From: "Suzuki K. Poulose" suzuki.poulose@arm.com
commit 736d474f0fafd1486f178570bc47660ee9dfdef8 upstream.
As of now each insn_emulation has a cpu hotplug notifier that enables/disables the CPU feature bit for the functionality. This patch re-arranges the code, such that there is only one notifier that runs through the list of registered emulation hooks and runs their corresponding set_hw_mode.
We do nothing when a CPU is dying as we will set the appropriate bits as it comes back online based on the state of the hooks.
Signed-off-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Suzuki K. Poulose suzuki.poulose@arm.com Cc: Will Deacon will.deacon@arm.com Cc: Punit Agrawal punit.agrawal@arm.com [catalin.marinas@arm.com: fix pr_warn compilation error] [catalin.marinas@arm.com: remove unnecessary "insn" check] Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: David Brown david.brown@linaro.org --- arch/arm64/include/asm/cputype.h | 2 + arch/arm64/kernel/armv8_deprecated.c | 125 +++++++++++++++++++++-------------- 2 files changed, 79 insertions(+), 48 deletions(-)
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index ee6403d..68732e9 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -81,6 +81,8 @@ #define ID_AA64MMFR0_BIGEND(mmfr0) \ (((mmfr0) & ID_AA64MMFR0_BIGEND_MASK) >> ID_AA64MMFR0_BIGEND_SHIFT)
+#define SCTLR_EL1_CP15BEN (0x1 << 5) + #ifndef __ASSEMBLY__
/* diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index c363671..68b955e 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -19,6 +19,7 @@ #include <asm/system_misc.h> #include <asm/traps.h> #include <asm/uaccess.h> +#include <asm/cpufeature.h>
#define CREATE_TRACE_POINTS #include "trace-events-emulation.h" @@ -85,6 +86,57 @@ static void remove_emulation_hooks(struct insn_emulation_ops *ops) pr_notice("Removed %s emulation handler\n", ops->name); }
+static void enable_insn_hw_mode(void *data) +{ + struct insn_emulation *insn = (struct insn_emulation *)data; + if (insn->ops->set_hw_mode) + insn->ops->set_hw_mode(true); +} + +static void disable_insn_hw_mode(void *data) +{ + struct insn_emulation *insn = (struct insn_emulation *)data; + if (insn->ops->set_hw_mode) + insn->ops->set_hw_mode(false); +} + +/* Run set_hw_mode(mode) on all active CPUs */ +static int run_all_cpu_set_hw_mode(struct insn_emulation *insn, bool enable) +{ + if (!insn->ops->set_hw_mode) + return -EINVAL; + if (enable) + on_each_cpu(enable_insn_hw_mode, (void *)insn, true); + else + on_each_cpu(disable_insn_hw_mode, (void *)insn, true); + return 0; +} + +/* + * Run set_hw_mode for all insns on a starting CPU. + * Returns: + * 0 - If all the hooks ran successfully. + * -EINVAL - At least one hook is not supported by the CPU. + */ +static int run_all_insn_set_hw_mode(unsigned long cpu) +{ + int rc = 0; + unsigned long flags; + struct insn_emulation *insn; + + raw_spin_lock_irqsave(&insn_emulation_lock, flags); + list_for_each_entry(insn, &insn_emulation, node) { + bool enable = (insn->current_mode == INSN_HW); + if (insn->ops->set_hw_mode && insn->ops->set_hw_mode(enable)) { + pr_warn("CPU[%ld] cannot support the emulation of %s", + cpu, insn->ops->name); + rc = -EINVAL; + } + } + raw_spin_unlock_irqrestore(&insn_emulation_lock, flags); + return rc; +} + static int update_insn_emulation_mode(struct insn_emulation *insn, enum insn_emulation_mode prev) { @@ -97,10 +149,8 @@ static int update_insn_emulation_mode(struct insn_emulation *insn, remove_emulation_hooks(insn->ops); break; case INSN_HW: - if (insn->ops->set_hw_mode) { - insn->ops->set_hw_mode(false); + if (!run_all_cpu_set_hw_mode(insn, false)) pr_notice("Disabled %s support\n", insn->ops->name); - } break; }
@@ -111,10 +161,9 @@ static int update_insn_emulation_mode(struct insn_emulation *insn, register_emulation_hooks(insn->ops); break; case INSN_HW: - if (insn->ops->set_hw_mode && insn->ops->set_hw_mode(true)) + ret = run_all_cpu_set_hw_mode(insn, true); + if (!ret) pr_notice("Enabled %s support\n", insn->ops->name); - else - ret = -EINVAL; break; }
@@ -133,6 +182,8 @@ static void register_insn_emulation(struct insn_emulation_ops *ops) switch (ops->status) { case INSN_DEPRECATED: insn->current_mode = INSN_EMULATE; + /* Disable the HW mode if it was turned on at early boot time */ + run_all_cpu_set_hw_mode(insn, false); insn->max = INSN_HW; break; case INSN_OBSOLETE: @@ -453,8 +504,6 @@ ret: return 0; }
-#define SCTLR_EL1_CP15BEN (1 << 5) - static inline void config_sctlr_el1(u32 clear, u32 set) { u32 val; @@ -465,48 +514,13 @@ static inline void config_sctlr_el1(u32 clear, u32 set) asm volatile("msr sctlr_el1, %0" : : "r" (val)); }
-static void enable_cp15_ben(void *info) -{ - config_sctlr_el1(0, SCTLR_EL1_CP15BEN); -} - -static void disable_cp15_ben(void *info) -{ - config_sctlr_el1(SCTLR_EL1_CP15BEN, 0); -} - -static int cpu_hotplug_notify(struct notifier_block *b, - unsigned long action, void *hcpu) -{ - switch (action) { - case CPU_STARTING: - case CPU_STARTING_FROZEN: - enable_cp15_ben(NULL); - return NOTIFY_DONE; - case CPU_DYING: - case CPU_DYING_FROZEN: - disable_cp15_ben(NULL); - return NOTIFY_DONE; - } - - return NOTIFY_OK; -} - -static struct notifier_block cpu_hotplug_notifier = { - .notifier_call = cpu_hotplug_notify, -}; - static int cp15_barrier_set_hw_mode(bool enable) { - if (enable) { - register_cpu_notifier(&cpu_hotplug_notifier); - on_each_cpu(enable_cp15_ben, NULL, true); - } else { - unregister_cpu_notifier(&cpu_hotplug_notifier); - on_each_cpu(disable_cp15_ben, NULL, true); - } - - return true; + if (enable) + config_sctlr_el1(0, SCTLR_EL1_CP15BEN); + else + config_sctlr_el1(SCTLR_EL1_CP15BEN, 0); + return 0; }
static struct undef_hook cp15_barrier_hooks[] = { @@ -534,6 +548,20 @@ static struct insn_emulation_ops cp15_barrier_ops = { .set_hw_mode = cp15_barrier_set_hw_mode, };
+static int insn_cpu_hotplug_notify(struct notifier_block *b, + unsigned long action, void *hcpu) +{ + int rc = 0; + if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING) + rc = run_all_insn_set_hw_mode((unsigned long)hcpu); + + return notifier_from_errno(rc); +} + +static struct notifier_block insn_cpu_hotplug_notifier = { + .notifier_call = insn_cpu_hotplug_notify, +}; + /* * Invoked as late_initcall, since not needed before init spawned. */ @@ -545,6 +573,7 @@ static int __init armv8_deprecated_init(void) if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION)) register_insn_emulation(&cp15_barrier_ops);
+ register_cpu_notifier(&insn_cpu_hotplug_notifier); register_insn_emulation_sysctl(ctl_abi);
return 0;