[PATCH v2 7/9] arm64: armv8_deprecated move emulation functions

Mark Rutland
2022-10-19T15:08:22Z

Subsequent patches will rework the logic in armv8_deprecated.c.

In preparation for subsequent changes, this patch moves the emulation
logic earlier in the file, and moves the infrastructure later in the
file. This will make subsequent diffs simpler and easier to read.

This is purely a move. There should be no functional change as a result
of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/kernel/armv8_deprecated.c | 394 +++++++++++++--------------
1 file changed, 197 insertions(+), 197 deletions(-)

diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index 2a75e20a3913..792b89929c04 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -52,203 +52,6 @@ struct insn_emulation {
int max;
};

-static LIST_HEAD(insn_emulation);
-static int nr_insn_emulated __initdata;
-static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
-static DEFINE_MUTEX(insn_emulation_mutex);
-
-static void register_emulation_hooks(struct insn_emulation *insn)
-{
- struct undef_hook *hook;
-
- BUG_ON(!insn->hooks);
-
- for (hook = insn->hooks; hook->instr_mask; hook++)
- register_undef_hook(hook);
-
- pr_notice("Registered %s emulation handler\n", insn->name);
-}
-
-static void remove_emulation_hooks(struct insn_emulation *insn)
-{
- struct undef_hook *hook;
-
- BUG_ON(!insn->hooks);
-
- for (hook = insn->hooks; hook->instr_mask; hook++)
- unregister_undef_hook(hook);
-
- pr_notice("Removed %s emulation handler\n", insn->name);
-}
-
-static void enable_insn_hw_mode(void *data)
-{
- struct insn_emulation *insn = (struct insn_emulation *)data;
- if (insn->set_hw_mode)
- insn->set_hw_mode(true);
-}
-
-static void disable_insn_hw_mode(void *data)
-{
- struct insn_emulation *insn = (struct insn_emulation *)data;
- if (insn->set_hw_mode)
- insn->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->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 int 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->set_hw_mode && insn->set_hw_mode(enable)) {
- pr_warn("CPU[%u] cannot support the emulation of %s",
- cpu, insn->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)
-{
- int ret = 0;
-
- switch (prev) {
- case INSN_UNDEF: /* Nothing to be done */
- break;
- case INSN_EMULATE:
- remove_emulation_hooks(insn);
- break;
- case INSN_HW:
- if (!run_all_cpu_set_hw_mode(insn, false))
- pr_notice("Disabled %s support\n", insn->name);
- break;
- }
-
- switch (insn->current_mode) {
- case INSN_UNDEF:
- break;
- case INSN_EMULATE:
- register_emulation_hooks(insn);
- break;
- case INSN_HW:
- ret = run_all_cpu_set_hw_mode(insn, true);
- if (!ret)
- pr_notice("Enabled %s support\n", insn->name);
- break;
- }
-
- return ret;
-}
-
-static void __init register_insn_emulation(struct insn_emulation *insn)
-{
- unsigned long flags;
-
- insn->min = INSN_UNDEF;
-
- switch (insn->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:
- insn->current_mode = INSN_UNDEF;
- insn->max = INSN_EMULATE;
- break;
- }
-
- raw_spin_lock_irqsave(&insn_emulation_lock, flags);
- list_add(&insn->node, &insn_emulation);
- nr_insn_emulated++;
- raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
-
- /* Register any handlers if required */
- update_insn_emulation_mode(insn, INSN_UNDEF);
-}
-
-static int emulation_proc_handler(struct ctl_table *table, int write,
- void *buffer, size_t *lenp,
- loff_t *ppos)
-{
- int ret = 0;
- struct insn_emulation *insn = container_of(table->data, struct insn_emulation, current_mode);
- enum insn_emulation_mode prev_mode = insn->current_mode;
-
- mutex_lock(&insn_emulation_mutex);
- ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-
- if (ret || !write || prev_mode == insn->current_mode)
- goto ret;
-
- ret = update_insn_emulation_mode(insn, prev_mode);
- if (ret) {
- /* Mode change failed, revert to previous mode. */
- insn->current_mode = prev_mode;
- update_insn_emulation_mode(insn, INSN_UNDEF);
- }
-ret:
- mutex_unlock(&insn_emulation_mutex);
- return ret;
-}
-
-static void __init register_insn_emulation_sysctl(void)
-{
- unsigned long flags;
- int i = 0;
- struct insn_emulation *insn;
- struct ctl_table *insns_sysctl, *sysctl;
-
- insns_sysctl = kcalloc(nr_insn_emulated + 1, sizeof(*sysctl),
- GFP_KERNEL);
- if (!insns_sysctl)
- return;
-
- raw_spin_lock_irqsave(&insn_emulation_lock, flags);
- list_for_each_entry(insn, &insn_emulation, node) {
- sysctl = &insns_sysctl[i];
-
- sysctl->mode = 0644;
- sysctl->maxlen = sizeof(int);
-
- sysctl->procname = insn->name;
- sysctl->data = &insn->current_mode;
- sysctl->extra1 = &insn->min;
- sysctl->extra2 = &insn->max;
- sysctl->proc_handler = emulation_proc_handler;
- i++;
- }
- raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
-
- register_sysctl("abi", insns_sysctl);
-}
-
/*
* Implement emulation of the SWP/SWPB instructions using load-exclusive and
* store-exclusive.
@@ -602,6 +405,203 @@ static struct insn_emulation insn_setend = {
.set_hw_mode = setend_set_hw_mode,
};

+static LIST_HEAD(insn_emulation);
+static int nr_insn_emulated __initdata;
+static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
+static DEFINE_MUTEX(insn_emulation_mutex);
+
+static void register_emulation_hooks(struct insn_emulation *insn)
+{
+ struct undef_hook *hook;
+
+ BUG_ON(!insn->hooks);
+
+ for (hook = insn->hooks; hook->instr_mask; hook++)
+ register_undef_hook(hook);
+
+ pr_notice("Registered %s emulation handler\n", insn->name);
+}
+
+static void remove_emulation_hooks(struct insn_emulation *insn)
+{
+ struct undef_hook *hook;
+
+ BUG_ON(!insn->hooks);
+
+ for (hook = insn->hooks; hook->instr_mask; hook++)
+ unregister_undef_hook(hook);
+
+ pr_notice("Removed %s emulation handler\n", insn->name);
+}
+
+static void enable_insn_hw_mode(void *data)
+{
+ struct insn_emulation *insn = (struct insn_emulation *)data;
+ if (insn->set_hw_mode)
+ insn->set_hw_mode(true);
+}
+
+static void disable_insn_hw_mode(void *data)
+{
+ struct insn_emulation *insn = (struct insn_emulation *)data;
+ if (insn->set_hw_mode)
+ insn->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->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 int 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->set_hw_mode && insn->set_hw_mode(enable)) {
+ pr_warn("CPU[%u] cannot support the emulation of %s",
+ cpu, insn->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)
+{
+ int ret = 0;
+
+ switch (prev) {
+ case INSN_UNDEF: /* Nothing to be done */
+ break;
+ case INSN_EMULATE:
+ remove_emulation_hooks(insn);
+ break;
+ case INSN_HW:
+ if (!run_all_cpu_set_hw_mode(insn, false))
+ pr_notice("Disabled %s support\n", insn->name);
+ break;
+ }
+
+ switch (insn->current_mode) {
+ case INSN_UNDEF:
+ break;
+ case INSN_EMULATE:
+ register_emulation_hooks(insn);
+ break;
+ case INSN_HW:
+ ret = run_all_cpu_set_hw_mode(insn, true);
+ if (!ret)
+ pr_notice("Enabled %s support\n", insn->name);
+ break;
+ }
+
+ return ret;
+}
+
+static void __init register_insn_emulation(struct insn_emulation *insn)
+{
+ unsigned long flags;
+
+ insn->min = INSN_UNDEF;
+
+ switch (insn->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:
+ insn->current_mode = INSN_UNDEF;
+ insn->max = INSN_EMULATE;
+ break;
+ }
+
+ raw_spin_lock_irqsave(&insn_emulation_lock, flags);
+ list_add(&insn->node, &insn_emulation);
+ nr_insn_emulated++;
+ raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
+
+ /* Register any handlers if required */
+ update_insn_emulation_mode(insn, INSN_UNDEF);
+}
+
+static int emulation_proc_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret = 0;
+ struct insn_emulation *insn = container_of(table->data, struct insn_emulation, current_mode);
+ enum insn_emulation_mode prev_mode = insn->current_mode;
+
+ mutex_lock(&insn_emulation_mutex);
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+ if (ret || !write || prev_mode == insn->current_mode)
+ goto ret;
+
+ ret = update_insn_emulation_mode(insn, prev_mode);
+ if (ret) {
+ /* Mode change failed, revert to previous mode. */
+ insn->current_mode = prev_mode;
+ update_insn_emulation_mode(insn, INSN_UNDEF);
+ }
+ret:
+ mutex_unlock(&insn_emulation_mutex);
+ return ret;
+}
+
+static void __init register_insn_emulation_sysctl(void)
+{
+ unsigned long flags;
+ int i = 0;
+ struct insn_emulation *insn;
+ struct ctl_table *insns_sysctl, *sysctl;
+
+ insns_sysctl = kcalloc(nr_insn_emulated + 1, sizeof(*sysctl),
+ GFP_KERNEL);
+ if (!insns_sysctl)
+ return;
+
+ raw_spin_lock_irqsave(&insn_emulation_lock, flags);
+ list_for_each_entry(insn, &insn_emulation, node) {
+ sysctl = &insns_sysctl[i];
+
+ sysctl->mode = 0644;
+ sysctl->maxlen = sizeof(int);
+
+ sysctl->procname = insn->name;
+ sysctl->data = &insn->current_mode;
+ sysctl->extra1 = &insn->min;
+ sysctl->extra2 = &insn->max;
+ sysctl->proc_handler = emulation_proc_handler;
+ i++;
+ }
+ raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
+
+ register_sysctl("abi", insns_sysctl);
+}
+
/*
* Invoked as core_initcall, which guarantees that the instruction
* emulation is ready for userspace.