diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arc/mm/tlb.c | 57 |
1 files changed, 33 insertions, 24 deletions
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c index 8ceefbf72fb0..4097764fea23 100644 --- a/arch/arc/mm/tlb.c +++ b/arch/arc/mm/tlb.c @@ -762,21 +762,23 @@ void read_decode_mmu_bcr(void) tmp = read_aux_reg(ARC_REG_MMU_BCR); mmu->ver = (tmp >> 24); - if (mmu->ver <= 2) { - mmu2 = (struct bcr_mmu_1_2 *)&tmp; - mmu->pg_sz_k = TO_KB(0x2000); - mmu->sets = 1 << mmu2->sets; - mmu->ways = 1 << mmu2->ways; - mmu->u_dtlb = mmu2->u_dtlb; - mmu->u_itlb = mmu2->u_itlb; - } else if (mmu->ver == 3) { - mmu3 = (struct bcr_mmu_3 *)&tmp; - mmu->pg_sz_k = 1 << (mmu3->pg_sz - 1); - mmu->sets = 1 << mmu3->sets; - mmu->ways = 1 << mmu3->ways; - mmu->u_dtlb = mmu3->u_dtlb; - mmu->u_itlb = mmu3->u_itlb; - mmu->sasid = mmu3->sasid; + if (is_isa_arcompact()) { + if (mmu->ver <= 2) { + mmu2 = (struct bcr_mmu_1_2 *)&tmp; + mmu->pg_sz_k = TO_KB(0x2000); + mmu->sets = 1 << mmu2->sets; + mmu->ways = 1 << mmu2->ways; + mmu->u_dtlb = mmu2->u_dtlb; + mmu->u_itlb = mmu2->u_itlb; + } else { + mmu3 = (struct bcr_mmu_3 *)&tmp; + mmu->pg_sz_k = 1 << (mmu3->pg_sz - 1); + mmu->sets = 1 << mmu3->sets; + mmu->ways = 1 << mmu3->ways; + mmu->u_dtlb = mmu3->u_dtlb; + mmu->u_itlb = mmu3->u_itlb; + mmu->sasid = mmu3->sasid; + } } else { mmu4 = (struct bcr_mmu_4 *)&tmp; mmu->pg_sz_k = 1 << (mmu4->sz0 - 1); @@ -818,8 +820,9 @@ int pae40_exist_but_not_enab(void) void arc_mmu_init(void) { - char str[256]; struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu; + char str[256]; + int compat = 0; pr_info("%s", arc_mmu_mumbojumbo(0, str, sizeof(str))); @@ -834,15 +837,21 @@ void arc_mmu_init(void) */ BUILD_BUG_ON(!IS_ALIGNED(STACK_TOP, PMD_SIZE)); - /* For efficiency sake, kernel is compile time built for a MMU ver - * This must match the hardware it is running on. - * Linux built for MMU V2, if run on MMU V1 will break down because V1 - * hardware doesn't understand cmds such as WriteNI, or IVUTLB - * On the other hand, Linux built for V1 if run on MMU V2 will do - * un-needed workarounds to prevent memcpy thrashing. - * Similarly MMU V3 has new features which won't work on older MMU + /* + * Ensure that MMU features assumed by kernel exist in hardware. + * For older ARC700 cpus, it has to be exact match, since the MMU + * revisions were not backwards compatible (MMUv3 TLB layout changed + * so even if kernel for v2 didn't use any new cmds of v3, it would + * still not work. + * For HS cpus, MMUv4 was baseline and v5 is backwards compatible + * (will run older software). */ - if (mmu->ver != CONFIG_ARC_MMU_VER) { + if (is_isa_arcompact() && mmu->ver == CONFIG_ARC_MMU_VER) + compat = 1; + else if (is_isa_arcv2() && mmu->ver >= CONFIG_ARC_MMU_VER) + compat = 1; + + if (!compat) { panic("MMU ver %d doesn't match kernel built for %d...\n", mmu->ver, CONFIG_ARC_MMU_VER); } |