Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2 03/10] powerpc/6xx: Store PGDIR physical address in a SPRG | From | Christophe Leroy <> | Date | Thu, 7 Mar 2019 18:14:09 +0000 |
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Hi,
On 03/07/2019 02:11 PM, Guenter Roeck wrote: > Hi, > > On Thu, Feb 21, 2019 at 10:37:55AM +0000, Christophe Leroy wrote: >> Use SPRN_SPRG2 to store the current thread PGDIR and >> avoid reading thread_struct.pgdir at every TLB miss. >> > This patch causes a number of silent (no crash) qemu boot stalls > in -next. See > https://kerneltests.org/builders/qemu-ppc-next/builds/1080/steps/qemubuildcommand/logs/stdio > for an example.
Oops. Could you try the fix below ?
diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S index 6f1c11e0691f..7534ecff5e92 100644 --- a/arch/powerpc/kernel/cpu_setup_6xx.S +++ b/arch/powerpc/kernel/cpu_setup_6xx.S @@ -24,9 +24,6 @@ BEGIN_MMU_FTR_SECTION li r10,0 mtspr SPRN_SPRG_603_LRU,r10 /* init SW LRU tracking */ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU) - lis r10, (swapper_pg_dir - PAGE_OFFSET)@h - ori r10, r10, (swapper_pg_dir - PAGE_OFFSET)@l - mtspr SPRN_SPRG_PGDIR, r10
BEGIN_FTR_SECTION bl __init_fpu_registers diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index ce6a972f2584..48051c8977c5 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -855,6 +855,9 @@ __secondary_start: li r3,0 stw r3, RTAS_SP(r4) /* 0 => not in RTAS */ #endif + lis r4, (swapper_pg_dir - PAGE_OFFSET)@h + ori r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l + mtspr SPRN_SPRG_PGDIR, r4
/* enable MMU and jump to start_secondary */ li r4,MSR_KERNEL @@ -942,6 +945,9 @@ start_here: li r3,0 stw r3, RTAS_SP(r4) /* 0 => not in RTAS */ #endif + lis r4, (swapper_pg_dir - PAGE_OFFSET)@h + ori r4, r4, (swapper_pg_dir - PAGE_OFFSET)@l + mtspr SPRN_SPRG_PGDIR, r4
/* stack */ lis r1,init_thread_union@ha diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S index 1f13494efb2b..587e4550d83e 100644 --- a/arch/powerpc/mm/hash_low_32.S +++ b/arch/powerpc/mm/hash_low_32.S @@ -70,12 +70,12 @@ _GLOBAL(hash_page) lis r0,KERNELBASE@h /* check if kernel address */ cmplw 0,r4,r0 ori r3,r3,_PAGE_USER|_PAGE_PRESENT /* test low addresses as user */ - mfspr r5, SPRN_SPRG_PGDIR /* virt page-table root */ + mfspr r5, SPRN_SPRG_PGDIR /* phys page-table root */ blt+ 112f /* assume user more likely */ - lis r5,swapper_pg_dir@ha /* if kernel address, use */ - addi r5,r5,swapper_pg_dir@l /* kernel page table */ + 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 */ -112: tophys(r5, r5) +112: #ifndef CONFIG_PTE_64BIT rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */ lwz r8,0(r5) /* get pmd entry */
Thanks Christophe
> > Unfortunately, it is not possible to revert the patch due to subsequent > patches, so I was unable to test a revert. > > Bisect log is attached. > > Guenter > > --- > # bad: [cf08baa29613dd899954089e7cc7dba1d478b365] Add linux-next specific files for 20190306 > # good: [1c163f4c7b3f621efff9b28a47abb36f7378d783] Linux 5.0 > git bisect start 'HEAD' 'v5.0' > # bad: [6cc8f3499ec8d31904ab9083980a91736512cb37] Merge remote-tracking branch 'vfs/for-next' > git bisect bad 6cc8f3499ec8d31904ab9083980a91736512cb37 > # good: [63bdf4284c38a48af21745ceb148a087b190cd21] Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 > git bisect good 63bdf4284c38a48af21745ceb148a087b190cd21 > # good: [520b5fc601ab760fee7ea0c403b42d04e8ebfd93] Merge remote-tracking branch 'arm-soc/for-next' > git bisect good 520b5fc601ab760fee7ea0c403b42d04e8ebfd93 > # bad: [d7f54e4e0d4e90f5df78da8d6a830bafad3b535a] Merge remote-tracking branch 'xtensa/xtensa-for-next' > git bisect bad d7f54e4e0d4e90f5df78da8d6a830bafad3b535a > # good: [0c1a78523542fb3d2e6c5ac7955c8ca8f6482e6f] Merge remote-tracking branch 'clk/clk-next' > git bisect good 0c1a78523542fb3d2e6c5ac7955c8ca8f6482e6f > # bad: [fb0b0a73b223fc113e961b1d921322844e9c30d9] powerpc: Enable kcov > git bisect bad fb0b0a73b223fc113e961b1d921322844e9c30d9 > # good: [d0055df0c9c1471c389197a69f43e300185a75aa] Merge branch 'topic/dma' into next > git bisect good d0055df0c9c1471c389197a69f43e300185a75aa > # good: [0df977eafc792a5365a7f81d8d5920132e03afad] powerpc/6xx: Don't use SPRN_SPRG2 for storing stack pointer while in RTAS > git bisect good 0df977eafc792a5365a7f81d8d5920132e03afad > # bad: [665bed2386e5dc29844ad78c7ef1464664b103ec] powerpc/8xx: replace most #ifdef by IS_ENABLED() in 8xx_mmu.c > git bisect bad 665bed2386e5dc29844ad78c7ef1464664b103ec > # bad: [78ca1108b10927b3d068c8da91352b0f4cd01fc5] powerpc/book3s32: Reorder _PAGE_XXX flags to simplify TLB handling > git bisect bad 78ca1108b10927b3d068c8da91352b0f4cd01fc5 > # bad: [a8a121995b2e4f227fddc534c6bd5f1c02cbe2ee] powerpc/603: Don't handle kernel page TLB misses when not need > git bisect bad a8a121995b2e4f227fddc534c6bd5f1c02cbe2ee > # bad: [2c12393f577396a51b7e0537bd3eb29dcc26dc1b] powerpc/603: use physical address directly in TLB miss handlers. > git bisect bad 2c12393f577396a51b7e0537bd3eb29dcc26dc1b > # bad: [93c4a162b014d238a287f8264adb25c009c79e61] powerpc/6xx: Store PGDIR physical address in a SPRG > git bisect bad 93c4a162b014d238a287f8264adb25c009c79e61 > # first bad commit: [93c4a162b014d238a287f8264adb25c009c79e61] powerpc/6xx: Store PGDIR physical address in a SPRG >
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