diff options
Diffstat (limited to 'arch/arc/mm/tlb.c')
| -rw-r--r-- | arch/arc/mm/tlb.c | 268 |
1 files changed, 32 insertions, 236 deletions
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c index 9c7c68247289..5f71445f26bd 100644 --- a/arch/arc/mm/tlb.c +++ b/arch/arc/mm/tlb.c @@ -1,51 +1,9 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * TLB Management (flush/create/diagnostics) for ARC700 + * TLB Management (flush/create/diagnostics) for MMUv3 and MMUv4 * * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * - * vineetg: Aug 2011 - * -Reintroduce duplicate PD fixup - some customer chips still have the issue - * - * vineetg: May 2011 - * -No need to flush_cache_page( ) for each call to update_mmu_cache() - * some of the LMBench tests improved amazingly - * = page-fault thrice as fast (75 usec to 28 usec) - * = mmap twice as fast (9.6 msec to 4.6 msec), - * = fork (5.3 msec to 3.7 msec) - * - * vineetg: April 2011 : - * -MMU v3: PD{0,1} bits layout changed: They don't overlap anymore, - * helps avoid a shift when preparing PD0 from PTE - * - * vineetg: April 2011 : Preparing for MMU V3 - * -MMU v2/v3 BCRs decoded differently - * -Remove TLB_SIZE hardcoding as it's variable now: 256 or 512 - * -tlb_entry_erase( ) can be void - * -local_flush_tlb_range( ): - * = need not "ceil" @end - * = walks MMU only if range spans < 32 entries, as opposed to 256 - * - * Vineetg: Sept 10th 2008 - * -Changes related to MMU v2 (Rel 4.8) - * - * Vineetg: Aug 29th 2008 - * -In TLB Flush operations (Metal Fix MMU) there is a explicit command to - * flush Micro-TLBS. If TLB Index Reg is invalid prior to TLBIVUTLB cmd, - * it fails. Thus need to load it with ANY valid value before invoking - * TLBIVUTLB cmd - * - * Vineetg: Aug 21th 2008: - * -Reduced the duration of IRQ lockouts in TLB Flush routines - * -Multiple copies of TLB erase code separated into a "single" function - * -In TLB Flush routines, interrupt disabling moved UP to retrieve ASID - * in interrupt-safe region. - * - * Vineetg: April 23rd Bug #93131 - * Problem: tlb_flush_kernel_range() doesn't do anything if the range to - * flush is more than the size of TLB itself. - * - * Rahul Trivedi : Codito Technologies 2004 */ #include <linux/module.h> @@ -57,47 +15,6 @@ #include <asm/mmu_context.h> #include <asm/mmu.h> -/* Need for ARC MMU v2 - * - * ARC700 MMU-v1 had a Joint-TLB for Code and Data and is 2 way set-assoc. - * For a memcpy operation with 3 players (src/dst/code) such that all 3 pages - * map into same set, there would be contention for the 2 ways causing severe - * Thrashing. - * - * Although J-TLB is 2 way set assoc, ARC700 caches J-TLB into uTLBS which has - * much higher associativity. u-D-TLB is 8 ways, u-I-TLB is 4 ways. - * Given this, the thrashing problem should never happen because once the 3 - * J-TLB entries are created (even though 3rd will knock out one of the prev - * two), the u-D-TLB and u-I-TLB will have what is required to accomplish memcpy - * - * Yet we still see the Thrashing because a J-TLB Write cause flush of u-TLBs. - * This is a simple design for keeping them in sync. So what do we do? - * The solution which James came up was pretty neat. It utilised the assoc - * of uTLBs by not invalidating always but only when absolutely necessary. - * - * - Existing TLB commands work as before - * - New command (TLBWriteNI) for TLB write without clearing uTLBs - * - New command (TLBIVUTLB) to invalidate uTLBs. - * - * The uTLBs need only be invalidated when pages are being removed from the - * OS page table. If a 'victim' TLB entry is being overwritten in the main TLB - * as a result of a miss, the removed entry is still allowed to exist in the - * uTLBs as it is still valid and present in the OS page table. This allows the - * full associativity of the uTLBs to hide the limited associativity of the main - * TLB. - * - * During a miss handler, the new "TLBWriteNI" command is used to load - * entries without clearing the uTLBs. - * - * When the OS page table is updated, TLB entries that may be associated with a - * removed page are removed (flushed) from the TLB using TLBWrite. In this - * circumstance, the uTLBs must also be cleared. This is done by using the - * existing TLBWrite command. An explicit IVUTLB is also required for those - * corner cases when TLBWrite was not executed at all because the corresp - * J-TLB entry got evicted/replaced. - */ - - /* A copy of the ASID from the PID reg is kept in asid_cache */ DEFINE_PER_CPU(unsigned int, asid_cache) = MM_CTXT_FIRST_CYCLE; @@ -120,32 +37,10 @@ static inline void __tlb_entry_erase(void) static void utlb_invalidate(void) { -#if (CONFIG_ARC_MMU_VER >= 2) - -#if (CONFIG_ARC_MMU_VER == 2) - /* MMU v2 introduced the uTLB Flush command. - * There was however an obscure hardware bug, where uTLB flush would - * fail when a prior probe for J-TLB (both totally unrelated) would - * return lkup err - because the entry didn't exist in MMU. - * The Workaround was to set Index reg with some valid value, prior to - * flush. This was fixed in MMU v3 - */ - unsigned int idx; - - /* make sure INDEX Reg is valid */ - idx = read_aux_reg(ARC_REG_TLBINDEX); - - /* If not write some dummy val */ - if (unlikely(idx & TLB_LKUP_ERR)) - write_aux_reg(ARC_REG_TLBINDEX, 0xa); -#endif - write_aux_reg(ARC_REG_TLBCOMMAND, TLBIVUTLB); -#endif - } -#if (CONFIG_ARC_MMU_VER < 4) +#ifdef CONFIG_ARC_MMU_V3 static inline unsigned int tlb_entry_lkup(unsigned long vaddr_n_asid) { @@ -176,7 +71,7 @@ static void tlb_entry_erase(unsigned int vaddr_n_asid) } } -static void tlb_entry_insert(unsigned int pd0, pte_t pd1) +static void tlb_entry_insert(unsigned int pd0, phys_addr_t pd1) { unsigned int idx; @@ -206,7 +101,7 @@ static void tlb_entry_insert(unsigned int pd0, pte_t pd1) write_aux_reg(ARC_REG_TLBCOMMAND, TLBWrite); } -#else /* CONFIG_ARC_MMU_VER >= 4) */ +#else /* MMUv4 */ static void tlb_entry_erase(unsigned int vaddr_n_asid) { @@ -214,13 +109,16 @@ static void tlb_entry_erase(unsigned int vaddr_n_asid) write_aux_reg(ARC_REG_TLBCOMMAND, TLBDeleteEntry); } -static void tlb_entry_insert(unsigned int pd0, pte_t pd1) +static void tlb_entry_insert(unsigned int pd0, phys_addr_t pd1) { write_aux_reg(ARC_REG_TLBPD0, pd0); - write_aux_reg(ARC_REG_TLBPD1, pd1); - if (is_pae40_enabled()) + if (!is_pae40_enabled()) { + write_aux_reg(ARC_REG_TLBPD1, pd1); + } else { + write_aux_reg(ARC_REG_TLBPD1, pd1 & 0xFFFFFFFF); write_aux_reg(ARC_REG_TLBPD1HI, (u64)pd1 >> 32); + } write_aux_reg(ARC_REG_TLBCOMMAND, TLBInsertEntry); } @@ -496,7 +394,7 @@ void create_tlb(struct vm_area_struct *vma, unsigned long vaddr, pte_t *ptep) unsigned long flags; unsigned int asid_or_sasid, rwx; unsigned long pd0; - pte_t pd1; + phys_addr_t pd1; /* * create_tlb() assumes that current->mm == vma->mm, since @@ -505,7 +403,6 @@ void create_tlb(struct vm_area_struct *vma, unsigned long vaddr, pte_t *ptep) * * Removing the assumption involves * -Using vma->mm->context{ASID,SASID}, as opposed to MMU reg. - * -Fix the TLB paranoid debug code to not trigger false negatives. * -More importantly it makes this handler inconsistent with fast-path * TLB Refill handler which always deals with "current" * @@ -528,8 +425,6 @@ void create_tlb(struct vm_area_struct *vma, unsigned long vaddr, pte_t *ptep) local_irq_save(flags); - tlb_paranoid_check(asid_mm(vma->vm_mm, smp_processor_id()), vaddr); - vaddr &= PAGE_MASK; /* update this PTE credentials */ @@ -639,43 +534,6 @@ void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, update_mmu_cache(vma, addr, &pte); } -void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, - pgtable_t pgtable) -{ - struct list_head *lh = (struct list_head *) pgtable; - - assert_spin_locked(&mm->page_table_lock); - - /* FIFO */ - if (!pmd_huge_pte(mm, pmdp)) - INIT_LIST_HEAD(lh); - else - list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); - pmd_huge_pte(mm, pmdp) = pgtable; -} - -pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) -{ - struct list_head *lh; - pgtable_t pgtable; - - assert_spin_locked(&mm->page_table_lock); - - pgtable = pmd_huge_pte(mm, pmdp); - lh = (struct list_head *) pgtable; - if (list_empty(lh)) - pmd_huge_pte(mm, pmdp) = NULL; - else { - pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; - list_del(lh); - } - - pte_val(pgtable[0]) = 0; - pte_val(pgtable[1]) = 0; - - return pgtable; -} - void local_flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { @@ -706,14 +564,6 @@ void read_decode_mmu_bcr(void) { struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu; unsigned int tmp; - struct bcr_mmu_1_2 { -#ifdef CONFIG_CPU_BIG_ENDIAN - unsigned int ver:8, ways:4, sets:4, u_itlb:8, u_dtlb:8; -#else - unsigned int u_dtlb:8, u_itlb:8, sets:4, ways:4, ver:8; -#endif - } *mmu2; - struct bcr_mmu_3 { #ifdef CONFIG_CPU_BIG_ENDIAN unsigned int ver:8, ways:4, sets:4, res:3, sasid:1, pg_sz:4, @@ -738,23 +588,14 @@ void read_decode_mmu_bcr(void) tmp = read_aux_reg(ARC_REG_MMU_BCR); mmu->ver = (tmp >> 24); - 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; - } + if (is_isa_arcompact() && 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; } else { mmu4 = (struct bcr_mmu_4 *)&tmp; mmu->pg_sz_k = 1 << (mmu4->sz0 - 1); @@ -780,8 +621,8 @@ char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len) IS_USED_CFG(CONFIG_TRANSPARENT_HUGEPAGE)); n += scnprintf(buf + n, len - n, - "MMU [v%x]\t: %dk PAGE, %sJTLB %d (%dx%d), uDTLB %d, uITLB %d%s%s\n", - p_mmu->ver, p_mmu->pg_sz_k, super_pg, + "MMU [v%x]\t: %dk PAGE, %s, swalk %d lvl, JTLB %d (%dx%d), uDTLB %d, uITLB %d%s%s\n", + p_mmu->ver, p_mmu->pg_sz_k, super_pg, CONFIG_PGTABLE_LEVELS, p_mmu->sets * p_mmu->ways, p_mmu->sets, p_mmu->ways, p_mmu->u_dtlb, p_mmu->u_itlb, IS_AVAIL2(p_mmu->pae, ", PAE40 ", CONFIG_ARC_HAS_PAE40)); @@ -815,22 +656,17 @@ void arc_mmu_init(void) /* * 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). + * - For older ARC700 cpus, only v3 supported + * - For HS cpus, v4 was baseline and v5 is backwards compatible + * (will run older software). */ - if (is_isa_arcompact() && mmu->ver == CONFIG_ARC_MMU_VER) + if (is_isa_arcompact() && mmu->ver == 3) compat = 1; - else if (is_isa_arcv2() && mmu->ver >= CONFIG_ARC_MMU_VER) + else if (is_isa_arcv2() && mmu->ver >= 4) compat = 1; - if (!compat) { - panic("MMU ver %d doesn't match kernel built for %d...\n", - mmu->ver, CONFIG_ARC_MMU_VER); - } + if (!compat) + panic("MMU ver %d doesn't match kernel built for\n", mmu->ver); if (mmu->pg_sz_k != TO_KB(PAGE_SIZE)) panic("MMU pg size != PAGE_SIZE (%luk)\n", TO_KB(PAGE_SIZE)); @@ -843,14 +679,11 @@ void arc_mmu_init(void) if (IS_ENABLED(CONFIG_ARC_HAS_PAE40) && !mmu->pae) panic("Hardware doesn't support PAE40\n"); - /* Enable the MMU */ - write_aux_reg(ARC_REG_PID, MMU_ENABLE); + /* Enable the MMU with ASID 0 */ + mmu_setup_asid(NULL, 0); - /* In smp we use this reg for interrupt 1 scratch */ -#ifdef ARC_USE_SCRATCH_REG - /* swapper_pg_dir is the pgd for the kernel, used by vmalloc */ - write_aux_reg(ARC_REG_SCRATCH_DATA0, swapper_pg_dir); -#endif + /* cache the pgd pointer in MMU SCRATCH reg (ARCv2 only) */ + mmu_setup_pgd(NULL, swapper_pg_dir); if (pae40_exist_but_not_enab()) write_aux_reg(ARC_REG_TLBPD1HI, 0); @@ -945,40 +778,3 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address, local_irq_restore(flags); } - -/*********************************************************************** - * Diagnostic Routines - * -Called from Low Level TLB Handlers if things don;t look good - **********************************************************************/ - -#ifdef CONFIG_ARC_DBG_TLB_PARANOIA - -/* - * Low Level ASM TLB handler calls this if it finds that HW and SW ASIDS - * don't match - */ -void print_asid_mismatch(int mm_asid, int mmu_asid, int is_fast_path) -{ - pr_emerg("ASID Mismatch in %s Path Handler: sw-pid=0x%x hw-pid=0x%x\n", - is_fast_path ? "Fast" : "Slow", mm_asid, mmu_asid); - - __asm__ __volatile__("flag 1"); -} - -void tlb_paranoid_check(unsigned int mm_asid, unsigned long addr) -{ - unsigned int mmu_asid; - - mmu_asid = read_aux_reg(ARC_REG_PID) & 0xff; - - /* - * At the time of a TLB miss/installation - * - HW version needs to match SW version - * - SW needs to have a valid ASID - */ - if (addr < 0x70000000 && - ((mm_asid == MM_CTXT_NO_ASID) || - (mmu_asid != (mm_asid & MM_CTXT_ASID_MASK)))) - print_asid_mismatch(mm_asid, mmu_asid, 0); -} -#endif |