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Message-Id: <1420647405-3907-2-git-send-email-suzuki.poulose@arm.com>
Date: Wed, 7 Jan 2015 16:16:44 +0000
From: "Suzuki K. Poulose" <suzuki.poulose@....com>
To: linux-arm-kernel@...ts.infradead.org
Cc: leo.yan@...aro.org, yexl@...vell.com, will.deacon@....com,
mark.rultand@....com, catalin.marinas@....com,
linux-kernel@...r.kernel.org,
"Suzuki K. Poulose" <suzuki.poulose@....com>,
Mark Rutland <mark.rutland@....com>
Subject: [PATCH 1/2] arm64: Consolidate hotplug notifier for instruction emulation
From: "Suzuki K. Poulose" <suzuki.poulose@....com>
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
when it comes back online based on the state of the hooks.
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@....com>
Signed-off-by: Mark Rutland <mark.rutland@....com>
---
arch/arm64/kernel/armv8_deprecated.c | 99 +++++++++++++++++-----------------
1 file changed, 50 insertions(+), 49 deletions(-)
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index c363671..9054447 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -46,7 +46,7 @@ struct insn_emulation_ops {
const char *name;
enum legacy_insn_status status;
struct undef_hook *hooks;
- int (*set_hw_mode)(bool enable);
+ void (*set_hw_mode)(void *enable);
};
struct insn_emulation {
@@ -85,6 +85,30 @@ static void remove_emulation_hooks(struct insn_emulation_ops *ops)
pr_notice("Removed %s emulation handler\n", ops->name);
}
+/* Run set_hw_mode(action) on all active CPUs */
+static int run_all_cpu_set_hw_mode(struct insn_emulation *insn, bool action)
+{
+ if (!insn->ops->set_hw_mode)
+ return -EINVAL;
+ on_each_cpu(insn->ops->set_hw_mode, (void *)action, true);
+ return 0;
+}
+
+/* Run set_hw_mode for all insns on a starting CPU */
+static void run_all_insn_set_hw_mode(void)
+{
+ unsigned long flags;
+ struct insn_emulation *insn;
+
+ raw_spin_lock_irqsave(&insn_emulation_lock, flags);
+ list_for_each_entry(insn, &insn_emulation, node) {
+ bool hw_mode = (insn->current_mode == INSN_HW);
+ if (insn->ops->set_hw_mode)
+ insn->ops->set_hw_mode((void *)hw_mode);
+ }
+ raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
+}
+
static int update_insn_emulation_mode(struct insn_emulation *insn,
enum insn_emulation_mode prev)
{
@@ -97,10 +121,8 @@ 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 +133,9 @@ 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 +154,8 @@ 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:
@@ -453,7 +476,7 @@ ret:
return 0;
}
-#define SCTLR_EL1_CP15BEN (1 << 5)
+#define SCTLR_EL1_CP15BEN (1 << 5)
static inline void config_sctlr_el1(u32 clear, u32 set)
{
@@ -465,48 +488,12 @@ 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)
+static void cp15_barrier_set_hw_mode(void *enable)
{
- 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);
}
static struct undef_hook cp15_barrier_hooks[] = {
@@ -534,6 +521,19 @@ 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)
+{
+ if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING)
+ run_all_insn_set_hw_mode();
+
+ return NOTIFY_DONE;
+}
+
+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 +545,7 @@ 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;
--
1.7.9.5
--
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