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arm64: Consolidate hotplug notifier for instruction emulation

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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>
This commit is contained in:
Suzuki K. Poulose 2015-01-21 12:43:10 +00:00 committed by Catalin Marinas
parent 04597a65c5
commit 736d474f0f
2 changed files with 79 additions and 48 deletions
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2
arch/arm64/include/asm/cputype.h
View file

@ -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__
/*

125
arch/arm64/kernel/armv8_deprecated.c
View file

@ -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 @@ static int cp15barrier_handler(struct pt_regs *regs, u32 instr)
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;