Subject: [PATCH v3 16/41] powerpc/book3s64/pkeys: Use MMU_FTR_PKEY instead of pkey_disabled static key

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Wed, 10 Jun 2020 15:21:39 +0530

Instead of pkey_disabled static key use mmu feature MMU_FTR_PKEY.

Signed-off-by: Aneesh Kumar K.V <[email-masked]>
---
 arch/powerpc/include/asm/book3s/64/pkeys.h |  2 +-
 arch/powerpc/include/asm/pkeys.h           | 14 ++++++--------
 arch/powerpc/mm/book3s64/pkeys.c           | 16 +++++++---------
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h
index 8174662a9173..5b178139f3c0 100644
--- a/arch/powerpc/include/asm/book3s/64/pkeys.h
+++ b/arch/powerpc/include/asm/book3s/64/pkeys.h
@@ -7,7 +7,7 @@
 
 static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return 0x0UL;
 
 	if (radix_enabled())
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 09fbaa409ac4..b1d448c53209 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -11,7 +11,6 @@
 #include <linux/jump_label.h>
 #include <asm/firmware.h>
 
-DECLARE_STATIC_KEY_FALSE(pkey_disabled);
 extern int max_pkey;
 extern u32 reserved_allocation_mask; /* bits set for reserved keys */
 
@@ -38,7 +37,7 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey)
 
 static inline int vma_pkey(struct vm_area_struct *vma)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return 0;
 	return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
 }
@@ -93,9 +92,8 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
 	u32 all_pkeys_mask = (u32)(~(0x0));
 	int ret;
 
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return -1;
-
 	/*
 	 * Are we out of pkeys? We must handle this specially because ffz()
 	 * behavior is undefined if there are no zeros.
@@ -111,7 +109,7 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
 
 static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return -1;
 
 	if (!mm_pkey_is_allocated(mm, pkey))
@@ -132,7 +130,7 @@ extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
 static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
 					      int prot, int pkey)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return 0;
 
 	/*
@@ -150,7 +148,7 @@ extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 					    unsigned long init_val)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return -EINVAL;
 
 	/*
@@ -167,7 +165,7 @@ static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 
 static inline bool arch_pkeys_enabled(void)
 {
-	return !static_branch_likely(&pkey_disabled);
+	return mmu_has_feature(MMU_FTR_PKEY);
 }
 
 extern void pkey_mm_init(struct mm_struct *mm);
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index fed4f159011b..810118123e70 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -13,7 +13,6 @@
 #include <linux/of_fdt.h>

-DEFINE_STATIC_KEY_FALSE(pkey_disabled);
 DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled);
 int  max_pkey;			/* Maximum key value supported */
 /*
@@ -114,7 +113,6 @@ void __init pkey_early_init_devtree(void)
 	pkeys_total = scan_pkey_feature();
 	if (!pkeys_total) {
 		/* No support for pkey. Mark it disabled */
-		static_branch_enable(&pkey_disabled);
 		return;
 	}
 
@@ -202,7 +200,7 @@ void __init pkey_early_init_devtree(void)
 
 void pkey_mm_init(struct mm_struct *mm)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return;
 	mm_pkey_allocation_map(mm) = initial_allocation_mask;
 	mm->context.execute_only_pkey = execute_only_key;
@@ -306,7 +304,7 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 
 void thread_pkey_regs_save(struct thread_struct *thread)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return;
 
 	/*
@@ -320,7 +318,7 @@ void thread_pkey_regs_save(struct thread_struct *thread)
 void thread_pkey_regs_restore(struct thread_struct *new_thread,
 			      struct thread_struct *old_thread)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return;
 
 	if (old_thread->amr != new_thread->amr)
@@ -333,7 +331,7 @@ void thread_pkey_regs_restore(struct thread_struct *new_thread,
 
 void thread_pkey_regs_init(struct thread_struct *thread)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return;
 
 	thread->amr   = default_amr;
@@ -408,7 +406,7 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
 
 bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return true;
 
 	return pkey_access_permitted(pte_to_pkey_bits(pte), write, execute);
@@ -425,7 +423,7 @@ bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
 bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
 			       bool execute, bool foreign)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return true;
 	/*
 	 * Do not enforce our key-permissions on a foreign vma.
@@ -438,7 +436,7 @@ bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
 
 void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm)
 {
-	if (static_branch_likely(&pkey_disabled))
+	if (!mmu_has_feature(MMU_FTR_PKEY))
 		return;
 
 	/* Duplicate the oldmm pkey state in mm: */
-- 
2.26.2