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| author |   Julien Thierry <julien.thierry@arm.com> | 2019-01-31 14:58:46 +0000 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2019-02-06 10:05:18 +0000 |
| commit | 133d05186325ce04494ea6488a6b86e50a446c12 (patch) | |
| tree | 3d9b43fc48c46a1d94978aa6e20dfaae32920cdc /arch/arm64/kernel | |
| parent | arm64: ptrace: Provide definitions for PMR values (diff) | |
| download | linux-dev-133d05186325ce04494ea6488a6b86e50a446c12.tar.xz linux-dev-133d05186325ce04494ea6488a6b86e50a446c12.zip | |
arm64: Make PMR part of task context
In order to replace PSR.I interrupt disabling/enabling with ICC_PMR_EL1
interrupt masking, ICC_PMR_EL1 needs to be saved/restored when
taking/returning from an exception. This mimics the way hardware saves
and restores PSR.I bit in spsr_el1 for exceptions and ERET.
Add PMR to the registers to save in the pt_regs struct upon kernel entry,
and restore it before ERET. Also, initialize it to a sane value when
creating new tasks.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 14 | ||||
| -rw-r--r-- | arch/arm64/kernel/process.c | 6 |
3 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 0552b91d7666..7f40dcbdd51d 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -73,6 +73,7 @@ int main(void) DEFINE(S_PC, offsetof(struct pt_regs, pc)); DEFINE(S_SYSCALLNO, offsetof(struct pt_regs, syscallno)); DEFINE(S_ORIG_ADDR_LIMIT, offsetof(struct pt_regs, orig_addr_limit)); + DEFINE(S_PMR_SAVE, offsetof(struct pt_regs, pmr_save)); DEFINE(S_STACKFRAME, offsetof(struct pt_regs, stackframe)); DEFINE(S_FRAME_SIZE, sizeof(struct pt_regs)); BLANK(); diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 4d0c81f29a60..02f809a5c823 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -249,6 +249,12 @@ alternative_else_nop_endif msr sp_el0, tsk .endif + /* Save pmr */ +alternative_if ARM64_HAS_IRQ_PRIO_MASKING + mrs_s x20, SYS_ICC_PMR_EL1 + str x20, [sp, #S_PMR_SAVE] +alternative_else_nop_endif + /* * Registers that may be useful after this macro is invoked: * @@ -269,6 +275,14 @@ alternative_else_nop_endif /* No need to restore UAO, it will be restored from SPSR_EL1 */ .endif + /* Restore pmr */ +alternative_if ARM64_HAS_IRQ_PRIO_MASKING + ldr x20, [sp, #S_PMR_SAVE] + msr_s SYS_ICC_PMR_EL1, x20 + /* Ensure priority change is seen by redistributor */ + dsb sy +alternative_else_nop_endif + ldp x21, x22, [sp, #S_PC] // load ELR, SPSR .if \el == 0 ct_user_enter diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index a0f985a6ac50..6d410fc2849b 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -232,6 +232,9 @@ void __show_regs(struct pt_regs *regs) printk("sp : %016llx\n", sp); + if (system_uses_irq_prio_masking()) + printk("pmr_save: %08llx\n", regs->pmr_save); + i = top_reg; while (i >= 0) { @@ -363,6 +366,9 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) childregs->pstate |= PSR_SSBS_BIT; + if (system_uses_irq_prio_masking()) + childregs->pmr_save = GIC_PRIO_IRQON; + p->thread.cpu_context.x19 = stack_start; p->thread.cpu_context.x20 = stk_sz; } |