Messages in this thread | | | Subject | Re: [PATCH v2 03/10] powerpc/6xx: Store PGDIR physical address in a SPRG | From | Christophe Leroy <> | Date | Thu, 7 Mar 2019 20:10:39 +0100 |
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Le 07/03/2019 à 20:07, Guenter Roeck a écrit : > On Thu, Mar 07, 2019 at 06:14:09PM +0000, Christophe Leroy wrote: >> 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 ? >> > > Yes, that does the trick. With this patch applied on top of next-20190306, > all my ppc qemu boot tests pass. > > Tested-by: Guenter Roeck <linux@roeck-us.net>
Thanks for testing.
I'll send a proper patch tomorrow morning, sorry for that.
Christophe
> > Guenter > >> 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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