| Message ID | 20260831-icache-parity-error-v1-1-55078fd4e743@bootlin.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | powerpc/traps: Recover from L1 instruction cache parity errors on e500v2 | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 5 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 22 jobs. |
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 629f2a2d4780..f8a4019153a0 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -724,8 +724,21 @@ int machine_check_e500(struct pt_regs *regs) if (reason & MCSR_MCP) pr_cont("Machine Check Signal\n"); - if (reason & MCSR_ICPERR) + if (reason & MCSR_ICPERR) { pr_cont("Instruction Cache Parity Error\n"); + + /* + * This is recoverable by invalidating the I-Cache. + * The I-cache flash invalidate clears all lines; + * correct instructions will be re-fetched from memory. + */ + mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI); + while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI) + ; + + return 1; + } + if (reason & MCSR_DCP_PERR) pr_cont("Data Cache Push Parity Error\n"); if (reason & MCSR_DCPERR)
There is no attempt to recover from an L1 instruction cache parity error on e500v2 platforms. When this kind of error happens, we fall in the die_mce() while we could recover from it (cf §3.1 in [1]) Implement a similar recovery than the one implemented on the e500mc platforms. It consists of invalidating the entire L1 instruction cache when parity errors are detected. [1]: https://www.nxp.jp/docs/en/application-note/AN3532.pdf Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com> --- Hi all, There is a real use case behind this: the device I'm working on is a space product. It encounters this kind of parity errors when it gets hit by radiations. To test it, I made a module that triggers the parity errors by a register of the P2020 that allows to corrupt the cache, you can find this module here: https://github.com/bastien-curutchet/linux/tree/b4/icache-parity-error --- arch/powerpc/kernel/traps.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) --- base-commit: 0fed5eb44e49e79d824edc4ccce012bb57994300 change-id: 20260831-icache-parity-error-b8c6b1ca0a64 Best regards,