Commit 5cf9ce6e authored by Marc Zyngier's avatar Marc Zyngier Committed by Catalin Marinas

arm64: Add per-cpu infrastructure to call ARCH_WORKAROUND_2

In a heterogeneous system, we can end up with both affected and
unaffected CPUs. Let's check their status before calling into the
firmware.
Reviewed-by: default avatarJulien Grall <julien.grall@arm.com>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 8e290624
......@@ -233,6 +233,8 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
#endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */
#ifdef CONFIG_ARM64_SSBD
DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
void __init arm64_update_smccc_conduit(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr,
int nr_inst)
......
......@@ -140,8 +140,10 @@ alternative_else_nop_endif
// This macro corrupts x0-x3. It is the caller's duty
// to save/restore them if required.
.macro apply_ssbd, state
.macro apply_ssbd, state, targ, tmp1, tmp2
#ifdef CONFIG_ARM64_SSBD
ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1
cbz \tmp2, \targ
mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2
mov w1, #\state
alternative_cb arm64_update_smccc_conduit
......@@ -176,12 +178,13 @@ alternative_cb_end
ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug
disable_step_tsk x19, x20 // exceptions when scheduling.
apply_ssbd 1
apply_ssbd 1, 1f, x22, x23
#ifdef CONFIG_ARM64_SSBD
ldp x0, x1, [sp, #16 * 0]
ldp x2, x3, [sp, #16 * 1]
#endif
1:
mov x29, xzr // fp pointed to user-space
.else
......@@ -323,8 +326,8 @@ alternative_if ARM64_WORKAROUND_845719
alternative_else_nop_endif
#endif
3:
apply_ssbd 0
apply_ssbd 0, 5f, x0, x1
5:
.endif
msr elr_el1, x21 // set up the return data
......
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