powerpc/32s: Add _PAGE_WRITE to supplement _PAGE_RW

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@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/5798782869fe4d2698f104948dabd17657b89395.1695659959.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 80505915c77cf01e77f2f0dda192313eaa2543a7..480ad6b4fd6fe315843eb83c40b29371a654b199 100644 (file)
--- 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 6764b98ca360fe048f7375c1b4e6209376a94eec..615d429d7bd10ec1b2155197ba35f82e9e5e690f 100644 (file)
--- 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 8b804e1a9fa4485fd82f87f6c97cef82e1a026dc..acb0584c174cb8f4f2c6556bb0330b2068b6449c 100644 (file)
--- 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 d1041c946ce200cd5d499112bbfa6a0c0c436419..5445587bfe8418a5ea40cbde0c525d3c462eab4a 100644 (file)
--- 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))