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| author | Kristina Martsenko <kristina.martsenko@arm.com> | 2023-05-09 17:22:31 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-06-05 19:05:41 +0300 |
| commit | 8536ceaa747174ded7983f13906b225e0c33ac51 (patch) | |
| tree | 9b4743616447691e73ea44b77221bce88133f197 /arch/arm64/kernel/entry-common.c | |
| parent | 3172613fbcbb0634d91d05601f029da0c1466999 (diff) | |
| download | linux-8536ceaa747174ded7983f13906b225e0c33ac51.tar.xz | |
arm64: mops: handle MOPS exceptions
The memory copy/set instructions added as part of FEAT_MOPS can take an
exception (e.g. page fault) part-way through their execution and resume
execution afterwards.
If however the task is re-scheduled and execution resumes on a different
CPU, then the CPU may take a new type of exception to indicate this.
This is because the architecture allows two options (Option A and Option
B) to implement the instructions and a heterogeneous system can have
different implementations between CPUs.
In this case the OS has to reset the registers and restart execution
from the prologue instruction. The algorithm for doing this is provided
as part of the Arm ARM.
Add an exception handler for the new exception and wire it up for
userspace tasks.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20230509142235.3284028-8-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/entry-common.c')
| -rw-r--r-- | arch/arm64/kernel/entry-common.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 3af3c01c93a6..a8ec174e5b0e 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -611,6 +611,14 @@ static void noinstr el0_bti(struct pt_regs *regs) exit_to_user_mode(regs); } +static void noinstr el0_mops(struct pt_regs *regs, unsigned long esr) +{ + enter_from_user_mode(regs); + local_daif_restore(DAIF_PROCCTX); + do_el0_mops(regs, esr); + exit_to_user_mode(regs); +} + static void noinstr el0_inv(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); @@ -688,6 +696,9 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs) case ESR_ELx_EC_BTI: el0_bti(regs); break; + case ESR_ELx_EC_MOPS: + el0_mops(regs, esr); + break; case ESR_ELx_EC_BREAKPT_LOW: case ESR_ELx_EC_SOFTSTP_LOW: case ESR_ELx_EC_WATCHPT_LOW: |