sh: Revert TLB miss fast-path changes that broke PTEA parts.
authorPaul Mundt <lethal@linux-sh.org>
Wed, 14 Feb 2007 05:13:10 +0000 (14:13 +0900)
committerPaul Mundt <lethal@linux-sh.org>
Wed, 14 Feb 2007 05:13:10 +0000 (14:13 +0900)
This ended up causing problems for older parts (particularly ones
using PTEA). Revert this for now, it can be added back in once it's
had some more testing.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
arch/sh/kernel/cpu/sh3/entry.S
arch/sh/mm/fault.c
include/asm-sh/pgtable.h

index 1c520358ba90e8313915ae93d088a9883ec1d7d9..c19205b0f2c001d2ce1cd73c7dba7674890d102f 100644 (file)
 #include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
-#include <asm/unistd.h>
 #include <asm/cpu/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/page.h>
+#include <asm/unistd.h>
 
 ! NOTE:
 ! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address
@@ -138,14 +136,29 @@ ENTRY(tlb_protection_violation_store)
 
 call_dpf:
        mov.l   1f, r0
-       mov.l   @r0, r6         ! address
+       mov     r5, r8
+       mov.l   @r0, r6
+       mov     r6, r9
+       mov.l   2f, r0
+       sts     pr, r10
+       jsr     @r0
+        mov    r15, r4
+       !
+       tst     r0, r0
+       bf/s    0f
+        lds    r10, pr
+       rts
+        nop
+0:     sti
        mov.l   3f, r0
-
+       mov     r9, r6
+       mov     r8, r5
        jmp     @r0
-        mov    r15, r4         ! regs
+        mov    r15, r4
 
        .align 2
 1:     .long   MMU_TEA
+2:     .long   __do_page_fault
 3:     .long   do_page_fault
 
        .align  2
@@ -332,171 +345,9 @@ general_exception:
 !
 !
 
-/* gas doesn't flag impossible values for mov #immediate as an error */
-#if (_PAGE_PRESENT >> 2) > 0x7f
-#error cannot load PAGE_PRESENT as an immediate
-#endif
-#if _PAGE_DIRTY > 0x7f
-#error cannot load PAGE_DIRTY as an immediate
-#endif
-#if (_PAGE_PRESENT << 2) != _PAGE_ACCESSED
-#error cannot derive PAGE_ACCESSED from PAGE_PRESENT
-#endif
-
-#if defined(CONFIG_CPU_SH4)
-#define ldmmupteh(r)   mov.l   8f, r
-#else
-#define ldmmupteh(r)   mov     #MMU_PTEH, r
-#endif
-
        .balign         1024,0,1024
 tlb_miss:
-#ifdef COUNT_EXCEPTIONS
-       ! Increment the counts
-       mov.l   9f, k1
-       mov.l   @k1, k2
-       add     #1, k2
-       mov.l   k2, @k1
-#endif
-
-       ! k0 scratch
-       ! k1 pgd and pte pointers
-       ! k2 faulting address
-       ! k3 pgd and pte index masks
-       ! k4 shift
-
-       ! Load up the pgd entry (k1)
-
-       ldmmupteh(k0)                   !  9 LS (latency=2)     MMU_PTEH
-
-       mov.w   4f, k3                  !  8 LS (latency=2)     (PTRS_PER_PGD-1) << 2
-       mov     #-(PGDIR_SHIFT-2), k4   !  6 EX
-
-       mov.l   @(MMU_TEA-MMU_PTEH,k0), k2      ! 18 LS (latency=2)
-
-       mov.l   @(MMU_TTB-MMU_PTEH,k0), k1      ! 18 LS (latency=2)
-
-       mov     k2, k0                  !   5 MT (latency=0)
-       shld    k4, k0                  !  99 EX
-
-       and     k3, k0                  !  78 EX
-
-       mov.l   @(k0, k1), k1           !  21 LS (latency=2)
-       mov     #-(PAGE_SHIFT-2), k4    !   6 EX
-
-       ! Load up the pte entry (k2)
-
-       mov     k2, k0                  !   5 MT (latency=0)
-       shld    k4, k0                  !  99 EX
-
-       tst     k1, k1                  !  86 MT
-
-       bt      20f                     ! 110 BR
-
-       mov.w   3f, k3                  !  8 LS (latency=2)     (PTRS_PER_PTE-1) << 2
-       and     k3, k0                  !  78 EX
-       mov.w   5f, k4                  !   8 LS (latency=2)    _PAGE_PRESENT
-
-       mov.l   @(k0, k1), k2           !  21 LS (latency=2)
-       add     k0, k1                  !  49 EX
-
-#ifdef CONFIG_CPU_HAS_PTEA
-       ! Test the entry for present and _PAGE_ACCESSED
-
-       mov     #-28, k3                !   6 EX
-       mov     k2, k0                  !   5 MT (latency=0)
-
-       tst     k4, k2                  !  68 MT
-       shld    k3, k0                  !  99 EX
-
-       bt      20f                     ! 110 BR
-
-       ! Set PTEA register
-       ! MMU_PTEA = ((pteval >> 28) & 0xe) | (pteval & 0x1)
-       !
-       ! k0=pte>>28, k1=pte*, k2=pte, k3=<unused>, k4=_PAGE_PRESENT
-
-       and     #0xe, k0                !  79 EX
-
-       mov     k0, k3                  !   5 MT (latency=0)
-       mov     k2, k0                  !   5 MT (latency=0)
-
-       and     #1, k0                  !  79 EX
-
-       or      k0, k3                  !  82 EX
-
-       ldmmupteh(k0)                   !   9 LS (latency=2)
-       shll2   k4                      ! 101 EX                _PAGE_ACCESSED
-
-       tst     k4, k2                  !  68 MT
-
-       mov.l   k3, @(MMU_PTEA-MMU_PTEH,k0)     ! 27 LS
-
-       mov.l   7f, k3                  !   9 LS (latency=2)    _PAGE_FLAGS_HARDWARE_MASK
-
-       ! k0=MMU_PTEH, k1=pte*, k2=pte, k3=_PAGE_FLAGS_HARDWARE, k4=_PAGE_ACCESSED
-#else
-
-       ! Test the entry for present and _PAGE_ACCESSED
-
-       mov.l   7f, k3                  !   9 LS (latency=2)    _PAGE_FLAGS_HARDWARE_MASK
-       tst     k4, k2                  !  68 MT
-
-       shll2   k4                      ! 101 EX                _PAGE_ACCESSED
-       ldmmupteh(k0)                   !   9 LS (latency=2)
-
-       bt      20f                     ! 110 BR
-       tst     k4, k2                  !  68 MT
-
-       ! k0=MMU_PTEH, k1=pte*, k2=pte, k3=_PAGE_FLAGS_HARDWARE, k4=_PAGE_ACCESSED
-
-#endif
-
-       ! Set up the entry
-
-       and     k2, k3                  !  78 EX
-       bt/s    10f                     ! 108 BR
-
-        mov.l  k3, @(MMU_PTEL-MMU_PTEH,k0)     ! 27 LS
-
-       ldtlb                           ! 128 CO
-
-       ! At least one instruction between ldtlb and rte
-       nop                             ! 119 NOP
-
-       rte                             ! 126 CO
-
-        nop                            ! 119 NOP
-
-
-10:    or      k4, k2                  !  82 EX
-
-       ldtlb                           ! 128 CO
-
-       ! At least one instruction between ldtlb and rte
-       mov.l   k2, @k1                 !  27 LS
-
-       rte                             ! 126 CO
-
-       ! Note we cannot execute mov here, because it is executed after
-       ! restoring SSR, so would be executed in user space.
-        nop                            ! 119 NOP
-
-
-       .align 5
-       ! Once cache line if possible...
-1:     .long   swapper_pg_dir
-3:     .short  (PTRS_PER_PTE-1) << 2
-4:     .short  (PTRS_PER_PGD-1) << 2
-5:     .long   _PAGE_PRESENT
-7:     .long   _PAGE_FLAGS_HARDWARE_MASK
-8:     .long   MMU_PTEH
-#ifdef COUNT_EXCEPTIONS
-9:     .long   exception_count_miss
-#endif
-
-       ! Either pgd or pte not present
-20:    mov.l   1f, k2
+       mov.l   1f, k2
        mov.l   4f, k3
        bra     handle_exception
         mov.l  @k2, k2
@@ -647,15 +498,6 @@ skip_save:
        bf      interrupt_exception
        shlr2   r8
        shlr    r8
-
-#ifdef COUNT_EXCEPTIONS
-       mov.l   5f, r9
-       add     r8, r9
-       mov.l   @r9, r10
-       add     #1, r10
-       mov.l   r10, @r9
-#endif
-
        mov.l   4f, r9
        add     r8, r9
        mov.l   @r9, r9
@@ -669,9 +511,6 @@ skip_save:
 2:     .long   0x000080f0      ! FD=1, IMASK=15
 3:     .long   0xcfffffff      ! RB=0, BL=0
 4:     .long   exception_handling_table
-#ifdef COUNT_EXCEPTIONS
-5:     .long   exception_count_table
-#endif
 
 interrupt_exception:
        mov.l   1f, r9
index 716ebf568af20d2e2e7e303161d11304886ff794..fa5d7f0b9f1877a5b8bccedc71d97ce84d660a22 100644 (file)
@@ -17,6 +17,7 @@
 #include <linux/kprobes.h>
 #include <asm/system.h>
 #include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
 #include <asm/kgdb.h>
 
 extern void die(const char *,struct pt_regs *,long);
@@ -224,3 +225,89 @@ do_sigbus:
        if (!user_mode(regs))
                goto no_context;
 }
+
+#ifdef CONFIG_SH_STORE_QUEUES
+/*
+ * This is a special case for the SH-4 store queues, as pages for this
+ * space still need to be faulted in before it's possible to flush the
+ * store queue cache for writeout to the remapped region.
+ */
+#define P3_ADDR_MAX            (P4SEG_STORE_QUE + 0x04000000)
+#else
+#define P3_ADDR_MAX            P4SEG
+#endif
+
+/*
+ * Called with interrupts disabled.
+ */
+asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
+                                        unsigned long writeaccess,
+                                        unsigned long address)
+{
+       pgd_t *pgd;
+       pud_t *pud;
+       pmd_t *pmd;
+       pte_t *pte;
+       pte_t entry;
+       struct mm_struct *mm = current->mm;
+       spinlock_t *ptl;
+       int ret = 1;
+
+#ifdef CONFIG_SH_KGDB
+       if (kgdb_nofault && kgdb_bus_err_hook)
+               kgdb_bus_err_hook();
+#endif
+
+       /*
+        * We don't take page faults for P1, P2, and parts of P4, these
+        * are always mapped, whether it be due to legacy behaviour in
+        * 29-bit mode, or due to PMB configuration in 32-bit mode.
+        */
+       if (address >= P3SEG && address < P3_ADDR_MAX) {
+               pgd = pgd_offset_k(address);
+               mm = NULL;
+       } else {
+               if (unlikely(address >= TASK_SIZE || !mm))
+                       return 1;
+
+               pgd = pgd_offset(mm, address);
+       }
+
+       pud = pud_offset(pgd, address);
+       if (pud_none_or_clear_bad(pud))
+               return 1;
+       pmd = pmd_offset(pud, address);
+       if (pmd_none_or_clear_bad(pmd))
+               return 1;
+
+       if (mm)
+               pte = pte_offset_map_lock(mm, pmd, address, &ptl);
+       else
+               pte = pte_offset_kernel(pmd, address);
+
+       entry = *pte;
+       if (unlikely(pte_none(entry) || pte_not_present(entry)))
+               goto unlock;
+       if (unlikely(writeaccess && !pte_write(entry)))
+               goto unlock;
+
+       if (writeaccess)
+               entry = pte_mkdirty(entry);
+       entry = pte_mkyoung(entry);
+
+#ifdef CONFIG_CPU_SH4
+       /*
+        * ITLB is not affected by "ldtlb" instruction.
+        * So, we need to flush the entry by ourselves.
+        */
+       local_flush_tlb_one(get_asid(), address & PAGE_MASK);
+#endif
+
+       set_pte(pte, entry);
+       update_mmu_cache(NULL, address, entry);
+       ret = 0;
+unlock:
+       if (mm)
+               pte_unmap_unlock(pte, ptl);
+       return ret;
+}
index 3721a4412cea2ba17ec1d8ed4ba170e7d6a1383d..9214c015fe14a52e7c318f8ac79c78fcdd659286 100644 (file)
@@ -43,7 +43,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 /* PGD bits */
 #define PGDIR_SHIFT    (PTE_SHIFT + PTE_BITS)
 #define PGDIR_BITS     (32 - PGDIR_SHIFT)
-#define PGDIR_SIZE     (1 << PGDIR_SHIFT)
+#define PGDIR_SIZE     (1UL << PGDIR_SHIFT)
 #define PGDIR_MASK     (~(PGDIR_SIZE-1))
 
 /* Entries per level */