fixes: e81e99bacc ("swiotlb: Support aligned swiotlb buffers")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-03-13 11:39:24 -07:00
Will Deacon
823353b7cf swiotlb: Enforce page alignment in swiotlb_alloc()
When allocating pages from a restricted DMA pool in swiotlb_alloc(),
the buffer address is blindly converted to a 'struct page *' that is
returned to the caller. In the unlikely event of an allocation bug,
page-unaligned addresses are not detected and slots can silently be
double-allocated.

Add a simple check of the buffer alignment in swiotlb_alloc() to make
debugging a little easier if something has gone wonky.

Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-03-13 11:39:22 -07:00
Will Deacon
04867a7a33 swiotlb: Fix double-allocation of slots due to broken alignment handling
Commit bbb73a103f ("swiotlb: fix a braino in the alignment check fix"),
which was a fix for commit 0eee5ae102 ("swiotlb: fix slot alignment
checks"), causes a functional regression with vsock in a virtual machine
using bouncing via a restricted DMA SWIOTLB pool.

When virtio allocates the virtqueues for the vsock device using
dma_alloc_coherent(), the SWIOTLB search can return page-unaligned
allocations if 'area->index' was left unaligned by a previous allocation
from the buffer:

 # Final address in brackets is the SWIOTLB address returned to the caller
 | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1645-1649/7168 (0x98326800)
 | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1649-1653/7168 (0x98328800)
 | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1653-1657/7168 (0x9832a800)

This ends badly (typically buffer corruption and/or a hang) because
swiotlb_alloc() is expecting a page-aligned allocation and so blindly
returns a pointer to the 'struct page' corresponding to the allocation,
therefore double-allocating the first half (2KiB slot) of the 4KiB page.

Fix the problem by treating the allocation alignment separately to any
additional alignment requirements from the device, using the maximum
of the two as the stride to search the buffer slots and taking care
to ensure a minimum of page-alignment for buffers larger than a page.

This also resolves swiotlb allocation failures occuring due to the
inclusion of ~PAGE_MASK in 'iotlb_align_mask' for large allocations and
resulting in alignment requirements exceeding swiotlb_max_mapping_size().

Fixes: bbb73a103f ("swiotlb: fix a braino in the alignment check fix")
Fixes: 0eee5ae102 ("swiotlb: fix slot alignment checks")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-03-13 11:39:17 -07:00
Rick Edgecombe
b9fa16949d dma-direct: Leak pages on dma_set_decrypted() failure
On TDX it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

DMA could free decrypted/shared pages if dma_set_decrypted() fails. This
should be a rare case. Just leak the pages in this case instead of
freeing them.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-02-28 05:31:38 -08:00
ZhangPeng
02e7656970 swiotlb: add debugfs to track swiotlb transient pool usage
Introduce a new debugfs interface io_tlb_transient_nslabs. The device
driver can create a new swiotlb transient memory pool once default
memory pool is full. To export the swiotlb transient memory pool usage
via debugfs would help the user estimate the size of transient swiotlb
memory pool or analyze device driver memory leak issue.

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-02-28 05:31:38 -08:00
Anshuman Khandual
fe58582c0e mm/cma: drop CONFIG_CMA_DEBUG
All pr_debug() prints in (mm/cma.c) could be enabled via standard Makefile
based method.  Besides cma_debug_show_areas() should always be called
during cma_alloc() failure path.  This seemingly redundant config,
CONFIG_CMA_DEBUG can be dropped without any problem.

[lukas.bulwahn@gmail.com: remove debug code to removed CONFIG_CMA_DEBUG]
  Link: https://lkml.kernel.org/r/20240207143825.986-1-lukas.bulwahn@gmail.com
Link: https://lkml.kernel.org/r/20240205031647.283510-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:53 -08:00