[SPARC64]: Document the instruction checks we do in do_sparc64_fault().

[safe/jmp/linux-2.6] / arch / sparc64 / mm / fault.c

diff --git a/arch/sparc64/mm/fault.c b/arch/sparc64/mm/fault.c
index 31fbc67..6e002aa 100644 (file)
--- a/arch/sparc64/mm/fault.c
+++ b/arch/sparc64/mm/fault.c
@@ -29,8 +29,7 @@
 #include <asm/lsu.h>
 #include <asm/sections.h>
 #include <asm/kdebug.h>
-
-#define ELEMENTS(arr) (sizeof (arr)/sizeof (arr[0]))
+#include <asm/mmu_context.h>
 
 /*
  * To debug kernel to catch accesses to certain virtual/physical addresses.
@@ -93,12 +92,13 @@ static void __kprobes unhandled_fault(unsigned long address,
        die_if_kernel("Oops", regs);
 }
 
-static void bad_kernel_pc(struct pt_regs *regs)
+static void bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
 {
        unsigned long *ksp;
 
        printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
               regs->tpc);
+       printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
        __asm__("mov %%sp, %0" : "=r" (ksp));
        show_stack(current, ksp);
        unhandled_fault(regs->tpc, current, regs);
@@ -109,7 +109,7 @@ static void bad_kernel_pc(struct pt_regs *regs)
  * this. Additionally, to prevent kswapd from ripping ptes from
  * under us, raise interrupts around the time that we look at the
  * pte, kswapd will have to wait to get his smp ipi response from
- * us. This saves us having to get page_table_lock.
+ * us. vmtruncate likewise. This saves us having to get pte lock.
  */
 static unsigned int get_user_insn(unsigned long tpc)
 {
@@ -139,7 +139,7 @@ static unsigned int get_user_insn(unsigned long tpc)
        if (!pte_present(pte))
                goto out;
 
-       pa  = (pte_val(pte) & _PAGE_PADDR);
+       pa  = (pte_pfn(pte) << PAGE_SHIFT);
        pa += (tpc & ~PAGE_MASK);
 
        /* Use phys bypass so we don't pollute dtlb/dcache. */
@@ -259,7 +259,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
        struct vm_area_struct *vma;
        unsigned int insn = 0;
        int si_code, fault_code;
-       unsigned long address;
+       unsigned long address, mm_rss;
 
        fault_code = get_thread_fault_code();
 
@@ -282,7 +282,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
                    (tpc >= MODULES_VADDR && tpc < MODULES_END)) {
                        /* Valid, no problems... */
                } else {
-                       bad_kernel_pc(regs);
+                       bad_kernel_pc(regs, address);
                        return;
                }
        }
@@ -327,8 +327,12 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
                insn = get_fault_insn(regs, 0);
                if (!insn)
                        goto continue_fault;
+               /* All loads, stores and atomics have bits 30 and 31 both set
+                * in the instruction.  Bit 21 is set in all stores, but we
+                * have to avoid prefetches which also have bit 21 set.
+                */
                if ((insn & 0xc0200000) == 0xc0200000 &&
-                   (insn & 0x1780000) != 0x1680000) {
+                   (insn & 0x01780000) != 0x01680000) {
                        /* Don't bother updating thread struct value,
                         * because update_mmu_cache only cares which tlb
                         * the access came from.
@@ -408,6 +412,20 @@ good_area:
        }
 
        up_read(&mm->mmap_sem);
+
+       mm_rss = get_mm_rss(mm);
+#ifdef CONFIG_HUGETLB_PAGE
+       mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE));
+#endif
+       if (unlikely(mm_rss >
+                    mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
+               tsb_grow(mm, MM_TSB_BASE, mm_rss);
+#ifdef CONFIG_HUGETLB_PAGE
+       mm_rss = mm->context.huge_pte_count;
+       if (unlikely(mm_rss >
+                    mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit))
+               tsb_grow(mm, MM_TSB_HUGE, mm_rss);
+#endif
        return;
 
        /*