arm64: armv8_deprecated: fold ops into insn_emulation

The code for emulating deprecated instructions has two related
structures: struct insn_emulation_ops and struct insn_emulation, where
each struct insn_emulation_ops is associated 1-1 with a struct
insn_emulation.

It would be simpler to combine the two into a single structure, removing
the need for (unconditional) dynamic allocation at boot time, and
simplifying some runtime pointer chasing.

This patch merges the two structures together.

There should be no functional change as a result of this patch.
Signed-off-by: NMark 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>
Link: https://lore.kernel.org/r/20221019144123.612388-7-mark.rutland@arm.comSigned-off-by: NWill Deacon <will@kernel.org>

arch/arm64/kernel/armv8_deprecated.c

@@ -41,16 +41,12 @@ enum legacy_insn_status {
 	INSN_OBSOLETE,
 };
 
-struct insn_emulation_ops {
+struct insn_emulation {
 	const char			*name;
+	struct list_head		node;
 	enum legacy_insn_status		status;
 	struct undef_hook		*hooks;
 	int				(*set_hw_mode)(bool enable);
-};
-
-struct insn_emulation {
-	struct list_head node;
-	struct insn_emulation_ops *ops;
 	int current_mode;
 	int min;
 	int max;
@@ -61,48 +57,48 @@ 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_ops *ops)
+static void register_emulation_hooks(struct insn_emulation *insn)
 {
 	struct undef_hook *hook;
 
-	BUG_ON(!ops->hooks);
+	BUG_ON(!insn->hooks);
 
-	for (hook = ops->hooks; hook->instr_mask; hook++)
+	for (hook = insn->hooks; hook->instr_mask; hook++)
 		register_undef_hook(hook);
 
-	pr_notice("Registered %s emulation handler\n", ops->name);
+	pr_notice("Registered %s emulation handler\n", insn->name);
 }
 
-static void remove_emulation_hooks(struct insn_emulation_ops *ops)
+static void remove_emulation_hooks(struct insn_emulation *insn)
 {
 	struct undef_hook *hook;
 
-	BUG_ON(!ops->hooks);
+	BUG_ON(!insn->hooks);
 
-	for (hook = ops->hooks; hook->instr_mask; hook++)
+	for (hook = insn->hooks; hook->instr_mask; hook++)
 		unregister_undef_hook(hook);
 
-	pr_notice("Removed %s emulation handler\n", ops->name);
+	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->ops->set_hw_mode)
-		insn->ops->set_hw_mode(true);
+	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->ops->set_hw_mode)
-		insn->ops->set_hw_mode(false);
+	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->ops->set_hw_mode)
+	if (!insn->set_hw_mode)
 		return -EINVAL;
 	if (enable)
 		on_each_cpu(enable_insn_hw_mode, (void *)insn, true);
@@ -126,9 +122,9 @@ static int run_all_insn_set_hw_mode(unsigned int cpu)
 	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)) {
+		if (insn->set_hw_mode && insn->set_hw_mode(enable)) {
 			pr_warn("CPU[%u] cannot support the emulation of %s",
-				cpu, insn->ops->name);
+				cpu, insn->name);
 			rc = -EINVAL;
 		}
 	}
@@ -145,11 +141,11 @@ static int update_insn_emulation_mode(struct insn_emulation *insn,
 	case INSN_UNDEF: /* Nothing to be done */
 		break;
 	case INSN_EMULATE:
-		remove_emulation_hooks(insn->ops);
+		remove_emulation_hooks(insn);
 		break;
 	case INSN_HW:
 		if (!run_all_cpu_set_hw_mode(insn, false))
-			pr_notice("Disabled %s support\n", insn->ops->name);
+			pr_notice("Disabled %s support\n", insn->name);
 		break;
 	}
 
@@ -157,31 +153,25 @@ static int update_insn_emulation_mode(struct insn_emulation *insn,
 	case INSN_UNDEF:
 		break;
 	case INSN_EMULATE:
-		register_emulation_hooks(insn->ops);
+		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->ops->name);
+			pr_notice("Enabled %s support\n", insn->name);
 		break;
 	}
 
 	return ret;
 }
 
-static void __init register_insn_emulation(struct insn_emulation_ops *ops)
+static void __init register_insn_emulation(struct insn_emulation *insn)
 {
 	unsigned long flags;
-	struct insn_emulation *insn;
-
-	insn = kzalloc(sizeof(*insn), GFP_KERNEL);
-	if (!insn)
-		return;
 
-	insn->ops = ops;
 	insn->min = INSN_UNDEF;
 
-	switch (ops->status) {
+	switch (insn->status) {
 	case INSN_DEPRECATED:
 		insn->current_mode = INSN_EMULATE;
 		/* Disable the HW mode if it was turned on at early boot time */
@@ -247,7 +237,7 @@ static void __init register_insn_emulation_sysctl(void)
 		sysctl->mode = 0644;
 		sysctl->maxlen = sizeof(int);
 
-		sysctl->procname = insn->ops->name;
+		sysctl->procname = insn->name;
 		sysctl->data = &insn->current_mode;
 		sysctl->extra1 = &insn->min;
 		sysctl->extra2 = &insn->max;
@@ -445,7 +435,7 @@ static struct undef_hook swp_hooks[] = {
 	{ }
 };
 
-static struct insn_emulation_ops swp_ops = {
+static struct insn_emulation insn_swp = {
 	.name = "swp",
 	.status = INSN_OBSOLETE,
 	.hooks = swp_hooks,
@@ -532,7 +522,7 @@ static struct undef_hook cp15_barrier_hooks[] = {
 	{ }
 };
 
-static struct insn_emulation_ops cp15_barrier_ops = {
+static struct insn_emulation insn_cp15_barrier = {
 	.name = "cp15_barrier",
 	.status = INSN_DEPRECATED,
 	.hooks = cp15_barrier_hooks,
@@ -605,7 +595,7 @@ static struct undef_hook setend_hooks[] = {
 	{}
 };
 
-static struct insn_emulation_ops setend_ops = {
+static struct insn_emulation insn_setend = {
 	.name = "setend",
 	.status = INSN_DEPRECATED,
 	.hooks = setend_hooks,
@@ -619,14 +609,14 @@ static struct insn_emulation_ops setend_ops = {
 static int __init armv8_deprecated_init(void)
 {
 	if (IS_ENABLED(CONFIG_SWP_EMULATION))
-		register_insn_emulation(&swp_ops);
+		register_insn_emulation(&insn_swp);
 
 	if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
-		register_insn_emulation(&cp15_barrier_ops);
+		register_insn_emulation(&insn_cp15_barrier);
 
 	if (IS_ENABLED(CONFIG_SETEND_EMULATION)) {
 		if (system_supports_mixed_endian_el0())
-			register_insn_emulation(&setend_ops);
+			register_insn_emulation(&insn_setend);
 		else
 			pr_info("setend instruction emulation is not supported on this system\n");
 	}