[PATCH 8/9] arm64: Deprecate old local_daif_{mask,save,restore}
From: Liao Chang
Date: Mon Apr 08 2024 - 21:31:28 EST
The new exception masking helpers offer a simpler, more consistent, and
potentially more maintainable interface for managing DAIF + PMR + ALLINT,
which are selected by the CONFIG_ARM64_NMI or CONFIG_ARM64_PSEUDO_NMI.
This patch initiates the deprecation of the local_daif_xxx functions in
favor of the newly introduced exception masking methods on arm64.
Signed-off-by: Liao Chang <liaochang1@xxxxxxxxxx>
---
arch/arm64/include/asm/daifflags.h | 118 ++++-------------------------
arch/arm64/kernel/acpi.c | 10 +--
arch/arm64/kernel/debug-monitors.c | 7 +-
arch/arm64/kernel/hibernate.c | 6 +-
arch/arm64/kernel/irq.c | 2 +-
arch/arm64/kernel/machine_kexec.c | 2 +-
arch/arm64/kernel/setup.c | 2 +-
arch/arm64/kernel/smp.c | 6 +-
arch/arm64/kernel/suspend.c | 6 +-
arch/arm64/kvm/hyp/vgic-v3-sr.c | 6 +-
arch/arm64/kvm/hyp/vhe/switch.c | 4 +-
arch/arm64/mm/mmu.c | 6 +-
12 files changed, 44 insertions(+), 131 deletions(-)
diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h
index 6d391d221432..b831def08bb3 100644
--- a/arch/arm64/include/asm/daifflags.h
+++ b/arch/arm64/include/asm/daifflags.h
@@ -18,109 +18,6 @@
#define DAIF_ERRCTX (PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
#define DAIF_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
-
-/* mask/save/unmask/restore all exceptions, including interrupts. */
-static inline void local_daif_mask(void)
-{
- WARN_ON(system_has_prio_mask_debugging() &&
- (read_sysreg_s(SYS_ICC_PMR_EL1) == (GIC_PRIO_IRQOFF |
- GIC_PRIO_PSR_I_SET)));
-
- asm volatile(
- "msr daifset, #0xf // local_daif_mask\n"
- :
- :
- : "memory");
-
- /* Don't really care for a dsb here, we don't intend to enable IRQs */
- if (system_uses_irq_prio_masking())
- gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
-
- trace_hardirqs_off();
-}
-
-static inline unsigned long local_daif_save_flags(void)
-{
- unsigned long flags;
-
- flags = read_sysreg(daif);
-
- if (system_uses_irq_prio_masking()) {
- /* If IRQs are masked with PMR, reflect it in the flags */
- if (read_sysreg_s(SYS_ICC_PMR_EL1) != GIC_PRIO_IRQON)
- flags |= PSR_I_BIT | PSR_F_BIT;
- }
-
- return flags;
-}
-
-static inline unsigned long local_daif_save(void)
-{
- unsigned long flags;
-
- flags = local_daif_save_flags();
-
- local_daif_mask();
-
- return flags;
-}
-
-static inline void local_daif_restore(unsigned long flags)
-{
- bool irq_disabled = flags & PSR_I_BIT;
-
- WARN_ON(system_has_prio_mask_debugging() &&
- (read_sysreg(daif) & (PSR_I_BIT | PSR_F_BIT)) != (PSR_I_BIT | PSR_F_BIT));
-
- if (!irq_disabled) {
- trace_hardirqs_on();
-
- if (system_uses_irq_prio_masking()) {
- gic_write_pmr(GIC_PRIO_IRQON);
- pmr_sync();
- }
- } else if (system_uses_irq_prio_masking()) {
- u64 pmr;
-
- if (!(flags & PSR_A_BIT)) {
- /*
- * If interrupts are disabled but we can take
- * asynchronous errors, we can take NMIs
- */
- flags &= ~(PSR_I_BIT | PSR_F_BIT);
- pmr = GIC_PRIO_IRQOFF;
- } else {
- pmr = GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET;
- }
-
- /*
- * There has been concern that the write to daif
- * might be reordered before this write to PMR.
- * From the ARM ARM DDI 0487D.a, section D1.7.1
- * "Accessing PSTATE fields":
- * Writes to the PSTATE fields have side-effects on
- * various aspects of the PE operation. All of these
- * side-effects are guaranteed:
- * - Not to be visible to earlier instructions in
- * the execution stream.
- * - To be visible to later instructions in the
- * execution stream
- *
- * Also, writes to PMR are self-synchronizing, so no
- * interrupts with a lower priority than PMR is signaled
- * to the PE after the write.
- *
- * So we don't need additional synchronization here.
- */
- gic_write_pmr(pmr);
- }
-
- write_sysreg(flags, daif);
-
- if (irq_disabled)
- trace_hardirqs_off();
-}
-
/*
* For Arm64 processor support Armv8.8 or later, kernel supports three types
* of irqflags, they used for corresponding configuration depicted as below:
@@ -146,6 +43,7 @@ union arch_irqflags {
};
typedef union arch_irqflags arch_irqflags_t;
+#define ARCH_IRQFLAGS_INITIALIZER { .flags = 0UL }
static inline void __pmr_local_allint_mask(void)
{
@@ -164,6 +62,7 @@ static inline void __nmi_local_allint_mask(void)
_allint_set();
}
+/* mask/save/unmask/restore all exceptions, including interrupts. */
static inline void local_allint_mask(void)
{
asm volatile(
@@ -418,4 +317,17 @@ static inline void local_errint_enable(void)
irqflags.fields.allint = 0;
local_allint_restore(irqflags);
}
+
+/*
+ * local_errnmi_enable - Enable Serror and NMI with or without superpriority.
+ */
+static inline void local_errnmi_enable(void)
+{
+ arch_irqflags_t irqflags;
+
+ irqflags.fields.daif = DAIF_PROCCTX_NOIRQ;
+ irqflags.fields.pmr = GIC_PRIO_IRQOFF;
+ irqflags.fields.allint = 0;
+ local_allint_restore(irqflags);
+}
#endif
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index dba8fcec7f33..0cda765b2ae8 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -365,12 +365,12 @@ int apei_claim_sea(struct pt_regs *regs)
{
int err = -ENOENT;
bool return_to_irqs_enabled;
- unsigned long current_flags;
+ arch_irqflags_t current_flags;
if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
return err;
- current_flags = local_daif_save_flags();
+ current_flags = local_allint_save_flags();
/* current_flags isn't useful here as daif doesn't tell us about pNMI */
return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
@@ -382,7 +382,7 @@ int apei_claim_sea(struct pt_regs *regs)
* SEA can interrupt SError, mask it and describe this as an NMI so
* that APEI defers the handling.
*/
- local_daif_restore(DAIF_ERRCTX);
+ local_errint_disable();
nmi_enter();
err = ghes_notify_sea();
nmi_exit();
@@ -393,7 +393,7 @@ int apei_claim_sea(struct pt_regs *regs)
*/
if (!err) {
if (return_to_irqs_enabled) {
- local_daif_restore(DAIF_PROCCTX_NOIRQ);
+ local_errnmi_enable();
__irq_enter();
irq_work_run();
__irq_exit();
@@ -403,7 +403,7 @@ int apei_claim_sea(struct pt_regs *regs)
}
}
- local_daif_restore(current_flags);
+ local_allint_restore(current_flags);
return err;
}
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 64f2ecbdfe5c..559162a89a69 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -36,10 +36,11 @@ u8 debug_monitors_arch(void)
*/
static void mdscr_write(u32 mdscr)
{
- unsigned long flags;
- flags = local_daif_save();
+ arch_irqflags_t flags;
+
+ flags = local_allint_save();
write_sysreg(mdscr, mdscr_el1);
- local_daif_restore(flags);
+ local_allint_restore(flags);
}
NOKPROBE_SYMBOL(mdscr_write);
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 02870beb271e..3f0d276121d3 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -327,7 +327,7 @@ static void swsusp_mte_restore_tags(void)
int swsusp_arch_suspend(void)
{
int ret = 0;
- unsigned long flags;
+ arch_irqflags_t flags;
struct sleep_stack_data state;
if (cpus_are_stuck_in_kernel()) {
@@ -335,7 +335,7 @@ int swsusp_arch_suspend(void)
return -EBUSY;
}
- flags = local_daif_save();
+ flags = local_allint_save();
if (__cpu_suspend_enter(&state)) {
/* make the crash dump kernel image visible/saveable */
@@ -385,7 +385,7 @@ int swsusp_arch_suspend(void)
spectre_v4_enable_mitigation(NULL);
}
- local_daif_restore(flags);
+ local_allint_restore(flags);
return ret;
}
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 85087e2df564..610e6249871a 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -132,6 +132,6 @@ void __init init_IRQ(void)
* the PMR/PSR pair to a consistent state.
*/
WARN_ON(read_sysreg(daif) & PSR_A_BIT);
- local_daif_restore(DAIF_PROCCTX_NOIRQ);
+ local_errnmi_enable();
}
}
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 82e2203d86a3..412f90c188dc 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -176,7 +176,7 @@ void machine_kexec(struct kimage *kimage)
pr_info("Bye!\n");
- local_daif_mask();
+ local_allint_mask();
/*
* Both restart and kernel_reloc will shutdown the MMU, disable data
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 65a052bf741f..7f1805231efb 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -301,7 +301,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
* Unmask SError as soon as possible after initializing earlycon so
* that we can report any SErrors immediately.
*/
- local_daif_restore(DAIF_PROCCTX_NOIRQ);
+ local_errnmi_enable();
/*
* TTBR0 is only used for the identity mapping at this stage. Make it
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 4ced34f62dab..bc5191e52fee 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -264,7 +264,7 @@ asmlinkage notrace void secondary_start_kernel(void)
set_cpu_online(cpu, true);
complete(&cpu_running);
- local_daif_restore(DAIF_PROCCTX);
+ local_errint_enable();
/*
* OK, it's off to the idle thread for us
@@ -371,7 +371,7 @@ void __noreturn cpu_die(void)
idle_task_exit();
- local_daif_mask();
+ local_allint_mask();
/* Tell cpuhp_bp_sync_dead() that this CPU is now safe to dispose of */
cpuhp_ap_report_dead();
@@ -810,7 +810,7 @@ static void __noreturn local_cpu_stop(void)
{
set_cpu_online(smp_processor_id(), false);
- local_daif_mask();
+ local_allint_mask();
sdei_mask_local_cpu();
cpu_park_loop();
}
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index eaaff94329cd..4736015be55d 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -97,7 +97,7 @@ void notrace __cpu_suspend_exit(void)
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
int ret = 0;
- unsigned long flags;
+ arch_irqflags_t flags;
struct sleep_stack_data state;
struct arm_cpuidle_irq_context context;
@@ -122,7 +122,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
* hardirqs should be firmly off by now. This really ought to use
* something like raw_local_daif_save().
*/
- flags = local_daif_save();
+ flags = local_allint_save();
/*
* Function graph tracer state gets inconsistent when the kernel
@@ -168,7 +168,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
* restored, so from this point onwards, debugging is fully
* reenabled if it was enabled when core started shutdown.
*/
- local_daif_restore(flags);
+ local_allint_restore(flags);
return ret;
}
diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 6cb638b184b1..6a0d1b8cb8ef 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -414,7 +414,7 @@ void __vgic_v3_init_lrs(void)
u64 __vgic_v3_get_gic_config(void)
{
u64 val, sre = read_gicreg(ICC_SRE_EL1);
- unsigned long flags = 0;
+ arch_irqflags_t flags = ARCH_IRQFLAGS_INITIALIZER;
/*
* To check whether we have a MMIO-based (GICv2 compatible)
@@ -427,7 +427,7 @@ u64 __vgic_v3_get_gic_config(void)
* EL2.
*/
if (has_vhe())
- flags = local_daif_save();
+ flags = local_allint_save();
/*
* Table 11-2 "Permitted ICC_SRE_ELx.SRE settings" indicates
@@ -447,7 +447,7 @@ u64 __vgic_v3_get_gic_config(void)
isb();
if (has_vhe())
- local_daif_restore(flags);
+ local_allint_restore(flags);
val = (val & ICC_SRE_EL1_SRE) ? 0 : (1ULL << 63);
val |= read_gicreg(ICH_VTR_EL2);
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 1581df6aec87..ace4fd6bce46 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -271,7 +271,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
{
int ret;
- local_daif_mask();
+ local_allint_mask();
/*
* Having IRQs masked via PMR when entering the guest means the GIC
@@ -290,7 +290,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
* local_daif_restore() takes care to properly restore PSTATE.DAIF
* and the GIC PMR if the host is using IRQ priorities.
*/
- local_daif_restore(DAIF_PROCCTX_NOIRQ);
+ local_errnmi_enable();
/*
* When we exit from the guest we change a number of CPU configuration
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 495b732d5af3..eab7608cf88d 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1513,7 +1513,7 @@ void __cpu_replace_ttbr1(pgd_t *pgdp, bool cnp)
typedef void (ttbr_replace_func)(phys_addr_t);
extern ttbr_replace_func idmap_cpu_replace_ttbr1;
ttbr_replace_func *replace_phys;
- unsigned long daif;
+ arch_irqflags_t flags;
/* phys_to_ttbr() zeros lower 2 bits of ttbr with 52-bit PA */
phys_addr_t ttbr1 = phys_to_ttbr(virt_to_phys(pgdp));
@@ -1529,9 +1529,9 @@ void __cpu_replace_ttbr1(pgd_t *pgdp, bool cnp)
* We really don't want to take *any* exceptions while TTBR1 is
* in the process of being replaced so mask everything.
*/
- daif = local_daif_save();
+ flags = local_allint_save();
replace_phys(ttbr1);
- local_daif_restore(daif);
+ local_allint_restore(flags);
cpu_uninstall_idmap();
}
--
2.34.1