mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-11-01 00:48:50 +00:00
Code Issues Releases Wiki Activity

arm64/sme: Restore SME registers on exit from suspend

Browse source 
The fields in SMCR_EL1 and SMPRI_EL1 reset to an architecturally UNKNOWN
value. Since we do not otherwise manage the traps configured in this
register at runtime we need to reconfigure them after a suspend in case
nothing else was kind enough to preserve them for us.

The vector length will be restored as part of restoring the SME state for
the next SME using task.

Fixes: a1f4ccd25c ("arm64/sme: Provide Kconfig for SME")
Reported-by: Jackson Cooper-Driver <Jackson.Cooper-Driver@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-1-17e05e493471@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Mark Brown 2024-02-13 23:06:32 +00:00 committed by Will Deacon
parent a6b3eb304a
commit 9533864816
3 changed files with 19 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/arm64/include/asm/fpsimd.h
View file

@ -386,6 +386,7 @@ extern void sme_alloc(struct task_struct *task, bool flush);
extern unsigned int sme_get_vl(void);
extern int sme_set_current_vl(unsigned long arg);
extern int sme_get_current_vl(void);
extern void sme_suspend_exit(void);
/*
* Return how many bytes of memory are required to store the full SME
@ -421,6 +422,7 @@ static inline int sme_max_vl(void) { return 0; }
static inline int sme_max_virtualisable_vl(void) { return 0; }
static inline int sme_set_current_vl(unsigned long arg) { return -EINVAL; }
static inline int sme_get_current_vl(void) { return -EINVAL; }
static inline void sme_suspend_exit(void) { }
static inline size_t sme_state_size(struct task_struct const *task)
{

14
arch/arm64/kernel/fpsimd.c
View file

@ -1311,6 +1311,20 @@ void __init sme_setup(void)
get_sme_default_vl());
}
void sme_suspend_exit(void)
{
u64 smcr = 0;
if (!system_supports_sme())
return;
if (system_supports_fa64())
smcr |= SMCR_ELx_FA64;
write_sysreg_s(smcr, SYS_SMCR_EL1);
write_sysreg_s(0, SYS_SMPRI_EL1);
}
#endif /* CONFIG_ARM64_SME */
static void sve_init_regs(void)

3
arch/arm64/kernel/suspend.c
View file

@ -12,6 +12,7 @@
#include <asm/daifflags.h>
#include <asm/debug-monitors.h>
#include <asm/exec.h>
#include <asm/fpsimd.h>
#include <asm/mte.h>
#include <asm/memory.h>
#include <asm/mmu_context.h>
@ -80,6 +81,8 @@ void notrace __cpu_suspend_exit(void)
*/
spectre_v4_enable_mitigation(NULL);
sme_suspend_exit();
/* Restore additional feature-specific configuration */
ptrauth_suspend_exit();
}