From 33eee330cc8a445ff05f39a58af3c87324798230 Mon Sep 17 00:00:00 2001 From: Scott Wood Date: Tue, 14 Aug 2012 10:14:53 +0000 Subject: powerpc/fsl-corenet: work around erratum A004510 Erratum A004510 says that under certain load conditions, modified cache lines can be discarded, causing data corruption. To work around this, several CCSR and DCSR register updates need to be made in a careful manner, so that there is no other transaction in corenet when the update is made. The update is made from a locked cacheline, with a delay before to flush any previous activity, and a delay after to flush the CCSR/DCSR update. We can't use a readback because that would be another corenet transaction, which is not allowed. We lock the subsequent cacheline to prevent it from being fetched while we're executing the previous cacheline. It is filled with nops so that a branch doesn't cause us to fetch another cacheline. Ordinarily we are running in a cache-inhibited mapping at this point, so we temporarily change that. We make it guarded so that we should never see a speculative load, and we never do an explicit load. Thus, only the I-cache should ever fill from this mapping, and we flush/unlock it afterward. Thus we should avoid problems from any potential cache aliasing between inhibited and non-inhibited mappings. NOTE that if PAMU is used with this patch, it will need to use a dedicated LAW as described in the erratum. This is the responsibility of the OS that sets up PAMU. Signed-off-by: Scott Wood Signed-off-by: Andy Fleming --- arch/powerpc/cpu/mpc85xx/cmd_errata.c | 3 + arch/powerpc/cpu/mpc85xx/release.S | 27 ++++ arch/powerpc/cpu/mpc85xx/start.S | 284 ++++++++++++++++++++++++++++++++++ 3 files changed, 314 insertions(+) (limited to 'arch/powerpc/cpu/mpc85xx') diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c b/arch/powerpc/cpu/mpc85xx/cmd_errata.c index 858b3f8..e8989bd 100644 --- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c +++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c @@ -124,6 +124,9 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) if ((SVR_MAJ(svr) == 1) || IS_SVR_REV(svr, 2, 0)) puts("Work-around for Erratum NMG ETSEC129 enabled\n"); #endif +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510 + puts("Work-around for Erratum A004510 enabled\n"); +#endif return 0; } diff --git a/arch/powerpc/cpu/mpc85xx/release.S b/arch/powerpc/cpu/mpc85xx/release.S index 1555a9b..043d0ff 100644 --- a/arch/powerpc/cpu/mpc85xx/release.S +++ b/arch/powerpc/cpu/mpc85xx/release.S @@ -74,6 +74,33 @@ __secondary_start_page: mtspr 977,r3 #endif +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510 + mfspr r3,SPRN_SVR + rlwinm r3,r3,0,0xff + li r4,CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV + cmpw r3,r4 + beq 1f + +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 + li r4,CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 + cmpw r3,r4 + beq 1f +#endif + + /* Not a supported revision affected by erratum */ + b 2f + +1: /* Erratum says set bits 55:60 to 001001 */ + msync + isync + mfspr r3,976 + li r4,0x48 + rlwimi r3,r4,0,0x1f8 + mtspr 976,r3 + isync +2: +#endif + /* Enable branch prediction */ lis r3,BUCSR_ENABLE@h ori r3,r3,BUCSR_ENABLE@l diff --git a/arch/powerpc/cpu/mpc85xx/start.S b/arch/powerpc/cpu/mpc85xx/start.S index b1998b2..66e8eb8 100644 --- a/arch/powerpc/cpu/mpc85xx/start.S +++ b/arch/powerpc/cpu/mpc85xx/start.S @@ -86,6 +86,35 @@ _start_e500: li r1,MSR_DE mtmsr r1 +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510 + mfspr r3,SPRN_SVR + rlwinm r3,r3,0,0xff + li r4,CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV + cmpw r3,r4 + beq 1f + +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 + li r4,CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 + cmpw r3,r4 + beq 1f +#endif + + /* Not a supported revision affected by erratum */ + li r27,0 + b 2f + +1: li r27,1 /* Remember for later that we have the erratum */ + /* Erratum says set bits 55:60 to 001001 */ + msync + isync + mfspr r3,976 + li r4,0x48 + rlwimi r3,r4,0,0x1f8 + mtspr 976,r3 + isync +2: +#endif + #if defined(CONFIG_SECURE_BOOT) && defined(CONFIG_E500MC) /* ISBC uses L2 as stack. * Disable L2 cache here so that u-boot can enable it later @@ -440,6 +469,14 @@ nexti: mflr r1 /* R1 = our PC */ mfspr r2, MAS2 andc r2, r2, r3 or r2, r2, r1 +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510 + cmpwi r27,0 + beq 1f + andi. r15, r2, MAS2_I|MAS2_G /* save the old I/G for later */ + rlwinm r2, r2, 0, ~MAS2_I + ori r2, r2, MAS2_G +1: +#endif mtspr MAS2, r2 /* Set the EPN to our PC base address */ mfspr r2, MAS3 @@ -719,6 +756,253 @@ delete_temp_tlbs: tlbwe #endif /* #if (CONFIG_SYS_CCSRBAR_DEFAULT != CONFIG_SYS_CCSRBAR_PHYS) */ +#ifdef CONFIG_SYS_FSL_ERRATUM_A004510 +#define DCSR_LAWBARH0 (CONFIG_SYS_CCSRBAR + 0x1000) +#define LAW_SIZE_1M 0x13 +#define DCSRBAR_LAWAR (LAW_EN | (0x1d << 20) | LAW_SIZE_1M) + + cmpwi r27,0 + beq 9f + + /* + * Create a TLB entry for CCSR + * + * We're executing out of TLB1 entry in r14, and that's the only + * TLB entry that exists. To allocate some TLB entries for our + * own use, flip a bit high enough that we won't flip it again + * via incrementing. + */ + + xori r8, r14, 32 + lis r0, MAS0_TLBSEL(1)@h + rlwimi r0, r8, 16, MAS0_ESEL_MSK + lis r1, FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_16M)@h + ori r1, r1, FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_16M)@l + lis r7, CONFIG_SYS_CCSRBAR@h + ori r7, r7, CONFIG_SYS_CCSRBAR@l + ori r2, r7, MAS2_I|MAS2_G + lis r3, FSL_BOOKE_MAS3(CONFIG_SYS_CCSRBAR_PHYS_LOW, 0, (MAS3_SW|MAS3_SR))@h + ori r3, r3, FSL_BOOKE_MAS3(CONFIG_SYS_CCSRBAR_PHYS_LOW, 0, (MAS3_SW|MAS3_SR))@l + lis r4, CONFIG_SYS_CCSRBAR_PHYS_HIGH@h + ori r4, r4, CONFIG_SYS_CCSRBAR_PHYS_HIGH@l + mtspr MAS0, r0 + mtspr MAS1, r1 + mtspr MAS2, r2 + mtspr MAS3, r3 + mtspr MAS7, r4 + isync + tlbwe + isync + msync + + /* Map DCSR temporarily to physical address zero */ + li r0, 0 + lis r3, DCSRBAR_LAWAR@h + ori r3, r3, DCSRBAR_LAWAR@l + + stw r0, 0xc00(r7) /* LAWBARH0 */ + stw r0, 0xc04(r7) /* LAWBARL0 */ + sync + stw r3, 0xc08(r7) /* LAWAR0 */ + + /* Read back from LAWAR to ensure the update is complete. */ + lwz r3, 0xc08(r7) /* LAWAR0 */ + isync + + /* Create a TLB entry for DCSR at zero */ + + addi r9, r8, 1 + lis r0, MAS0_TLBSEL(1)@h + rlwimi r0, r9, 16, MAS0_ESEL_MSK + lis r1, FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_1M)@h + ori r1, r1, FSL_BOOKE_MAS1(1, 1, 0, 0, BOOKE_PAGESZ_1M)@l + li r6, 0 /* DCSR effective address */ + ori r2, r6, MAS2_I|MAS2_G + li r3, MAS3_SW|MAS3_SR + li r4, 0 + mtspr MAS0, r0 + mtspr MAS1, r1 + mtspr MAS2, r2 + mtspr MAS3, r3 + mtspr MAS7, r4 + isync + tlbwe + isync + msync + + /* enable the timebase */ +#define CTBENR 0xe2084 + li r3, 1 + addis r4, r7, CTBENR@ha + stw r3, CTBENR@l(r4) + lwz r3, CTBENR@l(r4) + twi 0,r3,0 + isync + + .macro erratum_set_ccsr offset value + addis r3, r7, \offset@ha + lis r4, \value@h + addi r3, r3, \offset@l + ori r4, r4, \value@l + bl erratum_set_value + .endm + + .macro erratum_set_dcsr offset value + addis r3, r6, \offset@ha + lis r4, \value@h + addi r3, r3, \offset@l + ori r4, r4, \value@l + bl erratum_set_value + .endm + + erratum_set_dcsr 0xb0e08 0xe0201800 + erratum_set_dcsr 0xb0e18 0xe0201800 + erratum_set_dcsr 0xb0e38 0xe0400000 + erratum_set_dcsr 0xb0008 0x00900000 + erratum_set_dcsr 0xb0e40 0xe00a0000 + erratum_set_ccsr 0x18600 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY + erratum_set_ccsr 0x10f00 0x415e5000 + erratum_set_ccsr 0x11f00 0x415e5000 + + /* Make temp mapping uncacheable again, if it was initially */ + bl 2f +2: mflr r3 + tlbsx 0, r3 + mfspr r4, MAS2 + rlwimi r4, r15, 0, MAS2_I + rlwimi r4, r15, 0, MAS2_G + mtspr MAS2, r4 + isync + tlbwe + isync + msync + + /* Clear the cache */ + lis r3,(L1CSR1_ICFI|L1CSR1_ICLFR)@h + ori r3,r3,(L1CSR1_ICFI|L1CSR1_ICLFR)@l + sync + isync + mtspr SPRN_L1CSR1,r3 + isync +2: sync + mfspr r4,SPRN_L1CSR1 + and. r4,r4,r3 + bne 2b + + lis r3,(L1CSR1_CPE|L1CSR1_ICE)@h + ori r3,r3,(L1CSR1_CPE|L1CSR1_ICE)@l + sync + isync + mtspr SPRN_L1CSR1,r3 + isync +2: sync + mfspr r4,SPRN_L1CSR1 + and. r4,r4,r3 + beq 2b + + /* Remove temporary mappings */ + lis r0, MAS0_TLBSEL(1)@h + rlwimi r0, r9, 16, MAS0_ESEL_MSK + li r3, 0 + mtspr MAS0, r0 + mtspr MAS1, r3 + isync + tlbwe + isync + msync + + li r3, 0 + stw r3, 0xc08(r7) /* LAWAR0 */ + lwz r3, 0xc08(r7) + isync + + lis r0, MAS0_TLBSEL(1)@h + rlwimi r0, r8, 16, MAS0_ESEL_MSK + li r3, 0 + mtspr MAS0, r0 + mtspr MAS1, r3 + isync + tlbwe + isync + msync + + b 9f + + /* r3 = addr, r4 = value, clobbers r5, r11, r12 */ +erratum_set_value: + /* Lock two cache lines into I-Cache */ + sync + mfspr r11, SPRN_L1CSR1 + rlwinm r11, r11, 0, ~L1CSR1_ICUL + sync + isync + mtspr SPRN_L1CSR1, r11 + isync + + mflr r12 + bl 5f +5: mflr r5 + addi r5, r5, 2f - 5b + icbtls 0, 0, r5 + addi r5, r5, 64 + + sync + mfspr r11, SPRN_L1CSR1 +3: andi. r11, r11, L1CSR1_ICUL + bne 3b + + icbtls 0, 0, r5 + addi r5, r5, 64 + + sync + mfspr r11, SPRN_L1CSR1 +3: andi. r11, r11, L1CSR1_ICUL + bne 3b + + b 2f + .align 6 + /* Inside a locked cacheline, wait a while, write, then wait a while */ +2: sync + + mfspr r5, SPRN_TBRL + addis r11, r5, 0x10000@h /* wait 65536 timebase ticks */ +4: mfspr r5, SPRN_TBRL + subf. r5, r5, r11 + bgt 4b + + stw r4, 0(r3) + + mfspr r5, SPRN_TBRL + addis r11, r5, 0x10000@h /* wait 65536 timebase ticks */ +4: mfspr r5, SPRN_TBRL + subf. r5, r5, r11 + bgt 4b + + sync + + /* + * Fill out the rest of this cache line and the next with nops, + * to ensure that nothing outside the locked area will be + * fetched due to a branch. + */ + .rept 19 + nop + .endr + + sync + mfspr r11, SPRN_L1CSR1 + rlwinm r11, r11, 0, ~L1CSR1_ICUL + sync + isync + mtspr SPRN_L1CSR1, r11 + isync + + mtlr r12 + blr + +9: +#endif + create_init_ram_area: lis r6,FSL_BOOKE_MAS0(1, 15, 0)@h ori r6,r6,FSL_BOOKE_MAS0(1, 15, 0)@l -- cgit v1.1