From: Christophe Leroy <christophe.leroy@csgroup.eu> 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 v4 37/45] powerpc/8xx: Refactor kernel address boundary comparison Date: Tue, 19 May 2020 05:49:20 +0000 (UTC) [thread overview] Message-ID: <6312575d06a8813105e6564a3b12e1d373aa1b2f.1589866984.git.christophe.leroy@csgroup.eu> (raw) In-Reply-To: <cover.1589866984.git.christophe.leroy@csgroup.eu> Now that linear and IMMR dedicated TLB handling is gone, kernel boundary address comparison is similar in ITLB miss handler and in DTLB miss handler. Create a macro named compare_to_kernel_boundary. When TASK_SIZE is strictly below 0x80000000 and PAGE_OFFSET is above 0x80000000, it is enough to compare to 0x8000000, and this can be done with a single instruction. Using not. instruction, we get to use 'blt' conditional branch as when doing a regular comparison: 0x00000000 <= addr <= 0x7fffffff ==> 0xffffffff >= NOT(addr) >= 0x80000000 The above test corresponds to a 'blt' Otherwise, do a regular comparison using two instructions. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/head_8xx.S | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 9f3f7f3d03a7..9a117b9f0998 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -32,10 +32,15 @@ #include "head_32.h" +.macro compare_to_kernel_boundary scratch, addr #if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000 /* By simply checking Address >= 0x80000000, we know if its a kernel address */ -#define SIMPLE_KERNEL_ADDRESS 1 + not. \scratch, \addr +#else + rlwinm \scratch, \addr, 16, 0xfff8 + cmpli cr0, \scratch, PAGE_OFFSET@h #endif +.endm /* * We need an ITLB miss handler for kernel addresses if: @@ -209,20 +214,11 @@ InstructionTLBMiss: mtspr SPRN_MD_EPN, r10 #ifdef ITLB_MISS_KERNEL mfcr r11 -#if defined(SIMPLE_KERNEL_ADDRESS) - cmpi cr0, r10, 0 /* Address >= 0x80000000 */ -#else - rlwinm r10, r10, 16, 0xfff8 - cmpli cr0, r10, PAGE_OFFSET@h -#endif + compare_to_kernel_boundary r10, r10 #endif mfspr r10, SPRN_M_TWB /* Get level 1 table */ #ifdef ITLB_MISS_KERNEL -#if defined(SIMPLE_KERNEL_ADDRESS) - bge+ 3f -#else blt+ 3f -#endif rlwinm r10, r10, 0, 20, 31 oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha 3: @@ -288,9 +284,7 @@ DataStoreTLBMiss: * kernel page tables. */ mfspr r10, SPRN_MD_EPN - rlwinm r10, r10, 16, 0xfff8 - cmpli cr0, r10, PAGE_OFFSET@h - + compare_to_kernel_boundary r10, r10 mfspr r10, SPRN_M_TWB /* Get level 1 table */ blt+ 3f rlwinm r10, r10, 0, 20, 31 -- 2.25.0
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@csgroup.eu> 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 v4 37/45] powerpc/8xx: Refactor kernel address boundary comparison Date: Tue, 19 May 2020 05:49:20 +0000 (UTC) [thread overview] Message-ID: <6312575d06a8813105e6564a3b12e1d373aa1b2f.1589866984.git.christophe.leroy@csgroup.eu> (raw) In-Reply-To: <cover.1589866984.git.christophe.leroy@csgroup.eu> Now that linear and IMMR dedicated TLB handling is gone, kernel boundary address comparison is similar in ITLB miss handler and in DTLB miss handler. Create a macro named compare_to_kernel_boundary. When TASK_SIZE is strictly below 0x80000000 and PAGE_OFFSET is above 0x80000000, it is enough to compare to 0x8000000, and this can be done with a single instruction. Using not. instruction, we get to use 'blt' conditional branch as when doing a regular comparison: 0x00000000 <= addr <= 0x7fffffff ==> 0xffffffff >= NOT(addr) >= 0x80000000 The above test corresponds to a 'blt' Otherwise, do a regular comparison using two instructions. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/head_8xx.S | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 9f3f7f3d03a7..9a117b9f0998 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -32,10 +32,15 @@ #include "head_32.h" +.macro compare_to_kernel_boundary scratch, addr #if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000 /* By simply checking Address >= 0x80000000, we know if its a kernel address */ -#define SIMPLE_KERNEL_ADDRESS 1 + not. \scratch, \addr +#else + rlwinm \scratch, \addr, 16, 0xfff8 + cmpli cr0, \scratch, PAGE_OFFSET@h #endif +.endm /* * We need an ITLB miss handler for kernel addresses if: @@ -209,20 +214,11 @@ InstructionTLBMiss: mtspr SPRN_MD_EPN, r10 #ifdef ITLB_MISS_KERNEL mfcr r11 -#if defined(SIMPLE_KERNEL_ADDRESS) - cmpi cr0, r10, 0 /* Address >= 0x80000000 */ -#else - rlwinm r10, r10, 16, 0xfff8 - cmpli cr0, r10, PAGE_OFFSET@h -#endif + compare_to_kernel_boundary r10, r10 #endif mfspr r10, SPRN_M_TWB /* Get level 1 table */ #ifdef ITLB_MISS_KERNEL -#if defined(SIMPLE_KERNEL_ADDRESS) - bge+ 3f -#else blt+ 3f -#endif rlwinm r10, r10, 0, 20, 31 oris r10, r10, (swapper_pg_dir - PAGE_OFFSET)@ha 3: @@ -288,9 +284,7 @@ DataStoreTLBMiss: * kernel page tables. */ mfspr r10, SPRN_MD_EPN - rlwinm r10, r10, 16, 0xfff8 - cmpli cr0, r10, PAGE_OFFSET@h - + compare_to_kernel_boundary r10, r10 mfspr r10, SPRN_M_TWB /* Get level 1 table */ blt+ 3f rlwinm r10, r10, 0, 20, 31 -- 2.25.0
next prev parent reply other threads:[~2020-05-19 5:49 UTC|newest] Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-19 5:48 [PATCH v4 00/45] Use hugepages to map kernel mem on 8xx Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 01/45] powerpc/kasan: Fix error detection on memory allocation Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 02/45] powerpc/kasan: Fix issues by lowering KASAN_SHADOW_END Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 03/45] powerpc/kasan: Fix shadow pages allocation failure Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 04/45] powerpc/kasan: Remove unnecessary page table locking Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 05/45] powerpc/kasan: Refactor update of early shadow mappings Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 06/45] powerpc/kasan: Declare kasan_init_region() weak Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 07/45] powerpc/ptdump: Limit size of flags text to 1/2 chars on PPC32 Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-25 5:15 ` Michael Ellerman 2020-05-25 5:15 ` Michael Ellerman 2020-05-25 11:06 ` Christophe Leroy 2020-05-25 11:06 ` Christophe Leroy 2020-05-26 12:53 ` Michael Ellerman 2020-05-26 12:53 ` Michael Ellerman 2020-05-19 5:48 ` [PATCH v4 08/45] powerpc/ptdump: Reorder flags Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 09/45] powerpc/ptdump: Add _PAGE_COHERENT flag Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 10/45] powerpc/ptdump: Display size of BATs Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 11/45] powerpc/ptdump: Standardise display of BAT flags Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 12/45] powerpc/ptdump: Properly handle non standard page size Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 13/45] powerpc/ptdump: Handle hugepd at PGD level Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 14/45] powerpc/32s: Don't warn when mapping RO data ROX Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-25 5:40 ` Michael Ellerman 2020-05-25 5:40 ` Michael Ellerman 2020-05-19 5:48 ` [PATCH v4 15/45] powerpc/mm: Allocate static page tables for fixmap Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:48 ` [PATCH v4 16/45] powerpc/mm: Fix conditions to perform MMU specific management by blocks on PPC32 Christophe Leroy 2020-05-19 5:48 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 17/45] powerpc/mm: PTE_ATOMIC_UPDATES is only for 40x Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 18/45] powerpc/mm: Refactor pte_update() on nohash/32 Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 19/45] powerpc/mm: Refactor pte_update() on book3s/32 Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 20/45] powerpc/mm: Standardise __ptep_test_and_clear_young() params between PPC32 and PPC64 Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 21/45] powerpc/mm: Standardise pte_update() prototype " Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 22/45] powerpc/mm: Create a dedicated pte_update() for 8xx Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 23/45] powerpc/mm: Reduce hugepd size for 8M hugepages on 8xx Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 24/45] powerpc/8xx: Drop CONFIG_8xx_COPYBACK option Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 25/45] powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 26/45] powerpc/8xx: Manage 512k huge pages as standard pages Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 27/45] powerpc/8xx: Only 8M pages are hugepte pages now Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 28/45] powerpc/8xx: MM_SLICE is not needed anymore Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 29/45] powerpc/8xx: Move PPC_PIN_TLB options into 8xx Kconfig Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 30/45] powerpc/8xx: Add function to set pinned TLBs Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 31/45] powerpc/8xx: Don't set IMMR map anymore at boot Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 32/45] powerpc/8xx: Always pin TLBs at startup Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 33/45] powerpc/8xx: Drop special handling of Linear and IMMR mappings in I/D TLB handlers Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 34/45] powerpc/8xx: Remove now unused TLB miss functions Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 35/45] powerpc/8xx: Move DTLB perf handling closer Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 36/45] powerpc/mm: Don't be too strict with _etext alignment on PPC32 Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy [this message] 2020-05-19 5:49 ` [PATCH v4 37/45] powerpc/8xx: Refactor kernel address boundary comparison Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 38/45] powerpc/8xx: Add a function to early map kernel via huge pages Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 39/45] powerpc/8xx: Map IMMR with a huge page Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 40/45] powerpc/8xx: Map linear memory with huge pages Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 41/45] powerpc/8xx: Allow STRICT_KERNEL_RwX with pinned TLB Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 42/45] powerpc/8xx: Allow large TLBs with DEBUG_PAGEALLOC Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 43/45] powerpc/8xx: Implement dedicated kasan_init_region() Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 44/45] powerpc/32s: Allow mapping with BATs with DEBUG_PAGEALLOC Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-05-19 5:49 ` [PATCH v4 45/45] powerpc/32s: Implement dedicated kasan_init_region() Christophe Leroy 2020-05-19 5:49 ` Christophe Leroy 2020-06-09 5:28 ` [PATCH v4 00/45] Use hugepages to map kernel mem on 8xx Michael Ellerman
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