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authorMark Brown <broonie@kernel.org>2022-04-19 14:22:31 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2022-04-22 20:51:21 +0300
commite0838f6373e5cb72516fc4c26bba309097e2a80a (patch)
treedbd5716e33fbfbf7a53a01e6c83f449ae4ba58b8 /arch/arm64/kernel/fpsimd.c
parentd45d7ff7047f7f6c3221b0f028fade640812f931 (diff)
downloadlinux-e0838f6373e5cb72516fc4c26bba309097e2a80a.tar.xz
arm64/sme: Save and restore streaming mode over EFI runtime calls
When saving and restoring the floating point state over an EFI runtime call ensure that we handle streaming mode, only handling FFR if we are not in streaming mode and ensuring that we are in normal mode over the call into runtime services. We currently assume that ZA will not be modified by runtime services, the specification is not yet finalised so this may need updating if that changes. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20220419112247.711548-24-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.c48
1 files changed, 42 insertions, 6 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 9592cdd7d635..64431bc62472 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1056,21 +1056,25 @@ int vec_verify_vq_map(enum vec_type type)
static void __init sve_efi_setup(void)
{
- struct vl_info *info = &vl_info[ARM64_VEC_SVE];
+ int max_vl = 0;
+ int i;
if (!IS_ENABLED(CONFIG_EFI))
return;
+ for (i = 0; i < ARRAY_SIZE(vl_info); i++)
+ max_vl = max(vl_info[i].max_vl, max_vl);
+
/*
* alloc_percpu() warns and prints a backtrace if this goes wrong.
* This is evidence of a crippled system and we are returning void,
* so no attempt is made to handle this situation here.
*/
- if (!sve_vl_valid(info->max_vl))
+ if (!sve_vl_valid(max_vl))
goto fail;
efi_sve_state = __alloc_percpu(
- SVE_SIG_REGS_SIZE(sve_vq_from_vl(info->max_vl)), SVE_VQ_BYTES);
+ SVE_SIG_REGS_SIZE(sve_vq_from_vl(max_vl)), SVE_VQ_BYTES);
if (!efi_sve_state)
goto fail;
@@ -1845,6 +1849,7 @@ EXPORT_SYMBOL(kernel_neon_end);
static DEFINE_PER_CPU(struct user_fpsimd_state, efi_fpsimd_state);
static DEFINE_PER_CPU(bool, efi_fpsimd_state_used);
static DEFINE_PER_CPU(bool, efi_sve_state_used);
+static DEFINE_PER_CPU(bool, efi_sm_state);
/*
* EFI runtime services support functions
@@ -1879,12 +1884,28 @@ void __efi_fpsimd_begin(void)
*/
if (system_supports_sve() && likely(efi_sve_state)) {
char *sve_state = this_cpu_ptr(efi_sve_state);
+ bool ffr = true;
+ u64 svcr;
__this_cpu_write(efi_sve_state_used, true);
+ if (system_supports_sme()) {
+ svcr = read_sysreg_s(SYS_SVCR_EL0);
+
+ if (!system_supports_fa64())
+ ffr = svcr & SYS_SVCR_EL0_SM_MASK;
+
+ __this_cpu_write(efi_sm_state, ffr);
+ }
+
sve_save_state(sve_state + sve_ffr_offset(sve_max_vl()),
&this_cpu_ptr(&efi_fpsimd_state)->fpsr,
- true);
+ ffr);
+
+ if (system_supports_sme())
+ sysreg_clear_set_s(SYS_SVCR_EL0,
+ SYS_SVCR_EL0_SM_MASK, 0);
+
} else {
fpsimd_save_state(this_cpu_ptr(&efi_fpsimd_state));
}
@@ -1907,11 +1928,26 @@ void __efi_fpsimd_end(void)
if (system_supports_sve() &&
likely(__this_cpu_read(efi_sve_state_used))) {
char const *sve_state = this_cpu_ptr(efi_sve_state);
+ bool ffr = true;
+
+ /*
+ * Restore streaming mode; EFI calls are
+ * normal function calls so should not return in
+ * streaming mode.
+ */
+ if (system_supports_sme()) {
+ if (__this_cpu_read(efi_sm_state)) {
+ sysreg_clear_set_s(SYS_SVCR_EL0,
+ 0,
+ SYS_SVCR_EL0_SM_MASK);
+ if (!system_supports_fa64())
+ ffr = efi_sm_state;
+ }
+ }
- sve_set_vq(sve_vq_from_vl(sve_get_vl()) - 1);
sve_load_state(sve_state + sve_ffr_offset(sve_max_vl()),
&this_cpu_ptr(&efi_fpsimd_state)->fpsr,
- true);
+ ffr);
__this_cpu_write(efi_sve_state_used, false);
} else {