This patch adds a new documentation file explaining the DSCR support on
powerpc platforms. This explains DSCR related data structure, code paths
and also available user interfaces. Any further functional changes to
the DSCR support in the kernel should definitely update the
documentation here.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds some in-code documentation to the DSCR related code to
make it more readable without having any functional change to it.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PACA_DSCR offset macro tracks dscr_default element in the paca
structure. Better change the name of this macro to match that of the
data element it tracks. Makes the code more readable.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The process context switch code no longer uses dscr_default variable
from the sysfs.c file. The variable became unused when we started
storing the CPU specific DSCR value in the PACA structure instead.
This patch just removes this extern declaration. It was originally
added by the following commit.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently DSCR (Data Stream Control Register) can be accessed with
mfspr or mtspr instructions inside a thread via two different SPR
numbers. One being the user accessible problem state SPR number 0x03
and the other being the privilege state SPR number 0x11. All access
through the privilege state SPR number get emulated through illegal
instruction exception. Any access through the problem state SPR number
raises one facility unavailable exception which sets the thread based
dscr_inherit bit and enables DSCR facility through FSCR register thus
allowing direct access to DSCR without going through this exception in
the future. We set the thread.dscr_inherit bit whether the access was
with mfspr or mtspr instruction which is neither correct nor does it
match the behaviour through the instruction emulation code path driven
from privilege state SPR number. User currently observes two different
kind of behaviour when accessing the DSCR through these two SPR numbers.
This problem can be observed through these two test cases by replacing
the privilege state SPR number with the problem state SPR number.
(1) http://ozlabs.org/~anton/junkcode/dscr_default_test.c
(2) http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c
This patch fixes the problem by making sure that the behaviour visible
to the user remains the same irrespective of which SPR number is being
used. Inside facility unavailable exception, we check whether it was
cuased by a mfspr or a mtspr isntrucction. In case of mfspr instruction,
just emulate the instruction. In case of mtspr instruction, set the
thread based dscr_inherit bit and also enable the facility through FSCR.
All user SPR based mfspr instruction will be emulated till one user SPR
based mtspr has been executed.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we release the device, we should also invalidate the default context.
With this cxl_get_context() will return null after removal.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 28158cd "powerpc/eeh: Enhance pcibios_set_pcie_reset_state()"
introduced a fix for a problem where certain configurations could lead to
pci_reset_function() destroying the state of PCI devices other than the one
specified.
Unfortunately, the fix has a trivial bug - it calls pci_save_state() again,
when it should be calling pci_restore_state(). This corrects the problem.
Cc: Gavin Shan <gwshan@au1.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This change adds a char device to access the "PRD" (processor runtime
diagnostics) channel to OPAL firmware.
Includes contributions from Vaidyanathan Srinivasan, Neelesh Gupta &
Vishal Kulkarni.
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The (upcoming) opal-prd driver needs to access the message notifier and
xscom code, so add EXPORT_SYMBOL_GPL macros for these.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
opal_ipmi_init and opal_flash_init are equivalent, except for the
compatbile string. Merge these two into a common opal_pdev_init
function.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The opal_{get,set}_param calls return internal error codes which need
to be translated in errnos in Linux.
Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch does two things.
Firstly it presents the Accelerator Function Unit (AFUs) behind the POWER
Service Layer (PSL) as PCI devices on a virtual PCI Host Bridge (vPHB). This
in in addition to the PSL being a PCI device itself.
As part of the Coherent Accelerator Interface Architecture (CAIA) AFUs can
provide an AFU configuration. This AFU configuration recored is architected to
be the same as a PCI config space.
This patch sets discovers the AFU configuration records, provides AFU config
space read/write functions to these configuration records. It then enumerates
the PCI bus. It also hooks in PCI ops where appropriate. It also destroys the
vPHB when the physical card is removed.
Secondly, it add an in kernel API for AFU to use CXL. AFUs must present a
driver that firstly binds as a PCI device. This PCI device can then be using
to do CXL specific operations (that can't sit in the PCI ops) using this API.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The cxl kernel API will allow drivers other than cxl to export a file
descriptor which has the same userspace API. These file descriptors will be
able to be used against libcxl.
This exports those file ops for use by other drivers.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This moves the current include file from cxl.h -> cxl-base.h. This current
include file is used only to pass information between the base driver that
needs to be built into the kernel and the cxl module.
This is to make way for a new include/misc/cxl.h which will
contain just the kernel API for other driver to use
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cleanup Makefile by fixing line wrapping.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This reworks contexts lifetimes a bit to enable the kernel API where we may
want to reuse contexts. Here we will want to start and stop contexts without
freeing them.
Start context does the get pid & ctx so stop context will need to do the puts.
Here we move put pid & ctx to the detach context path which will become part of
the stop context path.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This updates AFU directed and dedicated modes for contexts attached to the
kernel.
The SR (similar to the MSR in the core) calculation is getting
quite complex and is duplicated in AFU directed and dedicated
modes. This patch also merges this SR calculation for these modes.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Split the afu_register_irqs() function so that different parts can
be useful elsewhere.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We only need to check the pid attached to this context for userspace contexts.
Kernel contexts can skip this check.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Export some symbols which will soon be used elsewhere in this driver.
Now they are global we rename them so to avoid collisions.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rename cxl_afu_reset() to __cxl_afu_reset() to we can reuse this function name
in the API.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rework __detach_context() and cxl_context_detach() so we can reuse them in the
kernel API.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add cookie parameter to afu_release_irqs() so that we can pass in a different
cookie than the context structure. This will be useful for other kernel
drivers that want to call this but get their own cookie back in the interrupt
handler.
Update all existing call sites.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that we parse the AFU Configuration record, dump some info on it when in
debug mode.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When probing we call pci_enable_device() but don't call pci_disable_device() on
fail. This causes refcounting issues in the PCI subsystem if a second driver
tries to bind to the same device.
This patch adds the pci_disable_device() to the probe error path. This error
path is hit when this cxl driver tries to bind to AFUs (on the vPHB) rather
than the physical device.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we expose AFUs as virtual PCI devices, they may look like the physical
CAPI PCI card. ie they may have the same vendor/device IDs.
We want to avoid these AFUs binding to this driver and any init this driver may
do.
Re-order card init to check the VSEC earlier before assigning BARs or
activating CXL. Also change the dev used in early prints as the adapter struct
may not be inited at this earlier stage.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that libcxl is public, let's document it.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a hook into the powerpc pci code for pci_disable_device() calls. The
generic code already provides a weak pcibios_disable_device() symbol, so we
just need to provide our own in powerpc and it'll get picked up.
This is passed directly to the phb controller ops, provided one exists.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently pnv_pci_shutdown() calls the PHB shutdown code for all PHBs in the
system. It dereferences the private_data assuming it's a powernv PHB, which
won't be the case when we have different PHB in the systems (like when we add
vPHBs for CXL).
This moves the shutdown hook to the pci_controller_ops and fixes the call site
to use that instead.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add cxl context pointer to archdata. We'll want to create one of these for cxl
PCI devices. Put them here until we can get a pci_dev specific private data.
This location was suggested by benh.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add release_device() hook to phb ops so we can clean up for specific phbs.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Export pcibios_claim_one_bus, pcibios_scan_phb and pcibios_alloc_controller.
These will be used by the CXL driver.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This fixes calculating the key bits (KP and KS) in the SLB VSID for kernel
mappings.
I'm not CCing this to stable as there are no uses of this currently.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The afu fd release path was identified as a significant bottleneck in
the overall performance of cxl. While an optimal AFU design would
minimise the need to close & reopen the AFU fd, it is not always
practical to avoid.
The bottleneck seems to be down to the call to synchronize_rcu(), which
will block until every other thread is guaranteed to be out of an RCU
critical section. Replace it with call_rcu() to free the context
structures later so we can return to the application sooner.
This reduces the time spent in the fd release path from 13356 usec to
13.3 usec - about a 100x speed up.
Reported-by: Fei K Chen <uchen@cn.ibm.com>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Export the "AFU Error Buffer" via sysfs attribute (afu_err_buf). AFU
error buffer is used by the AFU to report application specific
errors. The contents of this buffer are AFU specific and are intended to
be interpreted by the application interacting with the afu.
Suggested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Given a file descriptor on an afu device, libcxl currently uses the
major/minor number obtained from fstat on the fd to construct path to
the afu's sysfs directory. However it is possible that rather than using
one of the device in /dev/cxl, a kernel driver creates its own device
which export generic cxl interface to the userspace. This causes
problems with libcxl as it tries to use a wrong major/minor number to
construct the sysfs path and fail.
So this patch introduces a new ioctl called CXL_IOCTL_GET_AFU_ID on the
afu file descriptor to fetch the cxl_afu_id struct that holds the
card/offset-id and mode information. These info is then used by libcxl to
construct the correct path to the afu sysfs directory.
Testing:
- Build against pseries be/le configs
- Testing with corresponding libcxl changes to verify that it constructs
right sysfs path to the afu.
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These tests were merged in parallel to the install support, update them
now to use it.
This also adds cross compile support for the VPHN test which was missing
it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rather than continuing to maintain a copy of pseries_defconfig with
CONFIG_CPU_LITTLE_ENDIAN enabled, use the generic merge_config script
and use an le.config to enable little endian on top of pseries_defconfig
without the need for a duplicated _defconfig file.
This method will require less maintenance in the future and will ensure
that both 'defconfigs' are always in sync.
It is worth noting that the seemingly more simple approach of:
pseries_le_defconfig: pseries_defconfig
$(Q)$(MAKE) le.config
Will not work when building using O=builddir.
The obvious fix to that:
pseries_le_defconfig:
$(Q)$(MAKE) -f $(srctree)/Makefile pseries_defconfig le.config
Also does not work. This is because if we have for example:
config FOO
depends on CPU_BIG_ENDIAN
select BAR
Then BAR will be enabled by the first call to kconfig (via
pseries_defconfig), and then will remain enabled after we merge
le.config, even though FOO will have been turned off.
The solution is to ensure to only invoke the kconfig logic once, after
we have merged all the config fragments. This ensures nothing is
select'ed on that should then be disabled by the later merged configs.
This is done through the explicit call to make olddefconfig
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Reviewed-by: Samuel Mendoza-Jonas <sam.mj@au1.ibm.com>
[mpe: Massage change log, fix white space and use ARCH not SRCARCH]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These two configs should be identical with the exception of big or little
endian.
The big endian version has XMON_DEFAULT turned on while the little endian
has XMON_DEFAULT not set. It makes the most sense for defconfigs not to use
xmon by default, production systems should get back up as quickly as
possible, not sit in xmon.
In the event debugging is required, the option can be enabled or xmon=on
can be specified on commandline.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We need to use a trampoline when using LOAD_HANDLER(), because the
destination needs to be in the first 64kB. An absolute branch has
no such limitations, so just jump there.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We had some code to restore the LR in the relocatable system call path
back when we used the LR to do an indirect branch.
Commit 6a404806df ("powerpc: Avoid link stack corruption in MMU
on syscall entry path") changed this to use the CTR which is volatile
across system calls so does not need restoring.
Remove the stale comment and the restore of the LR.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we take a PMU exception or a software event we call
perf_read_regs(). This overloads regs->result with a boolean that
describes if we should use the sampled instruction address register
(SIAR) or the regs.
If the exception is in kernel, we start with the kernel regs and
backtrace through the kernel stack. At this point we switch to the
userspace regs and backtrace the user stack with perf_callchain_user().
Unfortunately these regs have not got the perf_read_regs() treatment,
so regs->result could be anything. If it is non zero,
perf_instruction_pointer() decides to use the SIAR, and we get issues
like this:
0.11% qemu-system-ppc [kernel.kallsyms] [k] _raw_spin_lock_irqsave
|
---_raw_spin_lock_irqsave
|
|--52.35%-- 0
| |
| |--46.39%-- __hrtimer_start_range_ns
| | kvmppc_run_core
| | kvmppc_vcpu_run_hv
| | kvmppc_vcpu_run
| | kvm_arch_vcpu_ioctl_run
| | kvm_vcpu_ioctl
| | do_vfs_ioctl
| | sys_ioctl
| | system_call
| | |
| | |--67.08%-- _raw_spin_lock_irqsave <--- hi mum
| | | |
| | | --100.00%-- 0x7e714
| | | 0x7e714
Notice the bogus _raw_spin_irqsave when we transition from kernel
(system_call) to userspace (0x7e714). We inserted what was in the SIAR.
Add a check in regs_use_siar() to check that the regs in question
are from a PMU exception. With this fix the backtrace makes sense:
0.47% qemu-system-ppc [kernel.vmlinux] [k] _raw_spin_lock_irqsave
|
---_raw_spin_lock_irqsave
|
|--53.83%-- 0
| |
| |--44.73%-- hrtimer_try_to_cancel
| | kvmppc_start_thread
| | kvmppc_run_core
| | kvmppc_vcpu_run_hv
| | kvmppc_vcpu_run
| | kvm_arch_vcpu_ioctl_run
| | kvm_vcpu_ioctl
| | do_vfs_ioctl
| | sys_ioctl
| | system_call
| | __ioctl
| | 0x7e714
| | 0x7e714
Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If both STRICT_MM_TYPECHECKS and DEBUG_PAGEALLOC are enabled, the code
in kernel_map_linear_page() is built, and so we fail with:
arch/powerpc/mm/hash_utils_64.c:1478:2:
error: incompatible type for argument 1 of 'htab_convert_pte_flags'
Fix it by using pgprot_val().
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Previously, dma_set_mask() on powernv was convoluted:
0) Call dma_set_mask() (a/p/kernel/dma.c)
1) In dma_set_mask(), ppc_md.dma_set_mask() exists, so call it.
2) On powernv, that function pointer is pnv_dma_set_mask().
In pnv_dma_set_mask(), the device is pci, so call pnv_pci_dma_set_mask().
3) In pnv_pci_dma_set_mask(), call pnv_phb->set_dma_mask() if it exists.
4) It only exists in the ioda case, where it points to
pnv_pci_ioda_dma_set_mask(), which is the final function.
So the call chain is:
dma_set_mask() ->
pnv_dma_set_mask() ->
pnv_pci_dma_set_mask() ->
pnv_pci_ioda_dma_set_mask()
Both ppc_md and pnv_phb function pointers are used.
Rip out the ppc_md call, pnv_dma_set_mask() and pnv_pci_dma_set_mask().
Instead:
0) Call dma_set_mask() (a/p/kernel/dma.c)
1) In dma_set_mask(), the device is pci, and pci_controller_ops.dma_set_mask()
exists, so call pci_controller_ops.dma_set_mask()
2) In the ioda case, that points to pnv_pci_ioda_dma_set_mask().
The new call chain is
dma_set_mask() ->
pnv_pci_ioda_dma_set_mask()
Now only the pci_controller_ops function pointer is used.
The fallback paths for p5ioc2 are the same.
Previously, pnv_pci_dma_set_mask() would find no pnv_phb->set_dma_mask()
function, to it would call __set_dma_mask().
Now, dma_set_mask() finds no ppc_md call or pci_controller_ops call,
so it calls __set_dma_mask().
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some systems only need to deal with DMA masks for PCI devices.
For these systems, we can avoid the need for a platform hook and
instead use a pci controller based hook.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove powernv generic PCI controller operations. Replace it with
controller ops for each of the two supported PHBs.
As an added bonus, make the two new structs const, which will help
guard against bugs such as the one introduced in 65ebf4b63
("powerpc/powernv: Move controller ops from ppc_md to controller_ops")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
