This reverts commits:
5e46e29e6a ("powerpc/64s/hash: convert SLB miss handlers to C")
8fed04d0f6 ("powerpc/64s/hash: remove user SLB data from the paca")
655deecf67 ("powerpc/64s/hash: SLB allocation status bitmaps")
2e1626744e ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup")
89ca4e126a ("powerpc/64s/hash: Add a SLB preload cache")
This series had a few bugs, and the fixes are not all trivial. So
revert most of it for now.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When switching processes, currently all user SLBEs are cleared, and a
few (exec_base, pc, and stack) are preloaded. In trivial testing with
small apps, this tends to miss the heap and low 256MB segments, and it
will also miss commonly accessed segments on large memory workloads.
Add a simple round-robin preload cache that just inserts the last SLB
miss into the head of the cache and preloads those at context switch
time. Every 256 context switches, the oldest entry is removed from the
cache to shrink the cache and require fewer slbmte if they are unused.
Much more could go into this, including into the SLB entry reclaim
side to track some LRU information etc, which would require a study of
large memory workloads. But this is a simple thing we can do now that
is an obvious win for common workloads.
With the full series, process switching speed on the context_switch
benchmark on POWER9/hash (with kernel speculation security masures
disabled) increases from 140K/s to 178K/s (27%).
POWER8 does not change much (within 1%), it's unclear why it does not
see a big gain like POWER9.
Booting to busybox init with 256MB segments has SLB misses go down
from 945 to 69, and with 1T segments 900 to 21. These could almost all
be eliminated by preloading a bit more carefully with ELF binary
loading.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add 32-entry bitmaps to track the allocation status of the first 32
SLB entries, and whether they are user or kernel entries. These are
used to allocate free SLB entries first, before resorting to the round
robin allocator.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
User SLB mappig data is copied into the PACA from the mm->context so
it can be accessed by the SLB miss handlers.
After the C conversion, SLB miss handlers now run with relocation on,
and user SLB misses are able to take recursive kernel SLB misses, so
the user SLB mapping data can be removed from the paca and accessed
directly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.
This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.
Arbitrary kernel memory may not be accessed when handling kernel space
SLB misses, so care should be taken there. However user SLB misses can
access any kernel memory, which can be used to move some fields out of
the paca (in later patches).
User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.
[ Credit to Aneesh for bug fixes, error checks, and improvements to bad
address handling, etc ]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Since RFC:
- Added MSR[RI] handling
- Fixed up a register loss bug exposed by irq tracing (Aneesh)
- Reject misses outside the defined kernel regions (Aneesh)
- Added several more sanity checks and error handling (Aneesh), we may
look at consolidating these tests and tightenig up the code but for
a first pass we decided it's better to check carefully.
Since v1:
- Fixed SLB cache corruption (Aneesh)
- Fixed untidy SLBE allocation "leak" in get_vsid error case
- Now survives some stress testing on real hardware
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 introduces SLBIA IH=3, which invalidates all SLB entries and
associated lookaside information that have a class value of 1, which
Linux assigns to user addresses. This matches what switch_slb wants,
and allows a simple fast implementation that avoids the slb_cache
complexity.
As a side-effect, the POWER5 < DD2.1 SLB invalidation workaround is
also avoided on POWER9.
Process context switching rate is improved about 2.2% for a small
process that hits the slb cache which is the best case for the current
code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The SLBIA IH=1 hint will remove all non-zero SLBEs, but only
invalidate ERAT entries associated with a class value of 1, for
processors that support the hint (e.g., POWER6 and newer), which
Linux assigns to user addresses.
This prevents kernel ERAT entries from being invalidated when
context switchig (if the thread faulted in more than 8 user SLBEs).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove the vmalloc segment from bolted SLBEs. This is not required to
be bolted, and seems like it was added to help pre-load the SLB on
context switch. However there are now other segments like the vmemmap
segment and non-zero node memory that often take misses after a context
switch, so it is better to solve this in a more general way.
A subsequent change will track free SLB entries and uses those rather
than round-robin overwrite valid entries, which makes it far less
likely for kernel SLBEs to be evicted after they are installed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The POWER5 < DD2.1 issue is that slbie needs to be issued more than
once. It came in with this change:
ChangeSet@1.1608, 2004-04-29 07:12:31-07:00, david@gibson.dropbear.id.au
[PATCH] POWER5 erratum workaround
Early POWER5 revisions (<DD2.1) have a problem requiring slbie
instructions to be repeated under some circumstances. The patch below
adds a workaround (patch made by Anton Blanchard).
(aka. 3e4520f7605243abf66a7ccd3d2e49e48e8c0483 in the full history tree)
The extra slbie in switch_slb is done even for the case where slbia is
called (slb_flush_and_rebolt). I don't believe that is required
because there are other slb_flush_and_rebolt callers which do not
issue the workaround slbie, which would be broken if it was required.
It also seems to be fine inside the isync with the first slbie, as it
is in the kernel stack switch code.
So move this workaround to where it is required. This is not much of
an optimisation because this is the fast path, but it makes the code
more understandable and neater.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain slbie_data initialisation to avoid compiler warning]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
I only have POWER8/9 to test, so just remove it for those.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This causes SLB alloation to start 1 beyond the start of the SLB.
There is no real problem because after it wraps it stats behaving
properly, it's just surprisig to see when looking at SLB traces.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull IDA updates from Matthew Wilcox:
"A better IDA API:
id = ida_alloc(ida, GFP_xxx);
ida_free(ida, id);
rather than the cumbersome ida_simple_get(), ida_simple_remove().
The new IDA API is similar to ida_simple_get() but better named. The
internal restructuring of the IDA code removes the bitmap
preallocation nonsense.
I hope the net -200 lines of code is convincing"
* 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits)
ida: Change ida_get_new_above to return the id
ida: Remove old API
test_ida: check_ida_destroy and check_ida_alloc
test_ida: Convert check_ida_conv to new API
test_ida: Move ida_check_max
test_ida: Move ida_check_leaf
idr-test: Convert ida_check_nomem to new API
ida: Start new test_ida module
target/iscsi: Allocate session IDs from an IDA
iscsi target: fix session creation failure handling
drm/vmwgfx: Convert to new IDA API
dmaengine: Convert to new IDA API
ppc: Convert vas ID allocation to new IDA API
media: Convert entity ID allocation to new IDA API
ppc: Convert mmu context allocation to new IDA API
Convert net_namespace to new IDA API
cb710: Convert to new IDA API
rsxx: Convert to new IDA API
osd: Convert to new IDA API
sd: Convert to new IDA API
...
- An implementation for the newly added hv_ops->flush() for the OPAL hvc
console driver backends, I forgot to apply this after merging the hvc driver
changes before the merge window.
- Enable all PCI bridges at boot on powernv, to avoid races when multiple
children of a bridge try to enable it simultaneously. This is a workaround
until the PCI core can be enhanced to fix the races.
- A fix to query PowerVM for the correct system topology at boot before
initialising sched domains, seen in some configurations to cause broken
scheduling etc.
- A fix for pte_access_permitted() on "nohash" platforms.
- Two commits to fix SIGBUS when using remap_pfn_range() seen on Power9 due to
a workaround when using the nest MMU (GPUs, accelerators).
- Another fix to the VFIO code used by KVM, the previous fix had some bugs
which caused guests to not start in some configurations.
- A handful of other minor fixes.
Thanks to:
Aneesh Kumar K.V, Benjamin Herrenschmidt, Christophe Leroy, Hari Bathini, Luke
Dashjr, Mahesh Salgaonkar, Nicholas Piggin, Paul Mackerras, Srikar Dronamraju.
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Merge tag 'powerpc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- An implementation for the newly added hv_ops->flush() for the OPAL
hvc console driver backends, I forgot to apply this after merging the
hvc driver changes before the merge window.
- Enable all PCI bridges at boot on powernv, to avoid races when
multiple children of a bridge try to enable it simultaneously. This
is a workaround until the PCI core can be enhanced to fix the races.
- A fix to query PowerVM for the correct system topology at boot before
initialising sched domains, seen in some configurations to cause
broken scheduling etc.
- A fix for pte_access_permitted() on "nohash" platforms.
- Two commits to fix SIGBUS when using remap_pfn_range() seen on Power9
due to a workaround when using the nest MMU (GPUs, accelerators).
- Another fix to the VFIO code used by KVM, the previous fix had some
bugs which caused guests to not start in some configurations.
- A handful of other minor fixes.
Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Christophe Leroy,
Hari Bathini, Luke Dashjr, Mahesh Salgaonkar, Nicholas Piggin, Paul
Mackerras, Srikar Dronamraju.
* tag 'powerpc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/mce: Fix SLB rebolting during MCE recovery path.
KVM: PPC: Book3S: Fix guest DMA when guest partially backed by THP pages
powerpc/mm/radix: Only need the Nest MMU workaround for R -> RW transition
powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.
powerpc/nohash: fix pte_access_permitted()
powerpc/topology: Get topology for shared processors at boot
powerpc64/ftrace: Include ftrace.h needed for enable/disable calls
powerpc/powernv/pci: Work around races in PCI bridge enabling
powerpc/fadump: cleanup crash memory ranges support
powerpc/powernv: provide a console flush operation for opal hvc driver
powerpc/traps: Avoid rate limit messages from show unhandled signals
powerpc/64s: Fix PACA_IRQ_HARD_DIS accounting in idle_power4()
The commit e7e8184747 ("powerpc/64s: move machine check SLB flushing
to mm/slb.c") introduced a bug in reloading bolted SLB entries. Unused
bolted entries are stored with .esid=0 in the slb_shadow area, and
that value is now used directly as the RB input to slbmte, which means
the RB[52:63] index field is set to 0, which causes SLB entry 0 to be
cleared.
Fix this by storing the index bits in the unused bolted entries, which
directs the slbmte to the right place.
The SLB shadow area is also used by the hypervisor, but PAPR is okay
with that, from LoPAPR v1.1, 14.11.1.3 SLB Shadow Buffer:
Note: SLB is filled sequentially starting at index 0
from the shadow buffer ignoring the contents of
RB field bits 52-63
Fixes: e7e8184747 ("powerpc/64s: move machine check SLB flushing to mm/slb.c")
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 76fa4975f3 ("KVM: PPC: Check if IOMMU page is contained in
the pinned physical page", 2018-07-17) added some checks to ensure
that guest DMA mappings don't attempt to map more than the guest is
entitled to access. However, errors in the logic mean that legitimate
guest requests to map pages for DMA are being denied in some
situations. Specifically, if the first page of the range passed to
mm_iommu_get() is mapped with a normal page, and subsequent pages are
mapped with transparent huge pages, we end up with mem->pageshift ==
0. That means that the page size checks in mm_iommu_ua_to_hpa() and
mm_iommu_up_to_hpa_rm() will always fail for every page in that
region, and thus the guest can never map any memory in that region for
DMA, typically leading to a flood of error messages like this:
qemu-system-ppc64: VFIO_MAP_DMA: -22
qemu-system-ppc64: vfio_dma_map(0x10005f47780, 0x800000000000000, 0x10000, 0x7fff63ff0000) = -22 (Invalid argument)
The logic errors in mm_iommu_get() are:
(a) use of 'ua' not 'ua + (i << PAGE_SHIFT)' in the find_linux_pte()
call (meaning that find_linux_pte() returns the pte for the
first address in the range, not the address we are currently up
to);
(b) use of 'pageshift' as the variable to receive the hugepage shift
returned by find_linux_pte() - for a normal page this gets set
to 0, leading to us setting mem->pageshift to 0 when we conclude
that the pte returned by find_linux_pte() didn't match the page
we were looking at;
(c) comparing 'compshift', which is a page order, i.e. log base 2 of
the number of pages, with 'pageshift', which is a log base 2 of
the number of bytes.
To fix these problems, this patch introduces 'cur_ua' to hold the
current user address and uses that in the find_linux_pte() call;
introduces 'pteshift' to hold the hugepage shift found by
find_linux_pte(); and compares 'pteshift' with 'compshift +
PAGE_SHIFT' rather than 'compshift'.
The patch also moves the local_irq_restore to the point after the PTE
pointer returned by find_linux_pte() has been dereferenced because
otherwise the PTE could change underneath us, and adds a check to
avoid doing the find_linux_pte() call once mem->pageshift has been
reduced to PAGE_SHIFT, as an optimization.
Fixes: 76fa4975f3 ("KVM: PPC: Check if IOMMU page is contained in the pinned physical page")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Nest MMU workaround is only needed for RW upgrades. Avoid doing
that for other PTE updates.
We also avoid clearing the PTE while marking it invalid. This is
because other page table walkers will find this PTE none and can
result in unexpected behaviour due to that. Instead we clear
_PAGE_PRESENT and set the software PTE bit _PAGE_INVALID.
pte_present() is already updated to check for both bits. This makes
sure page table walkers will find the PTE present and things like
pte_pfn(pte) returns the right value.
Based on an original patch from Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ida_alloc_range is the perfect fit for this use case. Eliminates
a custom spinlock, a call to ida_pre_get and a local check for the
allocated ID exceeding a maximum.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
On a shared LPAR, Phyp will not update the CPU associativity at boot
time. Just after the boot system does recognize itself as a shared
LPAR and trigger a request for correct CPU associativity. But by then
the scheduler would have already created/destroyed its sched domains.
This causes
- Broken load balance across Nodes causing islands of cores.
- Performance degradation esp if the system is lightly loaded
- dmesg to wrongly report all CPUs to be in Node 0.
- Messages in dmesg saying borken topology.
- With commit 051f3ca02e ("sched/topology: Introduce NUMA identity
node sched domain"), can cause rcu stalls at boot up.
The sched_domains_numa_masks table which is used to generate cpumasks
is only created at boot time just before creating sched domains and
never updated. Hence, its better to get the topology correct before
the sched domains are created.
For example on 64 core Power 8 shared LPAR, dmesg reports
Brought up 512 CPUs
Node 0 CPUs: 0-511
Node 1 CPUs:
Node 2 CPUs:
Node 3 CPUs:
Node 4 CPUs:
Node 5 CPUs:
Node 6 CPUs:
Node 7 CPUs:
Node 8 CPUs:
Node 9 CPUs:
Node 10 CPUs:
Node 11 CPUs:
...
BUG: arch topology borken
the DIE domain not a subset of the NUMA domain
BUG: arch topology borken
the DIE domain not a subset of the NUMA domain
numactl/lscpu output will still be correct with cores spreading across
all nodes:
Socket(s): 64
NUMA node(s): 12
Model: 2.0 (pvr 004d 0200)
Model name: POWER8 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 64K
L1i cache: 32K
NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471
NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479
NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487
NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495
NUMA node4 CPU(s): 208-215,304-311,400-407,496-503
NUMA node5 CPU(s): 168-175,264-271,360-367,456-463
NUMA node6 CPU(s): 128-135,224-231,320-327,416-423
NUMA node7 CPU(s): 136-143,232-239,328-335,424-431
NUMA node8 CPU(s): 216-223,312-319,408-415,504-511
NUMA node9 CPU(s): 144-151,240-247,336-343,432-439
NUMA node10 CPU(s): 152-159,248-255,344-351,440-447
NUMA node11 CPU(s): 160-167,256-263,352-359,448-455
Currently on this LPAR, the scheduler detects 2 levels of Numa and
created numa sched domains for all CPUs, but it finds a single DIE
domain consisting of all CPUs. Hence it deletes all numa sched
domains.
To address this, detect the shared processor and update topology soon
after CPUs are setup so that correct topology is updated just before
scheduler creates sched domain.
With the fix, dmesg reports:
numa: Node 0 CPUs: 0-7 32-39 64-71 96-103 176-183 272-279 368-375 464-471
numa: Node 1 CPUs: 8-15 40-47 72-79 104-111 184-191 280-287 376-383 472-479
numa: Node 2 CPUs: 16-23 48-55 80-87 112-119 192-199 288-295 384-391 480-487
numa: Node 3 CPUs: 24-31 56-63 88-95 120-127 200-207 296-303 392-399 488-495
numa: Node 4 CPUs: 208-215 304-311 400-407 496-503
numa: Node 5 CPUs: 168-175 264-271 360-367 456-463
numa: Node 6 CPUs: 128-135 224-231 320-327 416-423
numa: Node 7 CPUs: 136-143 232-239 328-335 424-431
numa: Node 8 CPUs: 216-223 312-319 408-415 504-511
numa: Node 9 CPUs: 144-151 240-247 336-343 432-439
numa: Node 10 CPUs: 152-159 248-255 344-351 440-447
numa: Node 11 CPUs: 160-167 256-263 352-359 448-455
and lscpu also reports:
Socket(s): 64
NUMA node(s): 12
Model: 2.0 (pvr 004d 0200)
Model name: POWER8 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 64K
L1i cache: 32K
NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471
NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479
NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487
NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495
NUMA node4 CPU(s): 208-215,304-311,400-407,496-503
NUMA node5 CPU(s): 168-175,264-271,360-367,456-463
NUMA node6 CPU(s): 128-135,224-231,320-327,416-423
NUMA node7 CPU(s): 136-143,232-239,328-335,424-431
NUMA node8 CPU(s): 216-223,312-319,408-415,504-511
NUMA node9 CPU(s): 144-151,240-247,336-343,432-439
NUMA node10 CPU(s): 152-159,248-255,344-351,440-447
NUMA node11 CPU(s): 160-167,256-263,352-359,448-455
Reported-by: Manjunatha H R <manjuhr1@in.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[mpe: Trim / format change log]
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge updates from Andrew Morton:
- a few misc things
- a few Y2038 fixes
- ntfs fixes
- arch/sh tweaks
- ocfs2 updates
- most of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
mm/hmm.c: remove unused variables align_start and align_end
fs/userfaultfd.c: remove redundant pointer uwq
mm, vmacache: hash addresses based on pmd
mm/list_lru: introduce list_lru_shrink_walk_irq()
mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()
mm/list_lru.c: move locking from __list_lru_walk_one() to its caller
mm/list_lru.c: use list_lru_walk_one() in list_lru_walk_node()
mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP
mm/sparse: delete old sparse_init and enable new one
mm/sparse: add new sparse_init_nid() and sparse_init()
mm/sparse: move buffer init/fini to the common place
mm/sparse: use the new sparse buffer functions in non-vmemmap
mm/sparse: abstract sparse buffer allocations
mm/hugetlb.c: don't zero 1GiB bootmem pages
mm, page_alloc: double zone's batchsize
mm/oom_kill.c: document oom_lock
mm/hugetlb: remove gigantic page support for HIGHMEM
mm, oom: remove sleep from under oom_lock
kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()
mm/cma: remove unsupported gfp_mask parameter from cma_alloc()
...
Use new return type vm_fault_t for fault handler. For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno. Once all instances are converted, vm_fault_t will become a
distinct type.
Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")
In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.
Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add statistics that show how memory is mapped within the kernel linear mapping.
This is similar to commit 37cd944c8d ("s390/pgtable: add mapping statistics")
We don't do this with Hash translation mode. Hash uses one size (mmu_linear_psize)
to map the kernel linear mapping and we print the linear psize during boot as
below.
"Page orders: linear mapping = 24, virtual = 16, io = 16, vmemmap = 24"
A sample output looks like:
DirectMap4k: 0 kB
DirectMap64k: 18432 kB
DirectMap2M: 1030144 kB
DirectMap1G: 11534336 kB
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The machine check code that flushes and restores bolted segments in
real mode belongs in mm/slb.c. This will also be used by pseries
machine check and idle code in future changes.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
‘type’ is only used when CONFIG_DEBUG_HIGHMEM is set. So add a possibly
unused tag to variable. Remove warning treated as error with W=1:
arch/powerpc/mm/highmem.c:59:6: error: variable ‘type’ set but not used [-Werror=unused-but-set-variable]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In Makefiles if we're testing a CONFIG_FOO symbol for equality with 'y'
we can instead just use ifdef. The latter reads easily, so convert to
it where possible.
Signed-off-by: Rodrigo R. Galvao <rosattig@linux.vnet.ibm.com>
Reviewed-by: Mauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The page table fragment allocator uses the main page refcount racily
with respect to speculative references. A customer observed a BUG due
to page table page refcount underflow in the fragment allocator. This
can be caused by the fragment allocator set_page_count stomping on a
speculative reference, and then the speculative failure handler
decrements the new reference, and the underflow eventually pops when
the page tables are freed.
Fix this by using a dedicated field in the struct page for the page
table fragment allocator.
Fixes: 5c1f6ee9a3 ("powerpc: Reduce PTE table memory wastage")
Cc: stable@vger.kernel.org # v3.10+
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The kernel page table caches are tied to init_mm, so there is no
more need for them after userspace is finished.
destroy_context() gets called when we drop the last reference for an
mm, which can be much later than the task exit due to other lazy mm
references to it. We can free the page table cache pages on task exit
because they only cache the userspace page tables and kernel threads
should not access user space addresses.
The mapping for kernel threads itself is maintained in init_mm and
page table cache for that is attached to init_mm.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Merge change log additions from Aneesh]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mmu_init_secondary() calls ppc44x_pin_tlb() which is marked __init,
leading to a warning:
The function mmu_init_secondary() references
the function __init ppc44x_pin_tlb().
There's no CPU hotplug support on 44x so mmu_init_secondary() will
only be called at boot. Therefore we should mark it as __init.
Signed-off-by: Alexey Spirkov <alexeis@astrosoft.ru>
[mpe: Flesh out change log details]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
asm/tlbflush.h is only needed for:
- using functions xxx_flush_tlb_xxx()
- using MMU_NO_CONTEXT
- including asm-generic/pgtable.h
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Files not using fixmap consts or functions don't need asm/fixmap.h
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
files not using feature fixup don't need asm/feature-fixups.h
files using feature fixup need asm/feature-fixups.h
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch moves ASM_CONST() and stringify_in_c() into
dedicated asm-const.h, then cleans all related inclusions.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: asm-compat.h should include asm-const.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We do this in some part. This patch make sure we always try to search
for hpte without holding lock and redo the compare with lock held once
match found.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When computing the starting slot number for a hash page table group we used
to do this
hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
Multiplying with 8 (HPTES_PER_GROUP) imply the last three bits are 0. Hence we
really don't need to clear then separately.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Applications need the ability to associate an address-range with some
key and latter revert to its initial default key. Pkey-0 comes close to
providing this function but falls short, because the current
implementation disallows applications to explicitly associate pkey-0 to
the address range.
Lets make pkey-0 less special and treat it almost like any other key.
Thus it can be explicitly associated with any address range, and can be
freed. This gives the application more flexibility and power. The
ability to free pkey-0 must be used responsibily, since pkey-0 is
associated with almost all address-range by default.
Even with this change pkey-0 continues to be slightly more special
from the following point of view.
(a) it is implicitly allocated.
(b) it is the default key assigned to any address-range.
(c) its permissions cannot be modified by userspace.
NOTE: (c) is specific to powerpc only. pkey-0 is associated by default
with all pages including kernel pages, and pkeys are also active in
kernel mode. If any permission is denied on pkey-0, the kernel running
in the context of the application will be unable to operate.
Tested on powerpc.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Drop #define PKEY_0 0 in favour of plain old 0]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
execute-only key is allocated dynamically. This is a problem. When a
thread implicitly creates an execute-only key, and resets the UAMOR
for that key, the UAMOR value does not percolate to all the other
threads. Any other thread may ignorantly change the permissions on the
key. This can cause the key to be not execute-only for that thread.
Preallocate the execute-only key and ensure that no thread can change
the permission of the key, by resetting the corresponding bit in
UAMOR.
Fixes: 5586cf61e1 ("powerpc: introduce execute-only pkey")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Total number of pkeys calculation is off by 1. Fix it.
Fixes: 4fb158f65a ("powerpc: track allocation status of all pkeys")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Key allocation and deallocation has the side effect of programming the
UAMOR/AMR/IAMR registers. This is wrong, since its the responsibility of
the application and not that of the kernel, to modify the permission on
the key.
Do not modify the pkey registers at key allocation/deallocation.
This patch also fixes a bug where a sys_pkey_free() resets the UAMOR
bits of the key, thus making its permissions unmodifiable from user
space. Later if the same key gets reallocated from a different thread
this thread will no longer be able to change the permissions on the key.
Fixes: cf43d3b264 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Deny all permissions on all keys, with some exceptions. pkey-0 must
allow all permissions, or else everything comes to a screaching halt.
Execute-only key must allow execute permission.
Fixes: cf43d3b264 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently in a multithreaded application, a key allocated by one
thread is not usable by other threads. By "not usable" we mean that
other threads are unable to change the access permissions for that
key for themselves.
When a new key is allocated in one thread, the corresponding UAMOR
bits for that thread get enabled, however the UAMOR bits for that key
for all other threads remain disabled.
Other threads have no way to set permissions on the key, and the
current default permissions are that read/write is enabled for all
keys, which means the key has no effect for other threads. Although
that may be the desired behaviour in some circumstances, having all
threads able to control their permissions for the key is more
flexible.
The current behaviour also differs from the x86 behaviour, which is
problematic for users.
To fix this, enable the UAMOR bits for all keys, at process
creation (in start_thread(), ie exec time). Since the contents of
UAMOR are inherited at fork, all threads are capable of modifying the
permissions on any key.
This is technically an ABI break on powerpc, but pkey support is fairly
new on powerpc and not widely used, and this brings us into
line with x86.
Fixes: cf43d3b264 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Tested-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Reword some of the changelog]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The HUGEPD_*_SHIFT macros are always defined to be PGDIR_SHIFT and
PUD_SHIFT, and have to have those values to work properly. They once used
to have different values, but that was really only because they were used
to mean different things in different contexts.
6fa50483 "powerpc/mm/hugetlb: initialize the pagetable cache correctly for
hugetlb" removed that double meaning, but left the now useless constants.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge in some commits we're sharing with the KVM tree.
I manually propagated the change from commit d3d4ffaae4
("powerpc/powernv/ioda2: Reduce upper limit for DMA window size") into
pci-ioda-tce.c.
Conflicts:
arch/powerpc/include/asm/cputable.h
arch/powerpc/platforms/powernv/pci-ioda.c
arch/powerpc/platforms/powernv/pci.h
A VM which has:
- a DMA capable device passed through to it (eg. network card);
- running a malicious kernel that ignores H_PUT_TCE failure;
- capability of using IOMMU pages bigger that physical pages
can create an IOMMU mapping that exposes (for example) 16MB of
the host physical memory to the device when only 64K was allocated to the VM.
The remaining 16MB - 64K will be some other content of host memory, possibly
including pages of the VM, but also pages of host kernel memory, host
programs or other VMs.
The attacking VM does not control the location of the page it can map,
and is only allowed to map as many pages as it has pages of RAM.
We already have a check in drivers/vfio/vfio_iommu_spapr_tce.c that
an IOMMU page is contained in the physical page so the PCI hardware won't
get access to unassigned host memory; however this check is missing in
the KVM fastpath (H_PUT_TCE accelerated code). We were lucky so far and
did not hit this yet as the very first time when the mapping happens
we do not have tbl::it_userspace allocated yet and fall back to
the userspace which in turn calls VFIO IOMMU driver, this fails and
the guest does not retry,
This stores the smallest preregistered page size in the preregistered
region descriptor and changes the mm_iommu_xxx API to check this against
the IOMMU page size.
This calculates maximum page size as a minimum of the natural region
alignment and compound page size. For the page shift this uses the shift
returned by find_linux_pte() which indicates how the page is mapped to
the current userspace - if the page is huge and this is not a zero, then
it is a leaf pte and the page is mapped within the range.
Fixes: 121f80ba68 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD1 was never a product. It is no longer supported by upstream
firmware, and it is not effectively supported in Linux due to lack of
testing.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Remove arch_make_huge_pte() entirely]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- introduce __diag_* macros and suppress -Wattribute-alias warnings from GCC 8
- fix stack protector test script for x86_64
- fix line number handling in Kconfig
- document that '#' starts a comment in Kconfig
- handle P_SYMBOL property in dump debugging of Kconfig
- correct help message of LD_DEAD_CODE_DATA_ELIMINATION
- fix occasional segmentation faults in Kconfig
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Merge tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- introduce __diag_* macros and suppress -Wattribute-alias warnings
from GCC 8
- fix stack protector test script for x86_64
- fix line number handling in Kconfig
- document that '#' starts a comment in Kconfig
- handle P_SYMBOL property in dump debugging of Kconfig
- correct help message of LD_DEAD_CODE_DATA_ELIMINATION
- fix occasional segmentation faults in Kconfig
* tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: loop boundary condition fix
kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION
kconfig: handle P_SYMBOL in print_symbol()
kconfig: document Kconfig source file comments
kconfig: fix line numbers for if-entries in menu tree
stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y
powerpc: Remove -Wattribute-alias pragmas
disable -Wattribute-alias warning for SYSCALL_DEFINEx()
kbuild: add macro for controlling warnings to linux/compiler.h
With SYSCALL_DEFINEx() disabling -Wattribute-alias generically, there's
no need to duplicate that for PowerPC syscalls.
This reverts commit 4155203739 ("powerpc: fix build failure by
disabling attribute-alias warning in pci_32") and commit 2479bfc9bc
("powerpc: Fix build by disabling attribute-alias warning for
SYSCALL_DEFINEx").
Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
With 4k page size for hugetlb we allocate hugepage directories from its on slab
cache. With patch 0c4d26802 ("powerpc/book3s64/mm: Simplify the rcu callback for page table free")
we missed to free these allocated hugepd tables.
Update pgtable_free to handle hugetlb hugepd directory table.
Fixes: 0c4d268029 ("powerpc/book3s64/mm: Simplify the rcu callback for page table free")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Add CONFIG_HUGETLB_PAGE guard to fix build break]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
