In PowerPC (pseries) a non-virtualized adapter will have 2 DMA windows -
2GB default and a larger Dynamic DMA Window (DDW). DDW is large enough to
map total RAM to a device.
During normal functioning of OS, since RAM is pre-mapped, 2GB default
window is not used. The only scenario it might get used is when buffers in
pmemory are mapped to the device for DMA.
As of today, during kdump, during early device discovery, pci_dma_find()
finds that the device has 2 DMA windows. It selects to use DDW. This is a
kdump path and DMA window is needed for IO to the device.
Although commit 09a3c1e461 ("powerpc/pseries/iommu: IOMMU table is not
initialized for kdump over SR-IOV") fixed an issue during kdump with SR-IOV
case, but this also made the kdump prefer DDW over the default DMA window
when both are present (dedicated adapter case). Since the DDW is fully
mapped by the previous kernel, iommu_table_clear() can free only
KDUMP_MIN_TCE_ENTRIES (2048) TCEs for use by kdump kernel.
This is not enough when the dump device is NVMe over Fibre Channel.
Because nvme-fc driver DMA-maps the cmds and resp IUs of every
pre-allocated request and each such mapping consumes roughly:
32 (IO queues, one per cpus = nr_cpus) *
64 (queue_depth, blk-mq kdump limit) *
2 (cmd+resp) = 4096
This is already double of what we have without counting admin queues and
lpfc driver's own allocations / mapping requirement. Hence this results
into iommu_alloc failures like -
lpfc 0153:70:00.0: iommu_alloc failed,
tbl 0000000034ebcf5e vaddr 00000000d814df0b npages 1
lpfc 0153:70:00.0: FCP Op failed - cmdiu dma mapping failed.
lpfc 0153:70:00.0: iommu_alloc failed,
tbl 0000000034ebcf5e vaddr 000000009779e4d2 npages 1
lpfc 0153:70:00.0: FCP Op failed - cmdiu dma mapping failed.
iommu_map_phys+0x1c4/0x1f0 (unreliable)
dma_iommu_map_phys+0x54/0xa0
dma_map_phys+0x3f8/0x590
__nvme_fc_init_request+0x110/0x300 [nvme_fc]
nvme_fc_init_request+0x60/0xb8 [nvme_fc]
blk_mq_alloc_map_and_rqs+0x388/0x510
blk_mq_alloc_tag_set+0x2a4/0x5f0
nvme_alloc_io_tag_set+0xe0/0x1e0 [nvme_core]
nvme_fc_connect_ctrl_work+0x85c/0xdac [nvme_fc]
process_one_work+0x1e4/0x5a0
worker_thread+0x1ec/0x3e0
Increasing the number of free TCE entries in iommu_table_clear() will
increase the probability of hitting EEH since there could still be some
active IOs from the previous life of the kernel.
Hence this patch partially reverts the previous fixes commit and
switches the kdump's default back to 2GB default DMA window instead of
DDW window. This window will mostly be empty. Or, could be slightly used
if buffers in pmemory were mapped for IO.
Fixes: 09a3c1e461 ("powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV")
Cc: stable@vger.kernel.org
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803224029.60538-1-gbatra@linux.ibm.com
Before commit e3c4ff6d8c ("EDAC: Remove EDAC_MM_EDAC") EDAC_MM_EDAC
selected RAS, after that commit, EDAC depends on RAS, but nobody enables
it. Enable it in the config again.
Fixes: e3c4ff6d8c ("EDAC: Remove EDAC_MM_EDAC")
Signed-off-by: Michael Walle <mwalle@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260730105546.3658570-1-mwalle@kernel.org
Add documentation for the KVM_PPC_GET_COMPAT_CAPS ioctl to the KVM API
documentation.
The ioctl exposes host processor compatibility modes supported for
nested KVM guests on PowerPC systems. The documentation covers error
code descriptions including E2BIG for forward compatibility,
KVM_PPC_COMPAT_CAPS_SIZE_VER0 as the minimum size floor, the rationale
for rejecting non-zero reserved fields to prevent ABI ambiguity, bit
numbering clarification for IBM MSB-0 convention, and KVM-specific
capability bit constants.
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-5-amachhiw@linux.ibm.com
Currently, when booting a compatibility-mode KVM guest (L1) on a PowerNV
hypervisor (L0), the guest runs with the expected processor
compatibility level. However, when booting a nested KVM guest (L2)
inside the L1, QEMU derives the CPU model from the raw host PVR and
attempts to run the nested guest at that level, instead of honoring the
compatibility mode of the L1.
Extend host CPU compatibility capability reporting to support nested
virtualization on PowerNV systems (PAPR nested API v1).
For nested API v2 (PowerVM), compatibility capabilities are served from
the cached nested_capabilities value (populated at module init via
kvmhv_nested_init() using the H_GUEST_GET_CAPABILITIES hcall). This
information is not available on PowerNV systems.
For nested API v1, derive the compatibility capabilities from the L1
guest by reading the "cpu-version" property from the device tree, which
reflects the effective (logical) processor compatibility level. Map this
value to the corresponding compatibility capability bitmap using
KVM-specific constants.
The mapping is cumulative: a system running at a given compatibility
level is assumed to also support older generations down the supported
chain. Note that unlike KVM on PowerVM (nested API v2), KVM on PowerNV
currently does not strictly enforce older generation compatibility modes
for nested guests - the reported capabilities reflect what the host CPU
can present, not what the hypervisor independently validates.
Introduce a helper kvmppc_map_compat_capabilities() to translate CPU
version values into KVM_PPC_COMPAT_CAP bits using a fallthrough switch,
and integrate it into kvmppc_get_compat_caps(). The implementation
applies masking to ensure only supported processor modes are exposed.
This allows userspace to query host CPU compatibility modes on both
KVM on PowerVM and on PowerNV platforms via the KVM_PPC_GET_COMPAT_CAPS
ioctl.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-4-amachhiw@linux.ibm.com
On POWER systems, the host CPU may run in a compatibility mode (e.g., a
Power11 processor operating in Power10 compatibility mode). In such
cases, the effective CPU level exposed to guests differs from the
physical processor generation.
When running nested KVM guests, QEMU derives the host CPU type using
mfpvr(), which reflects the physical processor version. This can result
in a mismatch between the CPU model selected by QEMU and the
compatibility mode enforced by the host, leading to guest boot failures.
For example, booting a nested guest on a Power11 LPAR configured in
Power10 compatibility mode fails with:
KVM-NESTEDv2: couldn't set guest wide elements
[..KVM reg dump..]
This occurs because QEMU selects a CPU model corresponding to the
physical processor (via mfpvr()), while the host operates in a lower
compatibility mode. As a result, KVM rejects the requested compatibility
level during guest initialization.
On pseries nestedv2 systems, add support for retrieving host CPU
compatibility capabilities for nested guests on PowerVM. The capability
bitmap reflects the processor modes negotiated between the Power
hypervisor (L0) and the host partition (L1) via the
H_GUEST_GET_CAPABILITIES hcall, but is retrieved from the cached
nested_capabilities value populated during module initialization,
avoiding repeated hypervisor calls. A WARN_ON_ONCE() flags the
unexpected case where nested_capabilities is zero on a nestedv2 system.
The implementation defines KVM-specific capability constants
(KVM_PPC_COMPAT_CAP_POWER9/10/11), masks unsupported bits, and exposes
the result through the KVM_PPC_GET_COMPAT_CAPS ioctl.
Hook the implementation into the Book3S HV kvmppc_ops so that it can be
invoked by the generic KVM ioctl handling code.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-3-amachhiw@linux.ibm.com
Introduce a new capability and ioctl to expose CPU compatibility modes
supported by the host processor for nested guests.
On IBM POWER systems, newer processor generations (N) can operate in
compatibility modes corresponding to earlier generations, like (N-1) and
(N-2). This is particularly relevant for nested virtualization, where
nested KVM guests may need to run with a specific processor compatibility
level.
Introduce KVM_CAP_PPC_COMPAT_CAPS capability and the corresponding
KVM_PPC_GET_COMPAT_CAPS vm ioctl. The ioctl returns a bitmap describing
the compatibility modes supported by the host in respective bit numbers,
allowing userspace (e.g., QEMU) to select an appropriate compatibility
level when configuring nested KVM guests.
The ioctl handling is added in kvm_arch_vm_ioctl() and retrieves host
CPU compatibility capabilities via a PowerPC-specific backend
implementation when available.
The struct kvm_ppc_compat_caps places the 'size' field first so it can
be read alone via get_user() before copy_struct_from_user() is called,
avoiding pointer arithmetic to locate the size field.
The ioctl is defined using _IO so the ioctl number remains stable even if
the struct grows in future versions. It uses copy_struct_from_user() and
copy_struct_to_user() to provide forward- and backward-compatible
extensibility: older userspace passing a smaller struct to a newer kernel
gets zero-padded trailing fields. Newer userspace passing a larger struct to
an older kernel (usize > ksize) succeeds if trailing bytes are zero (the
kernel reports back min(usize, ksize) as the filled size); if trailing bytes
are non-zero, the kernel writes back ksize into host_caps.size and returns
-E2BIG so userspace can retry with the correct size.
KVM_PPC_COMPAT_CAPS_SIZE_VER0 is defined as a frozen integer constant
(24) marking the size of the initial struct version, used as the
minimum floor for size field validation, similar to other versioned
struct interfaces in the kernel.
The 'flags' field is reserved for future use. The kernel rejects any
call where flags is non-zero with -EINVAL, preventing garbage values
from being baked into ABI permanently.
The ioctl returns appropriate error codes: E2BIG if usize exceeds
PAGE_SIZE, or if new userspace provides a larger struct with non-zero
trailing bytes (with ksize written back into host_caps.size for the
retry); EINVAL for an invalid size or non-zero reserved fields; EFAULT
for failed copy operations; and ENOTTY if the backend doesn't implement
get_compat_caps.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-2-amachhiw@linux.ibm.com
Replace devm_kasprintf() with dev_name() for the chip label. dev_name()
returns a stable pointer to the device name, so the separate allocation
and -ENOMEM check can be dropped.
Using dev_name() seems to be common for GPIO labels.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-9-rosenp@gmail.com
Shifting a 32-bit unsigned integer by 32 or more places is undefined
behavior in C. GPIO_MASK2 computes its shift amount as (gpio) * 2, and
for pins 16-31 in the OSRH/TSRH bank this yields shifts of 32-62.
While this happens to work on PowerPC because slw masks the shift count
to the low 5 bits, compilers performing value-range propagation may
assume the else branch is unreachable and optimize it away, or may
evaluate the shift as zero on other architectures via COMPILE_TEST.
Mask gpio to the 16-pin bank index so the shift stays within [0, 30].
The registers are banked (OSRL/TSRL for gpio 0-15, OSRH/TSRH for
gpio 16-31) with an identical 2-bit-per-pin layout from MSB to LSB,
so masking to the within-bank index preserves the intended behavior.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-8-rosenp@gmail.com
Replace PPC-specific clrbits32()/setbits32() with local helpers using
ioread32be()/iowrite32be() which are equivalent on PPC since commit
894fa235eb ("powerpc: inline iomap accessors").
Add COMPILE_TEST as a result to increase compile coverage.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-7-rosenp@gmail.com
Use gpio_generic_chip_init() to set up the PPC44x GPIO chip
instead of open-coding the basic get, set, locking and state handling.
Keep the PPC44x-specific direction callbacks because they still need to
program ODR and the OSR/TSR registers around the generic data and
direction registers.
Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-6-rosenp@gmail.com
Map the PPC44x GPIO register block through the platform device
resource instead of reparsing the firmware node directly.
The GPIO node now probes as a platform device, so use the
platform helper to keep resource handling aligned with the converted
driver model and to report mapping failures with the platform device
context.
Move ioremap up in order to avoid doing extra work in case of
-EPROBE_DEFER.
Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-5-rosenp@gmail.com
Replace the open-coded arch initcall registration with
module_platform_driver(). The initcall level changes from
arch_initcall to device_initcall, which is safe since the
driver no longer needs architecture-specific ordering.
Added MODULE info as a result, otherwise these warnings appear
ERROR: modpost: missing MODULE_LICENSE() in drivers/gpio/gpio-ppc4xx.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/gpio/gpio-ppc4xx.o
Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-4-rosenp@gmail.com
The kernel lost support for 4xx platforms and now only supports 44x.
Since this driver is being moved to drivers/gpio/ , take the opportunity
to modernize the name.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-3-rosenp@gmail.com
Move the ppc4xx gpio driver out of arch/powerpc/platforms/44x/ into
drivers/gpio/gpio-ppc44x.c. The driver has no architecture-specific
dependencies and follows the same pattern as other PowerPC GPIO
drivers already in drivers/gpio/ (e.g. gpio-mpc8xxx, gpio-mpc5200).
- Renamed Kconfig symbol from PPC4xx_GPIO to GPIO_PPC44X
- Updated ppc44x_defconfig and warp_defconfig to use the new symbol
- Marked the new option as tristate (was bool) since the driver
supports module build via module_platform_driver()
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-2-rosenp@gmail.com
Replace min_t() with the simpler min() macro since the values are
unsigned and compatible.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260804112011.59416-4-thorsten.blum@linux.dev
Replace min_t() with the simpler min() macro since the values are
unsigned and compatible.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260804112011.59416-3-thorsten.blum@linux.dev
Base enablement patch to register performance monitoring hardware
support for power12. Patch introduce the raw event encoding format,
defines the supported list of events, config fields for the event
attributes and their corresponding bit values which are exported via
sysfs.
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-5-mahesh@linux.ibm.com
PVR value of 0x0f000008 means we are arch v3.2 compliant (i.e.
Power12). This is used by phyp and kvm when booting as a pseries guest
to detect the presence of new Power12 features and to enable the
appropriate hwcap and facility bits.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-4-mahesh@linux.ibm.com
Current Power system firmware caps the PVR list array size at 16 entries
during CAS (Client Architecture Support) negotiation. Passing more than
capped size to older firmware could cause an undefined behaviour and
breaks compatibility.
Future Power system firmware releases will lift this restriction and
support greater than 16 array entries.
Ensure that when running on Power11 or below hardware, the number
of PVR entries passed during CAS negotiation does not exceed the
firmware-imposed limit of 16.
In prom_send_capabilities(), compute start_index to skip the oldest
leading pvrs[] entries when running on Power11 or below hardware, so
that the pointer passed to ibm,client-architecture-support points to
ibm_architecture_vec.pvrs[start_index], presenting exactly 16 entries to
firmware.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-2-mahesh@linux.ibm.com
Sashiko reported that the irqchip index is not validated for PowerPC.
Add validation and reject out-of-range irqchip indexes to avoid indexing
past the routing table's chip array.
Fixes: de9ba2f363 ("KVM: PPC: Support irq routing and irqfd for in-kernel MPIC")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/kvm/20260525051714.485D51F000E9@smtp.kernel.org/
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Yanfei Xu <yanfei.xu@bytedance.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
The value loaded into r0 in copy_and_flush() represents the number of
8-byte words processed between cache synchronization operations.
The existing comment refers to cache line size, which can make it appear
that the value is a cache line size in bytes rather than a loop count.
Clarify the comment to explain that the loop processes 8 words (64 bytes)
per cache synchronization iteration, and that increasing the value would
skip cache maintenance for intermediate cache lines.
This is a comment-only change with no functional impact.
Signed-off-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Aditya Gupta <adityag@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260706082708.43918-1-nikhilks@linux.ibm.com
In CONFIG_PPC_KERNEL_PCREL mode, r2 is no longer reserved for the TOC
pointer and is available as a caller-saved register [0].
Both call_do_irq() and call_do_softirq() use inline assembly to call
functions with stack switching, but fail to list r2 in their clobber
lists. This causes the compiler to assume r2 is preserved across these
calls, leading to register corruption when the called functions
(__do_irq and __do_softirq) clobber r2.
As a result of this kernel crash during interrupt handling is seen and
the kernel fails to boot:
BUG: Unable to handle kernel data access on write at 0xc000000404697638
Faulting instruction address: 0xc0000000000181ec
Oops: Kernel access of bad area, sig: 11 [#1]
NIP [c0000000000181ec] __do_IRQ+0x6c/0xc0
With older GCC, the compiler would conservatively allocate
callee-saved registers (like r31) for values spanning function calls,
accidentally avoiding the bug:
<__do_IRQ>:
00 00 00 60 nop
a6 02 08 7c mflr r0
f8 ff e1 fb std r31,-8(r1)
f0 ff c1 fb std r30,-16(r1)
2d 03 10 06 pla r31,53297316
...
3d e8 ff 4b bl c0000000000165ac <__do_irq>
00 00 21 e8 ld r1,0(r1)
28 00 4d e9 ld r10,40(r13)
40 00 21 38 addi r1,r1,64
2a f9 aa 7f stdx r29,r10,r31
With newer GCC 14, the compiler uses r2 for such values, exposing the
missing clobber specification:
<__do_IRQ>:
00 00 00 60 nop
a6 02 08 7c mflr r0
f0 ff c1 fb std r30,-16(r1)
f8 ff e1 fb std r31,-8(r1)
29 02 10 06 pla r2,36252592 # c0000000022aadc0 <__irq_regs>
...
85 dc ff 4b bl c000000000015ee0 <__do_irq>
00 00 21 e8 ld r1,0(r1)
28 00 2d e9 ld r9,40(r13)
30 00 21 38 addi r1,r1,48
2a 11 c9 7f stdx r30,r9,r2
Fix this by adding r2 to the clobber list for both call_do_irq() and
call_do_softirq() when CONFIG_PPC_KERNEL_PCREL is enabled.
[0]: https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg313226.html
Fixes: 7e3a68be42 ("powerpc/64: vmlinux support building with PCREL addresing")
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/10fc2cda485cd22e209a31d786bed1984bdf3982.1785732393.git.skb99@linux.ibm.com
With CONFIG_PPC_KERNEL_PCREL enabled, calling bpf_check_timed_may_goto()
using a bl instruction results in a link-time failure:
arch/powerpc/net/bpf_timed_may_goto.o: in function `arch_bpf_timed_may_goto':
(.text+0x28): call to `bpf_check_timed_may_goto' lacks nop, can't restore toc
Use CFUNC() macro instead of direct 'bl' to properly annotate the call
to bpf_check_timed_may_goto(). On PCREL builds, CFUNC() expands to
'bl name@notoc', informing the linker that TOC restoration is not
needed, avoiding the "lacks nop, can't restore toc" linker error.
Fixes: b55b6b9ad7 ("powerpc64/bpf: Add powerpc64 JIT support for timed may_goto")
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/f75e5aa911afb984a94c0e85d58b1be5fb428548.1785387718.git.skb99@linux.ibm.com
With CONFIG_PPC_KERNEL_PCREL enabled, build breaks with below error:
CC mm/dmapool.o
CC fs/readdir.o
arch/powerpc/net/bpf_jit_comp64.c: In function 'bpf_jit_emit_func_call_rel':
arch/powerpc/net/bpf_jit_comp64.c:475:13: error: unused variable 'ret' [-Werror=unused-variable]
475 | int ret;
| ^~~
Commit b55b6b9ad7 ("powerpc64/bpf: Add powerpc64 JIT support for timed may_goto")
introduced "ret" at function scope, but it is only used within its
respective conditional blocks. Same holds true for reladdr. Move both
variable declarations to the scopes where they are actually used:
"reladdr" to the CONFIG_PPC_KERNEL_PCREL block and "ret" to the non-PCREL
else block.
Fixes: b55b6b9ad7 ("powerpc64/bpf: Add powerpc64 JIT support for timed may_goto")
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/e8e582fb425db165a72f00e3337cdf4c6ae383ad.1785387718.git.skb99@linux.ibm.com
After enabling GENERIC_ENTRY on PowerPC, syscall_enter_from_user_mode()
returns -1 as a sentinel to signal that seccomp or ptrace has intercepted
the syscall and already set a return value via syscall_set_return_value().
system_call_exception() was not handling this sentinel, and since -1UL
is >= NR_syscalls, the code fell into the out-of-range path and returned
-ENOSYS, overwriting the errno already placed in regs->gpr[3].
The naive fix of checking r0 == -1L before the NR_syscalls bounds check
is ambiguous: a user legitimately calling syscall(-1) also produces r0 ==
-1L, and a tracer intercepting such a call would have its injected return
value silently discarded.
Fix this by introducing a thread flag that is set whenever
syscall_set_return_value() explicitly updates the return value. In
system_call_exception(), check and clear this flag before dispatching
the syscall, and return the preset value directly when it is present.
This ensures that an explicitly supplied return value always suppresses
syscall execution, regardless of the syscall number.
This handles all seccomp actions correctly:
- SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE (no tracer), SECCOMP_RET_USER_NOTIF:
all call syscall_set_return_value(), flag is set, injected value returned.
- SECCOMP_RET_TRAP, SECCOMP_RET_KILL: call syscall_rollback() and deliver
a signal; flag is not set, but the process is dying so the return value
is irrelevant.
The fix covers both ppc32 and ppc64 with no #ifdefs.
Fixes: bee25f97ad ("powerpc: Enable GENERIC_ENTRY feature")
Reported-by: Michal Suchánek <msuchanek@suse.de>
Closes: https://lore.kernel.org/all/ajpp-_XnbF3UTM_E@kunlun.suse.cz/
Tested-by: Michal Suchánek <msuchanek@suse.de>
Reviewed-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260731081521.1852133-1-mkchauras@gmail.com
On pseries LPAR systems, watchdog timers configured from userspace can
remain active after a kernel panic. When a panic triggers kdump, the
crashing kernel jumps directly to the kdump kernel without stopping
active watchdogs. As a result, the watchdogs remain active after the
kdump kernel starts.
If dump capture takes longer than the watchdog timeout, PHYP resets the
LPAR before the dump is fully captured, causing dump capture to fail.
Fix this by issuing the `H_WATCHDOG` hcall during the crash shutdown
sequence to stop all active watchdogs before booting the kdump kernel.
Cc: stable@vger.kernel.org
Fixes: 69472ffa65 ("watchdog/pseries-wdt: initial support for H_WATCHDOG-based watchdog timers")
Reported-by: Mahesh Kumar G <mahe657@linux.ibm.com>
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-4-sourabhjain@linux.ibm.com
The pseries watchdog initialization registers the pseries-wdt platform
device using platform_device_register_simple(), but currently ignores
its return value.
Check the returned pointer for errors, log a descriptive error message
when registration fails, and propagate the failure code to the caller.
This avoids silently ignoring platform device registration failures.
Cc: stable@vger.kernel.org
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-3-sourabhjain@linux.ibm.com
The H_WATCHDOG input and output definitions are currently local to the
pseries watchdog driver. The next patch in this series also needs these
definitions to issue H_WATCHDOG hypercalls outside the watchdog driver.
Move the H_WATCHDOG definitions to a new common header,
asm/papr-watchdog.h, so they can be shared without duplicating the
PAPR watchdog definitions.
No functional changes.
Cc: stable@vger.kernel.org
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-2-sourabhjain@linux.ibm.com
On IBM POWER systems, newer processor generations can operate in
compatibility modes corresponding to earlier generations. This becomes
relevant for nested virtualization, where nested KVM guests may need to
run with a specific processor compatibility level.
Currently, when running a nested KVM guest (L2) inside a Power11 pSeries
logical partition (L1) booted in Power10 compatibility mode, the guest
fails to boot while setting 'arch_compat'. This happens because the CPU
class is derived from the hardware PVR (via mfspr()), which reflects the
physical processor generation (Power11), rather than the effective
compatibility mode (Power10).
As a result, userspace may request a Power11 arch_compat for the L2
guest. However, the L1 partition, running in Power10 compatibility, has
only negotiated support up to Power10 with the Power Hypervisor (L0).
When H_GUEST_SET_STATE is invoked with a Power11 Logical PVR, the
hypervisor rejects the request, leading to a late guest boot failure:
KVM-NESTEDv2: couldn't set guest wide elements
[..KVM reg dump..]
This situation should be detected earlier and rejected by KVM. Without
proper validation, if userspace ignores the error, the guest may continue
to boot in Power11 raw mode on a Power10 compatibility host, which should
not be allowed.
Introduce a validation mechanism that detects unsupported arch_compat
values early in the guest initialization path. When an unsupported
arch_compat is requested (e.g., Power11 on a Power10 compatibility mode
host), kvmppc_set_arch_compat() uses cpu_has_feature(CPU_FTR_P11_PVR) to
detect the mismatch and sets arch_compat to PVR_ARCH_INVALID (0xffffffff).
This sentinel value is architecturally safe: PAPR specifies that valid
logical PVR values must have 0x0f as the first byte, ensuring 0xffffffff
lies permanently outside the specification-defined range. Setting this
value triggers kvmppc_sanity_check() to mark the vCPU as invalid by
setting vcpu->arch.sane to false. On the next vCPU run, kvmppc_vcpu_run_hv()
checks this flag and returns -EINVAL, preventing the guest from running
with an invalid processor compatibility configuration.
With this, when a Power11 arch_compat is requested on a Power10
compatibility mode host, the guest fails early during boot with:
error: kvm run failed Invalid argument
This provides a much clearer failure mode compared to the previous
behavior where the guest could boot in Power11 raw mode (if userspace
ignored the error) or fail late during H_GUEST_SET_STATE.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Acked-by: Gautam Menghani <gautam@linux.ibm.com>
Cc: stable@vger.kernel.org # v6.13+
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260714175432.86388-1-amachhiw@linux.ibm.com
smp_muxed_ipi_message_pass() calls smp_ops->cause_ipi() without
checking whether it has been set.
On platforms using muxed IPI (e.g. powernv/pseries), smp_ops->cause_ipi
is initialized to NULL in the static smp_ops and only assigned during
the platform smp_probe() handler. If the IPI subsystem fails to
initialize -- for example when xive_init_ipis() fails and
xive_smp_probe() returns an error -- the probe handler returns early
and cause_ipi is never set. Any subsequent IPI send (e.g.
arch_smp_send_reschedule()) would dereference the NULL pointer.
Add a NULL check to avoid the crash in that situation.
Fixes: 23d72bfd8f ("powerpc: Consolidate ipi message mux and demux")
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-6-gouhao@uniontech.com
xive_smp_probe() currently assigns smp_ops->cause_ipi = xive_cause_ipi
before calling xive_init_ipis() and xive_setup_cpu_ipi(). If either
call fails, the platform probe handler returns early but cause_ipi
remains pointing to xive_cause_ipi -- which accesses per-cpu IPI data
(xc->ipi_data) that was never properly initialized, leading to
a WARN and a crash.
Move the cause_ipi assignment to after both calls succeed, so that
smp_ops->cause_ipi is only set when the IPI subsystem is fully
initialized.
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Suggested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-5-gouhao@uniontech.com
When xive_init_ipis() fails (e.g. irq_domain_alloc_irqs() fails),
the error path frees the global xive_ipis array. However,
xive_smp_probe() previously ignored this failure and proceeded to
call xive_setup_cpu_ipi(), which dereferences the already-freed
xive_ipis pointer -- a use-after-free.
Now that xive_smp_probe() returns int (previous patch), propagate
the error from xive_init_ipis() and xive_setup_cpu_ipi() through
xive_smp_probe(). Check the return value in both pnv_smp_probe()
and pSeries_smp_probe() so that IPI setup is aborted cleanly on
failure, avoiding the use-after-free.
Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Fixes: cbc06f051c ("powerpc/xive: Do not skip CPU-less nodes when creating the IPIs")
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-4-gouhao@uniontech.com
xive_smp_probe() calls xive_init_ipis() which can fail, but its
return value is currently ignored. Change xive_smp_probe() to
return int so that errors can be propagated to callers.
This is a preparatory patch for the next one.
No functional change yet; the return value is always 0 at this point.
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-3-gouhao@uniontech.com
__GFP_NOFAIL should not be used in new code [1]. xive_init_ipis()
allocates the xive_ipis array with __GFP_NOFAIL, which makes the
subsequent NULL check unreachable dead code.
Remove __GFP_NOFAIL so the allocation can fail, and make all xive_ipis
access paths NULL-safe:
- Return XIVE_BAD_IRQ from xive_ipi_cpu_to_irq() when xive_ipis is NULL.
- Set xive_ipis to NULL after kfree() in the error path to prevent
use-after-free.
- Guard xive_setup_cpu_ipi() and xive_cleanup_cpu_ipi() against
xive_ipi_irq == XIVE_BAD_IRQ to avoid dereferencing an uninitialized
or already-freed xive_ipis array.
No functional change when allocation succeeds.
Link: https://lore.kernel.org/all/20260725202632.dcb325658896a470df91cf57@linux-foundation.org/ [1]
Fixes: 7dcc37b3ef ("powerpc/xive: Map one IPI interrupt per node")
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Cédric Le Goater <clg@kaod.org>
Suggested-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-2-gouhao@uniontech.com
Sashiko AI review pointed out the following issue.
The __merge_memory_ranges() function incorrectly handles overlapping
memory ranges when merging them. Although sort_memory_ranges() sorts all
ranges by their start address in ascending order beforehand, the merge
logic remains defective in two ways:
1. It compares the current range's start against the previous element (i-1)
instead of the running target index (idx)
2. It unconditionally overwrites 'ranges[idx].end' with 'ranges[i].end'.
This logic flaw leads to critical memory truncation when a larger memory
range completely subsumes subsequent smaller ranges.
For example, consider a sorted input array with three ranges:
Range A (idx=0): [0x1000 - 0x9000]
Range B (i=1): [0x2000 - 0x5000] (completely inside Range A)
Range C (i=2): [0x6000 - 0x8000] (completely inside Range A)
1. When i=1 (Range B):
ranges[1].start (0x2000) <= ranges[0].end + 1 (0x9001) is TRUE.
The code executes: ranges[0].end = ranges[1].end, which erroneously
shrinks Range A's end from 0x9000 down to 0x5000.
2. When i=2 (Range C):
ranges[2].start (0x6000) <= ranges[1].end + 1 (0x5001) is FALSE.
The code falls into the else block, creating a broken new range.
As a result, valid memory fragments [0x5001 - 0x5fff] and [0x8001 - 0x9000]
are completely lost from the kexec exclude lists, potentially allowing
the crash kernel to overwrite active memory, causing data corruption
or crashes.
Fix this by ensuring the start of the current range is compared against the
end of the active merged range (idx), and use max() to safely prevent the
outer boundary from being truncated.
Cc: stable@vger.kernel.org
Fixes: 180adfc532 ("powerpc/kexec_file: Add helper functions for getting memory ranges")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260729012948.2797865-4-ruanjinjie@huawei.com
A static Sashiko AI review identified a potential NULL pointer
dereference in kexec_extra_fdt_size_ppc64().
On platforms without any reserved memory regions,
get_reserved_memory_ranges() can return 0 while leaving 'rmem'
unallocated as NULL. Passing it directly leads to a kernel panic when
evaluating 'rmem->nr_ranges'.
Add a NULL check for 'rmem' to prevent this crash.
Cc: stable@vger.kernel.org
Fixes: 0d3ff06733 ("powerpc/kexec_file: fix extra size calculation for kexec FDT")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260729012948.2797865-3-ruanjinjie@huawei.com
In get_crash_memory_ranges(), if crash_exclude_mem_range() failed
after realloc_mem_ranges() has successfully allocated the cmem
memory, it just returns an error but leaves cmem pointing to
the allocated memory, nor is it freed in the caller
update_crash_elfcorehdr(), which cause a memory leak, goto out
to free the cmem.
Fixes: 849599b702 ("powerpc/crash: add crash memory hotplug support")
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260729012948.2797865-2-ruanjinjie@huawei.com
The PPC4xx GPIO driver stopped assigning an explicit parent
to the gpio_chip when it moved away from of_mm_gpiochip_add_data().
Restore that association from the platform device so OF GPIO lookup
can match phandles to the registered gpiochip.
Tested on: Cisco MX60W. No more probe deferral.
Assisted-by: Codex:GPT-5.5
Fixes: 1044dbaf2a ("powerpc/44x: Change GPIO driver to a proper platform driver")
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260517063754.21819-1-rosenp@gmail.com
The lack of get_direction() callback in this driver causes GPIOLIB to
emit a warning. Implement it.
Fixes: e623c4303e ("gpiolib: sanitize the return value of gpio_chip::get_direction()")
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/c6eb70aa0e1ba6e15f947c827006aa79edace05c.1785318836.git.chleroy@kernel.org
Include asm-generic/serial.h and use the generic BASE_BAUD definition
instead of redefining it.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260729223807.570178-3-thorsten.blum@linux.dev
There have been no sprintf() callers in the boot wrapper since commit
e275e023aa ("powerpc/44x: Warp patches for the new NDFC driver").
Remove the function definition and declaration.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260724172200.208722-2-thorsten.blum@linux.dev
Check only the first byte instead of scanning the entire string with
strlen().
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260721155346.121975-4-thorsten.blum@linux.dev
Check only the first byte instead of scanning the entire string with
strlen().
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260721155346.121975-3-thorsten.blum@linux.dev
Use cpu_relax() to wait for the execution status SPE_EX_STATE_EXECUTED.
Drop the comments while at it.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260720231153.116827-2-thorsten.blum@linux.dev
Check only the first byte instead of scanning the entire string with
strlen(). While at it, keep dt_cpu_name static, but move it into
dt_cpu_ftrs_scan_callback(), where it is assigned.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260701114428.818748-3-thorsten.blum@linux.dev
Now that struct rtas_error_log uses a flexible array member for the
extended log buffer, use struct_size() to calculate the total RTAS error
log size and avoid using the hard-coded header size of 8 bytes.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260627104730.276858-4-thorsten.blum@linux.dev
Now that struct rtas_error_log uses a flexible array member for the
extended log buffer, use struct_size() to calculate the total RTAS error
log size and avoid using the hard-coded header size of 8 bytes.
Use min() to replace the open-coded implementation while at it.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260627104730.276858-3-thorsten.blum@linux.dev
