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| author |   Haren Myneni <haren@linux.ibm.com> | 2022-09-27 18:29:27 -0700 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-09-28 22:52:32 +1000 |
| commit | 335e1a91042764629fbbcd8c7e40379fa3762d35 (patch) | |
| tree | 55acaa75b51655c7f57c9f9bf39db29596449ddc /arch/powerpc/mm | |
| parent | powerpc: Reverse stack frame marker on little endian (diff) | |
| download | linux-dev-335e1a91042764629fbbcd8c7e40379fa3762d35.tar.xz linux-dev-335e1a91042764629fbbcd8c7e40379fa3762d35.zip | |
powerpc: Ignore DSI error caused by the copy/paste instruction
The data storage interrupt (DSI) error will be generated when the
paste operation is issued on the suspended Nest Accelerator (NX)
window due to NX state changes. The hypervisor expects the
partition to ignore this error during page fault handling.
To differentiate DSI caused by an actual HW configuration or by
the NX window, a new “ibm,pi-features” type value is defined.
Byte 0, bit 3 of pi-attribute-specifier-type is now defined to
indicate this DSI error. If this error is not ignored, the user
space can get SIGBUS when the NX request is issued.
This patch adds changes to read ibm,pi-features property and ignore
DSI error during page fault handling if MMU_FTR_NX_DSI is defined.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Mention PAPR version in comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b9cd844b85eb8f70459109ce1b14e44c4cc85fa7.camel@linux.ibm.com
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 1566804e4b3d..2bef19cc1b98 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -371,7 +371,22 @@ static void sanity_check_fault(bool is_write, bool is_user, #elif defined(CONFIG_PPC_8xx) #define page_fault_is_bad(__err) ((__err) & DSISR_NOEXEC_OR_G) #elif defined(CONFIG_PPC64) -#define page_fault_is_bad(__err) ((__err) & DSISR_BAD_FAULT_64S) +static int page_fault_is_bad(unsigned long err) +{ + unsigned long flag = DSISR_BAD_FAULT_64S; + + /* + * PAPR+ v2.11 § 14.15.3.4.1 (unreleased) + * If byte 0, bit 3 of pi-attribute-specifier-type in + * ibm,pi-features property is defined, ignore the DSI error + * which is caused by the paste instruction on the + * suspended NX window. + */ + if (mmu_has_feature(MMU_FTR_NX_DSI)) + flag &= ~DSISR_BAD_COPYPASTE; + + return err & flag; +} #else #define page_fault_is_bad(__err) ((__err) & DSISR_BAD_FAULT_32S) #endif |