diff options
Diffstat (limited to 'arch/arc/mm/tlbex.S')
| -rw-r--r-- | arch/arc/mm/tlbex.S | 128 |
1 files changed, 55 insertions, 73 deletions
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S index b30e4e36bb00..dc65e87a531f 100644 --- a/arch/arc/mm/tlbex.S +++ b/arch/arc/mm/tlbex.S @@ -1,26 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * TLB Exception Handling for ARC * * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * * Vineetg: April 2011 : - * -MMU v1: moved out legacy code into a seperate file + * -MMU v1: moved out legacy code into a separate file * -MMU v3: PD{0,1} bits layout changed: They don't overlap anymore, * helps avoid a shift when preparing PD0 from PTE * * Vineetg: July 2009 - * -For MMU V2, we need not do heuristics at the time of commiting a D-TLB - * entry, so that it doesn't knock out it's I-TLB entry + * -For MMU V2, we need not do heuristics at the time of committing a D-TLB + * entry, so that it doesn't knock out its I-TLB entry * -Some more fine tuning: * bmsk instead of add, asl.cc instead of branch, delay slot utilise etc * * Vineetg: July 2009 * -Practically rewrote the I/D TLB Miss handlers - * Now 40 and 135 instructions a peice as compared to 131 and 449 resp. + * Now 40 and 135 instructions apiece as compared to 131 and 449 resp. * Hence Leaner by 1.5 K * Used Conditional arithmetic to replace excessive branching * Also used short instructions wherever possible @@ -36,13 +33,12 @@ */ #include <linux/linkage.h> +#include <linux/pgtable.h> #include <asm/entry.h> #include <asm/mmu.h> -#include <asm/pgtable.h> #include <asm/arcregs.h> #include <asm/cache.h> #include <asm/processor.h> -#include <asm/tlb-mmu1.h> #ifdef CONFIG_ISA_ARCOMPACT ;----------------------------------------------------------------- @@ -97,11 +93,6 @@ ex_saved_reg1: st_s r1, [r0, 4] st_s r2, [r0, 8] st_s r3, [r0, 12] - - ; VERIFY if the ASID in MMU-PID Reg is same as - ; one in Linux data structures - - tlb_paranoid_check_asm .endm .macro TLBMISS_RESTORE_REGS @@ -125,69 +116,42 @@ ex_saved_reg1: #else /* ARCv2 */ .macro TLBMISS_FREEUP_REGS +#ifdef CONFIG_ARC_HAS_LL64 + std r0, [sp, -16] + std r2, [sp, -8] +#else PUSH r0 PUSH r1 PUSH r2 PUSH r3 +#endif .endm .macro TLBMISS_RESTORE_REGS +#ifdef CONFIG_ARC_HAS_LL64 + ldd r0, [sp, -16] + ldd r2, [sp, -8] +#else POP r3 POP r2 POP r1 POP r0 +#endif .endm #endif ;============================================================================ -; Troubleshooting Stuff +;TLB Miss handling Code ;============================================================================ -; Linux keeps ASID (Address Space ID) in task->active_mm->context.asid -; When Creating TLB Entries, instead of doing 3 dependent loads from memory, -; we use the MMU PID Reg to get current ASID. -; In bizzare scenrios SW and HW ASID can get out-of-sync which is trouble. -; So we try to detect this in TLB Mis shandler - -.macro tlb_paranoid_check_asm - -#ifdef CONFIG_ARC_DBG_TLB_PARANOIA - - GET_CURR_TASK_ON_CPU r3 - ld r0, [r3, TASK_ACT_MM] - ld r0, [r0, MM_CTXT+MM_CTXT_ASID] - breq r0, 0, 55f ; Error if no ASID allocated - - lr r1, [ARC_REG_PID] - and r1, r1, 0xFF - - and r2, r0, 0xFF ; MMU PID bits only for comparison - breq r1, r2, 5f - -55: - ; Error if H/w and S/w ASID don't match, but NOT if in kernel mode - lr r2, [erstatus] - bbit0 r2, STATUS_U_BIT, 5f - - ; We sure are in troubled waters, Flag the error, but to do so - ; need to switch to kernel mode stack to call error routine - GET_TSK_STACK_BASE r3, sp - - ; Call printk to shoutout aloud - mov r2, 1 - j print_asid_mismatch - -5: ; ASIDs match so proceed normally - nop - +#ifndef PMD_SHIFT +#define PMD_SHIFT PUD_SHIFT #endif -.endm - -;============================================================================ -;TLB Miss handling Code -;============================================================================ +#ifndef PUD_SHIFT +#define PUD_SHIFT PGDIR_SHIFT +#endif ;----------------------------------------------------------------------------- ; This macro does the page-table lookup for the faulting address. @@ -196,7 +160,7 @@ ex_saved_reg1: lr r2, [efa] -#ifndef CONFIG_SMP +#ifdef CONFIG_ISA_ARCV2 lr r1, [ARC_REG_SCRATCH_DATA0] ; current pgd #else GET_CURR_TASK_ON_CPU r1 @@ -209,6 +173,24 @@ ex_saved_reg1: tst r3, r3 bz do_slow_path_pf ; if no Page Table, do page fault +#if CONFIG_PGTABLE_LEVELS > 3 + lsr r0, r2, PUD_SHIFT ; Bits for indexing into PUD + and r0, r0, (PTRS_PER_PUD - 1) + ld.as r1, [r3, r0] ; PMD entry + tst r1, r1 + bz do_slow_path_pf + mov r3, r1 +#endif + +#if CONFIG_PGTABLE_LEVELS > 2 + lsr r0, r2, PMD_SHIFT ; Bits for indexing into PMD + and r0, r0, (PTRS_PER_PMD - 1) + ld.as r1, [r3, r0] ; PMD entry + tst r1, r1 + bz do_slow_path_pf + mov r3, r1 +#endif + #ifdef CONFIG_TRANSPARENT_HUGEPAGE and.f 0, r3, _PAGE_HW_SZ ; Is this Huge PMD (thp) add2.nz r1, r1, r0 @@ -272,21 +254,19 @@ ex_saved_reg1: ; Commit the TLB entry into MMU .macro COMMIT_ENTRY_TO_MMU -#if (CONFIG_ARC_MMU_VER < 4) +#ifdef CONFIG_ARC_MMU_V3 /* Get free TLB slot: Set = computed from vaddr, way = random */ sr TLBGetIndex, [ARC_REG_TLBCOMMAND] /* Commit the Write */ -#if (CONFIG_ARC_MMU_VER >= 2) /* introduced in v2 */ sr TLBWriteNI, [ARC_REG_TLBCOMMAND] -#else - sr TLBWrite, [ARC_REG_TLBCOMMAND] -#endif #else sr TLBInsertEntry, [ARC_REG_TLBCOMMAND] #endif + +88: .endm @@ -364,21 +344,12 @@ ENTRY(EV_TLBMissD) ;---------------------------------------------------------------- ; UPDATE_PTE: Let Linux VM know that page was accessed/dirty - lr r3, [ecr] or r0, r0, _PAGE_ACCESSED ; Accessed bit always - btst_s r3, ECR_C_BIT_DTLB_ST_MISS ; See if it was a Write Access ? or.nz r0, r0, _PAGE_DIRTY ; if Write, set Dirty bit as well st_s r0, [r1] ; Write back PTE CONV_PTE_TO_TLB -#if (CONFIG_ARC_MMU_VER == 1) - ; MMU with 2 way set assoc J-TLB, needs some help in pathetic case of - ; memcpy where 3 parties contend for 2 ways, ensuing a livelock. - ; But only for old MMU or one with Metal Fix - TLB_WRITE_HEURISTICS -#endif - COMMIT_ENTRY_TO_MMU TLBMISS_RESTORE_REGS EV_TLBMissD_fast_ret: ; additional label for VDK OS-kit instrumentation @@ -387,6 +358,17 @@ EV_TLBMissD_fast_ret: ; additional label for VDK OS-kit instrumentation ;-------- Common routine to call Linux Page Fault Handler ----------- do_slow_path_pf: +#ifdef CONFIG_ISA_ARCV2 + ; Set Z flag if exception in U mode. Hardware micro-ops do this on any + ; taken interrupt/exception, and thus is already the case at the entry + ; above, but ensuing code would have already clobbered. + ; EXCEPTION_PROLOGUE called in slow path, relies on correct Z flag set + + lr r2, [erstatus] + and r2, r2, STATUS_U_MASK + bxor.f 0, r2, STATUS_U_BIT +#endif + ; Restore the 4-scratch regs saved by fast path miss handler TLBMISS_RESTORE_REGS |