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authorSuzuki K. Poulose <suzuki.poulose@arm.com>2015-01-21 12:43:10 +0000
committerDavid Brown <david.brown@linaro.org>2015-12-03 16:53:46 -0800
commite670c428ff0db298a2392c05bfd310e3e4d9c675 (patch)
tree8f1055ee069552d8aa6d7a9f1b027d301262715d
parentfdb871aacca844cc6458cfa684be890f0f532d88 (diff)
downloadlinux-linaro-stable-e670c428ff0db298a2392c05bfd310e3e4d9c675.tar.gz
arm64: Consolidate hotplug notifier for instruction emulation
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>
-rw-r--r--arch/arm64/include/asm/cputype.h2
-rw-r--r--arch/arm64/kernel/armv8_deprecated.c125
2 files changed, 79 insertions, 48 deletions
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index ee6403df9fe4..68732e9a02fb 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 c363671d7509..68b955e1fd99 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;