[PATCH v2 33/37] powerpc/32s: Add _PAGE_WRITE to supplement _PAGE_RW
From: Christophe Leroy
Date: Mon Sep 25 2023 - 14:35:21 EST
Several places, _PAGE_RW maps to write permission and don't
always imply read. To make it more clear, do as book3s/64 in
commit c7d54842deb1 ("powerpc/mm: Use _PAGE_READ to indicate
Read access") and use _PAGE_WRITE when more relevant.
For the time being _PAGE_WRITE is equivalent to _PAGE_RW but that
will change when _PAGE_READ gets added in following patches.
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/book3s/32/pgtable.h | 15 ++++++++++++---
arch/powerpc/kernel/head_book3s_32.S | 6 +++---
arch/powerpc/mm/book3s32/hash_low.S | 12 ++++++------
arch/powerpc/mm/book3s32/mmu.c | 2 +-
4 files changed, 22 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 80505915c77c..480ad6b4fd6f 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -31,6 +31,8 @@
#define _PAGE_RW 0x400 /* software: user write access allowed */
#define _PAGE_SPECIAL 0x800 /* software: Special page */
+#define _PAGE_WRITE _PAGE_RW
+
#ifdef CONFIG_PTE_64BIT
/* We never clear the high word of the pte */
#define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE)
@@ -347,7 +349,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
- pte_update(mm, addr, ptep, _PAGE_RW, 0, 0);
+ pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 0);
}
static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
@@ -406,7 +408,11 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
}
/* Generic accessors to PTE bits */
-static inline int pte_write(pte_t pte) { return !!(pte_val(pte) & _PAGE_RW);}
+static inline bool pte_write(pte_t pte)
+{
+ return !!(pte_val(pte) & _PAGE_WRITE);
+}
+
static inline int pte_read(pte_t pte) { return 1; }
static inline int pte_dirty(pte_t pte) { return !!(pte_val(pte) & _PAGE_DIRTY); }
static inline int pte_young(pte_t pte) { return !!(pte_val(pte) & _PAGE_ACCESSED); }
@@ -469,7 +475,7 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
/* Generic modifiers for PTE bits */
static inline pte_t pte_wrprotect(pte_t pte)
{
- return __pte(pte_val(pte) & ~_PAGE_RW);
+ return __pte(pte_val(pte) & ~_PAGE_WRITE);
}
static inline pte_t pte_exprotect(pte_t pte)
@@ -499,6 +505,9 @@ static inline pte_t pte_mkpte(pte_t pte)
static inline pte_t pte_mkwrite_novma(pte_t pte)
{
+ /*
+ * write implies read, hence set both
+ */
return __pte(pte_val(pte) | _PAGE_RW);
}
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 6764b98ca360..615d429d7bd1 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -503,9 +503,9 @@ DataLoadTLBMiss:
andc. r1,r1,r0 /* check access & ~permission */
bne- DataAddressInvalid /* return if access not permitted */
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwinm r1,r0,32-9,30,30 /* _PAGE_RW -> PP msb */
+ rlwinm r1,r0,32-9,30,30 /* _PAGE_WRITE -> PP msb */
rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
- rlwimi r1,r0,32-3,24,24 /* _PAGE_RW -> _PAGE_DIRTY */
+ rlwimi r1,r0,32-3,24,24 /* _PAGE_WRITE -> _PAGE_DIRTY */
rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
xori r1,r1,_PAGE_DIRTY /* clear dirty when not rw */
ori r1,r1,0xe04 /* clear out reserved bits */
@@ -689,7 +689,7 @@ hash_page_dsi:
mfdar r4
mfsrr0 r5
mfsrr1 r9
- rlwinm r3, r3, 32 - 15, _PAGE_RW /* DSISR_STORE -> _PAGE_RW */
+ rlwinm r3, r3, 32 - 15, _PAGE_WRITE /* DSISR_STORE -> _PAGE_WRITE */
bl hash_page
mfspr r10, SPRN_SPRG_THREAD
restore_regs_thread r10
diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 8b804e1a9fa4..acb0584c174c 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -37,7 +37,7 @@
/*
* Load a PTE into the hash table, if possible.
* The address is in r4, and r3 contains an access flag:
- * _PAGE_RW (0x400) if a write.
+ * _PAGE_WRITE (0x400) if a write.
* r9 contains the SRR1 value, from which we use the MSR_PR bit.
* SPRG_THREAD contains the physical address of the current task's thread.
*
@@ -113,15 +113,15 @@ _GLOBAL(hash_page)
lwarx r6,0,r8 /* get linux-style pte, flag word */
#ifdef CONFIG_PPC_KUAP
mfsrin r5,r4
- rlwinm r0,r9,28,_PAGE_RW /* MSR[PR] => _PAGE_RW */
- rlwinm r5,r5,12,_PAGE_RW /* Ks => _PAGE_RW */
+ rlwinm r0,r9,28,_PAGE_WRITE /* MSR[PR] => _PAGE_WRITE */
+ rlwinm r5,r5,12,_PAGE_WRITE /* Ks => _PAGE_WRITE */
andc r5,r5,r0 /* Ks & ~MSR[PR] */
- andc r5,r6,r5 /* Clear _PAGE_RW when Ks = 1 && MSR[PR] = 0 */
+ andc r5,r6,r5 /* Clear _PAGE_WRITE when Ks = 1 && MSR[PR] = 0 */
andc. r5,r3,r5 /* check access & ~permission */
#else
andc. r5,r3,r6 /* check access & ~permission */
#endif
- rlwinm r0,r3,32-3,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */
+ rlwinm r0,r3,32-3,24,24 /* _PAGE_WRITE access -> _PAGE_DIRTY */
ori r0,r0,_PAGE_ACCESSED|_PAGE_HASHPTE
#ifdef CONFIG_SMP
bne- .Lhash_page_out /* return if access not permitted */
@@ -307,7 +307,7 @@ Hash_msk = (((1 << Hash_bits) - 1) * 64)
__REF
_GLOBAL(create_hpte)
/* Convert linux-style PTE (r5) to low word of PPC-style PTE (r8) */
- rlwinm r8,r5,32-9,30,30 /* _PAGE_RW -> PP msb */
+ rlwinm r8,r5,32-9,30,30 /* _PAGE_WRITE -> PP msb */
rlwinm r0,r5,32-6,30,30 /* _PAGE_DIRTY -> PP msb */
and r8,r8,r0 /* writable if _RW & _DIRTY */
rlwimi r5,r5,32-1,30,30 /* _PAGE_USER -> PP msb */
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index d1041c946ce2..06bf0972792d 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -277,7 +277,7 @@ void __init setbat(int index, unsigned long virt, phys_addr_t phys,
/* Do DBAT first */
wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE
| _PAGE_COHERENT | _PAGE_GUARDED);
- wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX;
+ wimgxpp |= (flags & _PAGE_WRITE)? BPP_RW: BPP_RX;
bat[1].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */
bat[1].batl = BAT_PHYS_ADDR(phys) | wimgxpp;
if (!is_kernel_addr(virt))
--
2.41.0