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| author |   Mark Brown <broonie@kernel.org> | 2021-12-07 16:32:50 +0000 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2021-12-14 18:36:19 +0000 |
| commit | 12b792e5e2344772434ea817572bedde8ad9c172 (patch) | |
| tree | 24fbf2832e470498249a1b9d7ad5ff88f902fea9 /arch/arm64/kernel/fpsimd.c | |
| parent | arm64: mm: Use asid feature macro for cheanup (diff) | |
| download | linux-dev-12b792e5e2344772434ea817572bedde8ad9c172.tar.xz linux-dev-12b792e5e2344772434ea817572bedde8ad9c172.zip | |
arm64/fp: Add comments documenting the usage of state restore functions
Add comments to help people figure out when fpsimd_bind_state_to_cpu() and
fpsimd_update_current_state() are used.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211207163250.1373542-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/fpsimd.c')
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index fa244c426f61..aad59051b3b7 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1213,7 +1213,8 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state, /* * Load the userland FPSIMD state of 'current' from memory, but only if the * FPSIMD state already held in the registers is /not/ the most recent FPSIMD - * state of 'current' + * state of 'current'. This is called when we are preparing to return to + * userspace to ensure that userspace sees a good register state. */ void fpsimd_restore_current_state(void) { @@ -1244,7 +1245,9 @@ void fpsimd_restore_current_state(void) /* * Load an updated userland FPSIMD state for 'current' from memory and set the * flag that indicates that the FPSIMD register contents are the most recent - * FPSIMD state of 'current' + * FPSIMD state of 'current'. This is used by the signal code to restore the + * register state when returning from a signal handler in FPSIMD only cases, + * any SVE context will be discarded. */ void fpsimd_update_current_state(struct user_fpsimd_state const *state) { |