From: Christophe Leroy <christophe.leroy@c-s.fr> To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au> Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits. Date: Tue, 14 Jan 2020 15:04:56 +0000 (UTC) [thread overview] Message-ID: <9e6aebaaf0702c3cbc199278d920f368c95af18e.1579014273.git.christophe.leroy@c-s.fr> (raw) Reorder Linux PTE bits to (almost) match Hash PTE bits. RW Kernel : PP = 00 RO Kernel : PP = 00 RW User : PP = 01 RO User : PP = 11 So naturally, we should have _PAGE_USER = 0x001 _PAGE_RW = 0x002 Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which both are software only bits. Switch _PAGE_USER and _PAGE_PRESET Switch _PAGE_RW and _PAGE_HASHPTE This allows to remove a few insns. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/include/asm/book3s/32/hash.h | 8 ++++---- arch/powerpc/kernel/head_32.S | 9 +++------ arch/powerpc/mm/book3s32/hash_low.S | 14 ++++++-------- 3 files changed, 13 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/hash.h b/arch/powerpc/include/asm/book3s/32/hash.h index 2a0a467d2985..34a7215ae81e 100644 --- a/arch/powerpc/include/asm/book3s/32/hash.h +++ b/arch/powerpc/include/asm/book3s/32/hash.h @@ -17,9 +17,9 @@ * updating the accessed and modified bits in the page table tree. */ -#define _PAGE_PRESENT 0x001 /* software: pte contains a translation */ -#define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */ -#define _PAGE_USER 0x004 /* usermode access allowed */ +#define _PAGE_USER 0x001 /* usermode access allowed */ +#define _PAGE_RW 0x002 /* software: user write access allowed */ +#define _PAGE_PRESENT 0x004 /* software: pte contains a translation */ #define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */ #define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */ #define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */ @@ -27,7 +27,7 @@ #define _PAGE_DIRTY 0x080 /* C: page changed */ #define _PAGE_ACCESSED 0x100 /* R: page referenced */ #define _PAGE_EXEC 0x200 /* software: exec allowed */ -#define _PAGE_RW 0x400 /* software: user write access allowed */ +#define _PAGE_HASHPTE 0x400 /* hash_page has made an HPTE for this pte */ #define _PAGE_SPECIAL 0x800 /* software: Special page */ #ifdef CONFIG_PTE_64BIT diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index 4a24f8f026c7..df31998abc2a 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -306,7 +306,7 @@ DataAccess: #endif bne 1f /* if not, try to put a PTE */ mfspr r4,SPRN_DAR /* into the hash table */ - rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */ + rlwinm r3,r10,32-24,30,30 /* DSISR_STORE -> _PAGE_RW */ BEGIN_MMU_FTR_SECTION bl hash_page END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) @@ -437,7 +437,6 @@ InstructionTLBMiss: andc. r1,r1,r0 /* check access & ~permission */ bne- InstructionAddressInvalid /* return if access not permitted */ /* Convert linux-style PTE to low word of PPC-style PTE */ - rlwimi r0,r0,32-2,31,31 /* _PAGE_USER -> PP lsb */ ori r1, r1, 0xe06 /* clear out reserved bits */ andc r1, r0, r1 /* PP = user? 1 : 0 */ BEGIN_FTR_SECTION @@ -505,9 +504,8 @@ DataLoadTLBMiss: * we would need to update the pte atomically with lwarx/stwcx. */ /* Convert linux-style PTE to low word of PPC-style PTE */ - rlwinm r1,r0,32-9,30,30 /* _PAGE_RW -> PP msb */ - rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */ - rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */ + rlwinm r1,r0,0,30,30 /* _PAGE_RW -> PP msb */ + rlwimi r0,r0,1,30,30 /* _PAGE_USER -> PP msb */ ori r1,r1,0xe04 /* clear out reserved bits */ andc r1,r0,r1 /* PP = user? rw? 1: 3: 0 */ BEGIN_FTR_SECTION @@ -585,7 +583,6 @@ DataStoreTLBMiss: * we would need to update the pte atomically with lwarx/stwcx. */ /* Convert linux-style PTE to low word of PPC-style PTE */ - rlwimi r0,r0,32-2,31,31 /* _PAGE_USER -> PP lsb */ li r1,0xe06 /* clear out reserved bits & PP msb */ andc r1,r0,r1 /* PP = user? 1: 0 */ BEGIN_FTR_SECTION diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S index 8bbbd9775c8a..b83ad67c218f 100644 --- a/arch/powerpc/mm/book3s32/hash_low.S +++ b/arch/powerpc/mm/book3s32/hash_low.S @@ -35,7 +35,7 @@ mmu_hash_lock: /* * 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_RW (0x002) 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. * @@ -69,7 +69,7 @@ _GLOBAL(hash_page) blt+ 112f /* assume user more likely */ lis r5, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ addi r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */ - rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */ + rlwimi r3,r9,32-14,31,31 /* MSR_PR -> _PAGE_USER */ 112: #ifndef CONFIG_PTE_64BIT rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */ @@ -94,7 +94,7 @@ _GLOBAL(hash_page) #else rlwimi r8,r4,23,20,28 /* compute pte address */ #endif - rlwinm r0,r3,32-3,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */ + rlwinm r0,r3,6,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */ ori r0,r0,_PAGE_ACCESSED|_PAGE_HASHPTE /* @@ -304,11 +304,9 @@ Hash_msk = (((1 << Hash_bits) - 1) * 64) _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 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 */ - rlwimi r5,r5,32-2,31,31 /* _PAGE_USER -> PP lsb */ + and r8,r5,r0 /* writable if _RW & _DIRTY */ + rlwimi r5,r5,1,30,30 /* _PAGE_USER -> PP msb */ ori r8,r8,0xe04 /* clear out reserved bits */ andc r8,r5,r8 /* PP = user? (rw&dirty? 1: 3): 0 */ BEGIN_FTR_SECTION @@ -560,7 +558,7 @@ _GLOBAL(flush_hash_pages) 33: lwarx r8,0,r5 /* fetch the pte flags word */ andi. r0,r8,_PAGE_HASHPTE beq 8f /* done if HASHPTE is already clear */ - rlwinm r8,r8,0,31,29 /* clear HASHPTE bit */ + rlwinm r8,r8,0,~_PAGE_HASHPTE /* clear HASHPTE bit */ stwcx. r8,0,r5 /* update the pte */ bne- 33b -- 2.13.3
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@c-s.fr> To: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits. Date: Tue, 14 Jan 2020 15:04:56 +0000 (UTC) [thread overview] Message-ID: <9e6aebaaf0702c3cbc199278d920f368c95af18e.1579014273.git.christophe.leroy@c-s.fr> (raw) Reorder Linux PTE bits to (almost) match Hash PTE bits. RW Kernel : PP = 00 RO Kernel : PP = 00 RW User : PP = 01 RO User : PP = 11 So naturally, we should have _PAGE_USER = 0x001 _PAGE_RW = 0x002 Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which both are software only bits. Switch _PAGE_USER and _PAGE_PRESET Switch _PAGE_RW and _PAGE_HASHPTE This allows to remove a few insns. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/include/asm/book3s/32/hash.h | 8 ++++---- arch/powerpc/kernel/head_32.S | 9 +++------ arch/powerpc/mm/book3s32/hash_low.S | 14 ++++++-------- 3 files changed, 13 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/hash.h b/arch/powerpc/include/asm/book3s/32/hash.h index 2a0a467d2985..34a7215ae81e 100644 --- a/arch/powerpc/include/asm/book3s/32/hash.h +++ b/arch/powerpc/include/asm/book3s/32/hash.h @@ -17,9 +17,9 @@ * updating the accessed and modified bits in the page table tree. */ -#define _PAGE_PRESENT 0x001 /* software: pte contains a translation */ -#define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */ -#define _PAGE_USER 0x004 /* usermode access allowed */ +#define _PAGE_USER 0x001 /* usermode access allowed */ +#define _PAGE_RW 0x002 /* software: user write access allowed */ +#define _PAGE_PRESENT 0x004 /* software: pte contains a translation */ #define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */ #define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */ #define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */ @@ -27,7 +27,7 @@ #define _PAGE_DIRTY 0x080 /* C: page changed */ #define _PAGE_ACCESSED 0x100 /* R: page referenced */ #define _PAGE_EXEC 0x200 /* software: exec allowed */ -#define _PAGE_RW 0x400 /* software: user write access allowed */ +#define _PAGE_HASHPTE 0x400 /* hash_page has made an HPTE for this pte */ #define _PAGE_SPECIAL 0x800 /* software: Special page */ #ifdef CONFIG_PTE_64BIT diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index 4a24f8f026c7..df31998abc2a 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -306,7 +306,7 @@ DataAccess: #endif bne 1f /* if not, try to put a PTE */ mfspr r4,SPRN_DAR /* into the hash table */ - rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */ + rlwinm r3,r10,32-24,30,30 /* DSISR_STORE -> _PAGE_RW */ BEGIN_MMU_FTR_SECTION bl hash_page END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) @@ -437,7 +437,6 @@ InstructionTLBMiss: andc. r1,r1,r0 /* check access & ~permission */ bne- InstructionAddressInvalid /* return if access not permitted */ /* Convert linux-style PTE to low word of PPC-style PTE */ - rlwimi r0,r0,32-2,31,31 /* _PAGE_USER -> PP lsb */ ori r1, r1, 0xe06 /* clear out reserved bits */ andc r1, r0, r1 /* PP = user? 1 : 0 */ BEGIN_FTR_SECTION @@ -505,9 +504,8 @@ DataLoadTLBMiss: * we would need to update the pte atomically with lwarx/stwcx. */ /* Convert linux-style PTE to low word of PPC-style PTE */ - rlwinm r1,r0,32-9,30,30 /* _PAGE_RW -> PP msb */ - rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */ - rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */ + rlwinm r1,r0,0,30,30 /* _PAGE_RW -> PP msb */ + rlwimi r0,r0,1,30,30 /* _PAGE_USER -> PP msb */ ori r1,r1,0xe04 /* clear out reserved bits */ andc r1,r0,r1 /* PP = user? rw? 1: 3: 0 */ BEGIN_FTR_SECTION @@ -585,7 +583,6 @@ DataStoreTLBMiss: * we would need to update the pte atomically with lwarx/stwcx. */ /* Convert linux-style PTE to low word of PPC-style PTE */ - rlwimi r0,r0,32-2,31,31 /* _PAGE_USER -> PP lsb */ li r1,0xe06 /* clear out reserved bits & PP msb */ andc r1,r0,r1 /* PP = user? 1: 0 */ BEGIN_FTR_SECTION diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S index 8bbbd9775c8a..b83ad67c218f 100644 --- a/arch/powerpc/mm/book3s32/hash_low.S +++ b/arch/powerpc/mm/book3s32/hash_low.S @@ -35,7 +35,7 @@ mmu_hash_lock: /* * 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_RW (0x002) 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. * @@ -69,7 +69,7 @@ _GLOBAL(hash_page) blt+ 112f /* assume user more likely */ lis r5, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ addi r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */ - rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */ + rlwimi r3,r9,32-14,31,31 /* MSR_PR -> _PAGE_USER */ 112: #ifndef CONFIG_PTE_64BIT rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */ @@ -94,7 +94,7 @@ _GLOBAL(hash_page) #else rlwimi r8,r4,23,20,28 /* compute pte address */ #endif - rlwinm r0,r3,32-3,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */ + rlwinm r0,r3,6,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */ ori r0,r0,_PAGE_ACCESSED|_PAGE_HASHPTE /* @@ -304,11 +304,9 @@ Hash_msk = (((1 << Hash_bits) - 1) * 64) _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 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 */ - rlwimi r5,r5,32-2,31,31 /* _PAGE_USER -> PP lsb */ + and r8,r5,r0 /* writable if _RW & _DIRTY */ + rlwimi r5,r5,1,30,30 /* _PAGE_USER -> PP msb */ ori r8,r8,0xe04 /* clear out reserved bits */ andc r8,r5,r8 /* PP = user? (rw&dirty? 1: 3): 0 */ BEGIN_FTR_SECTION @@ -560,7 +558,7 @@ _GLOBAL(flush_hash_pages) 33: lwarx r8,0,r5 /* fetch the pte flags word */ andi. r0,r8,_PAGE_HASHPTE beq 8f /* done if HASHPTE is already clear */ - rlwinm r8,r8,0,31,29 /* clear HASHPTE bit */ + rlwinm r8,r8,0,~_PAGE_HASHPTE /* clear HASHPTE bit */ stwcx. r8,0,r5 /* update the pte */ bne- 33b -- 2.13.3
next reply other threads:[~2020-01-14 15:05 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-14 15:04 Christophe Leroy [this message] 2020-01-14 15:04 ` [PATCH] powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits Christophe Leroy
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