1 files changed, 601 insertions, 0 deletions

diff --git a/arch/sh64/mm/fault.c b/arch/sh64/mm/fault.c
new file mode 100644
index 000000000000..a24932881dbb
--- /dev/null
+++ b/arch/sh64/mm/fault.c
@@ -0,0 +1,601 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * arch/sh64/mm/fault.c
+ *
+ * Copyright (C) 2000, 2001  Paolo Alberelli
+ * Copyright (C) 2003  Richard Curnow (/proc/tlb, bug fixes)
+ * Copyright (C) 2003  Paul Mundt
+ *
+ */
+
+#include <linux/signal.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/tlb.h>
+#include <asm/uaccess.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu_context.h>
+#include <asm/registers.h>              /* required by inline asm statements */
+
+#if defined(CONFIG_SH64_PROC_TLB)
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+/* Count numbers of tlb refills in each region */
+static unsigned long long calls_to_update_mmu_cache = 0ULL;
+static unsigned long long calls_to_flush_tlb_page   = 0ULL;
+static unsigned long long calls_to_flush_tlb_range  = 0ULL;
+static unsigned long long calls_to_flush_tlb_mm     = 0ULL;
+static unsigned long long calls_to_flush_tlb_all    = 0ULL;
+unsigned long long calls_to_do_slow_page_fault = 0ULL;
+unsigned long long calls_to_do_fast_page_fault = 0ULL;
+
+/* Count size of ranges for flush_tlb_range */
+static unsigned long long flush_tlb_range_1         = 0ULL;
+static unsigned long long flush_tlb_range_2         = 0ULL;
+static unsigned long long flush_tlb_range_3_4       = 0ULL;
+static unsigned long long flush_tlb_range_5_7       = 0ULL;
+static unsigned long long flush_tlb_range_8_11      = 0ULL;
+static unsigned long long flush_tlb_range_12_15     = 0ULL;
+static unsigned long long flush_tlb_range_16_up     = 0ULL;
+
+static unsigned long long page_not_present          = 0ULL;
+
+#endif
+
+extern void die(const char *,struct pt_regs *,long);
+
+#define PFLAG(val,flag)   (( (val) & (flag) ) ? #flag : "" )
+#define PPROT(flag) PFLAG(pgprot_val(prot),flag)
+
+static inline void print_prots(pgprot_t prot)
+{
+        printk("prot is 0x%08lx\n",pgprot_val(prot));
+
+        printk("%s %s %s %s %s\n",PPROT(_PAGE_SHARED),PPROT(_PAGE_READ),
+               PPROT(_PAGE_EXECUTE),PPROT(_PAGE_WRITE),PPROT(_PAGE_USER));
+}
+
+static inline void print_vma(struct vm_area_struct *vma)
+{
+        printk("vma start 0x%08lx\n", vma->vm_start);
+        printk("vma end   0x%08lx\n", vma->vm_end);
+
+        print_prots(vma->vm_page_prot);
+        printk("vm_flags 0x%08lx\n", vma->vm_flags);
+}
+
+static inline void print_task(struct task_struct *tsk)
+{
+        printk("Task pid %d\n", tsk->pid);
+}
+
+static pte_t *lookup_pte(struct mm_struct *mm, unsigned long address)
+{
+        pgd_t *dir;
+        pmd_t *pmd;
+        pte_t *pte;
+        pte_t entry;
+
+        dir = pgd_offset(mm, address);
+        if (pgd_none(*dir)) {
+                return NULL;
+        }
+
+        pmd = pmd_offset(dir, address);
+        if (pmd_none(*pmd)) {
+                return NULL;
+        }
+
+        pte = pte_offset_kernel(pmd, address);
+        entry = *pte;
+
+        if (pte_none(entry)) {
+                return NULL;
+        }
+        if (!pte_present(entry)) {
+                return NULL;
+        }
+
+        return pte;
+}
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
+                              unsigned long textaccess, unsigned long address)
+{
+        struct task_struct *tsk;
+        struct mm_struct *mm;
+        struct vm_area_struct * vma;
+        const struct exception_table_entry *fixup;
+        pte_t *pte;
+
+#if defined(CONFIG_SH64_PROC_TLB)
+        ++calls_to_do_slow_page_fault;
+#endif
+
+        /* SIM
+         * Note this is now called with interrupts still disabled
+         * This is to cope with being called for a missing IO port
+         * address with interupts disabled. This should be fixed as
+         * soon as we have a better 'fast path' miss handler.
+         *
+         * Plus take care how you try and debug this stuff.
+         * For example, writing debug data to a port which you
+         * have just faulted on is not going to work.
+         */
+
+        tsk = current;
+        mm = tsk->mm;
+
+        /* Not an IO address, so reenable interrupts */
+        local_irq_enable();
+
+        /*
+         * If we're in an interrupt or have no user
+         * context, we must not take the fault..
+         */
+        if (in_interrupt() || !mm)
+                goto no_context;
+
+        /* TLB misses upon some cache flushes get done under cli() */
+        down_read(&mm->mmap_sem);
+
+        vma = find_vma(mm, address);
+
+        if (!vma) {
+#ifdef DEBUG_FAULT
+                print_task(tsk);
+                printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
+                       __FUNCTION__,__LINE__,
+                       address,regs->pc,textaccess,writeaccess);
+                show_regs(regs);
+#endif
+                goto bad_area;
+        }
+        if (vma->vm_start <= address) {
+                goto good_area;
+        }
+
+        if (!(vma->vm_flags & VM_GROWSDOWN)) {
+#ifdef DEBUG_FAULT
+                print_task(tsk);
+                printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
+                       __FUNCTION__,__LINE__,
+                       address,regs->pc,textaccess,writeaccess);
+                show_regs(regs);
+
+                print_vma(vma);
+#endif
+                goto bad_area;
+        }
+        if (expand_stack(vma, address)) {
+#ifdef DEBUG_FAULT
+                print_task(tsk);
+                printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
+                       __FUNCTION__,__LINE__,
+                       address,regs->pc,textaccess,writeaccess);
+                show_regs(regs);
+#endif
+                goto bad_area;
+        }
+/*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
+good_area:
+        if (textaccess) {
+                if (!(vma->vm_flags & VM_EXEC))
+                        goto bad_area;
+        } else {
+                if (writeaccess) {
+                        if (!(vma->vm_flags & VM_WRITE))
+                                goto bad_area;
+                } else {
+                        if (!(vma->vm_flags & VM_READ))
+                                goto bad_area;
+                }
+        }
+
+        /*
+         * If for any reason at all we couldn't handle the fault,
+         * make sure we exit gracefully rather than endlessly redo
+         * the fault.
+         */
+survive:
+        switch (handle_mm_fault(mm, vma, address, writeaccess)) {
+        case 1:
+                tsk->min_flt++;
+                break;
+        case 2:
+                tsk->maj_flt++;
+                break;
+        case 0:
+                goto do_sigbus;
+        default:
+                goto out_of_memory;
+        }
+        /* If we get here, the page fault has been handled.  Do the TLB refill
+           now from the newly-setup PTE, to avoid having to fault again right
+           away on the same instruction. */
+        pte = lookup_pte (mm, address);
+        if (!pte) {
+                /* From empirical evidence, we can get here, due to
+                   !pte_present(pte).  (e.g. if a swap-in occurs, and the page
+                   is swapped back out again before the process that wanted it
+                   gets rescheduled?) */
+                goto no_pte;
+        }
+
+        __do_tlb_refill(address, textaccess, pte);
+
+no_pte:
+
+        up_read(&mm->mmap_sem);
+        return;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+bad_area:
+#ifdef DEBUG_FAULT
+        printk("fault:bad area\n");
+#endif
+        up_read(&mm->mmap_sem);
+
+        if (user_mode(regs)) {
+                static int count=0;
+                siginfo_t info;
+                if (count < 4) {
+                        /* This is really to help debug faults when starting
+                         * usermode, so only need a few */
+                        count++;
+                        printk("user mode bad_area address=%08lx pid=%d (%s) pc=%08lx\n",
+                                address, current->pid, current->comm,
+                                (unsigned long) regs->pc);
+#if 0
+                        show_regs(regs);
+#endif
+                }
+                if (tsk->pid == 1) {
+                        panic("INIT had user mode bad_area\n");
+                }
+                tsk->thread.address = address;
+                tsk->thread.error_code = writeaccess;
+                info.si_signo = SIGSEGV;
+                info.si_errno = 0;
+                info.si_addr = (void *) address;
+                force_sig_info(SIGSEGV, &info, tsk);
+                return;
+        }
+
+no_context:
+#ifdef DEBUG_FAULT
+        printk("fault:No context\n");
+#endif
+        /* Are we prepared to handle this kernel fault?  */
+        fixup = search_exception_tables(regs->pc);
+        if (fixup) {
+                regs->pc = fixup->fixup;
+                return;
+        }
+
+/*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ *
+ */
+        if (address < PAGE_SIZE)
+                printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
+        else
+                printk(KERN_ALERT "Unable to handle kernel paging request");
+        printk(" at virtual address %08lx\n", address);
+        printk(KERN_ALERT "pc = %08Lx%08Lx\n", regs->pc >> 32, regs->pc & 0xffffffff);
+        die("Oops", regs, writeaccess);
+        do_exit(SIGKILL);
+
+/*
+ * We ran out of memory, or some other thing happened to us that made
+ * us unable to handle the page fault gracefully.
+ */
+out_of_memory:
+        if (current->pid == 1) {
+                panic("INIT out of memory\n");
+                yield();
+                goto survive;
+        }
+        printk("fault:Out of memory\n");
+        up_read(&mm->mmap_sem);
+        if (current->pid == 1) {
+                yield();
+                down_read(&mm->mmap_sem);
+                goto survive;
+        }
+        printk("VM: killing process %s\n", tsk->comm);
+        if (user_mode(regs))
+                do_exit(SIGKILL);
+        goto no_context;
+
+do_sigbus:
+        printk("fault:Do sigbus\n");
+        up_read(&mm->mmap_sem);
+
+        /*
+         * Send a sigbus, regardless of whether we were in kernel
+         * or user mode.
+         */
+        tsk->thread.address = address;
+        tsk->thread.error_code = writeaccess;
+        tsk->thread.trap_no = 14;
+        force_sig(SIGBUS, tsk);
+
+        /* Kernel mode? Handle exceptions or die */
+        if (!user_mode(regs))
+                goto no_context;
+}
+
+
+void flush_tlb_all(void);
+
+void update_mmu_cache(struct vm_area_struct * vma,
+                        unsigned long address, pte_t pte)
+{
+#if defined(CONFIG_SH64_PROC_TLB)
+        ++calls_to_update_mmu_cache;
+#endif
+
+        /*
+         * This appears to get called once for every pte entry that gets
+         * established => I don't think it's efficient to try refilling the
+         * TLBs with the pages - some may not get accessed even.  Also, for
+         * executable pages, it is impossible to determine reliably here which
+         * TLB they should be mapped into (or both even).
+         *
+         * So, just do nothing here and handle faults on demand.  In the
+         * TLBMISS handling case, the refill is now done anyway after the pte
+         * has been fixed up, so that deals with most useful cases.
+         */
+}
+
+static void __flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+        unsigned long long match, pteh=0, lpage;
+        unsigned long tlb;
+        struct mm_struct *mm;
+
+        mm = vma->vm_mm;
+
+        if (mm->context == NO_CONTEXT)
+                return;
+
+        /*
+         * Sign-extend based on neff.
+         */
+        lpage = (page & NEFF_SIGN) ? (page | NEFF_MASK) : page;
+        match = ((mm->context & MMU_CONTEXT_ASID_MASK) << PTEH_ASID_SHIFT) | PTEH_VALID;
+        match |= lpage;
+
+        /* Do ITLB : don't bother for pages in non-exectutable VMAs */
+        if (vma->vm_flags & VM_EXEC) {
+                for_each_itlb_entry(tlb) {
+                        asm volatile ("getcfg   %1, 0, %0"
+                                      : "=r" (pteh)
+                                      : "r" (tlb) );
+
+                        if (pteh == match) {
+                                __flush_tlb_slot(tlb);
+                                break;
+                        }
+
+                }
+        }
+
+        /* Do DTLB : any page could potentially be in here. */
+        for_each_dtlb_entry(tlb) {
+                asm volatile ("getcfg   %1, 0, %0"
+                              : "=r" (pteh)
+                              : "r" (tlb) );
+
+                if (pteh == match) {
+                        __flush_tlb_slot(tlb);
+                        break;
+                }
+
+        }
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+        unsigned long flags;
+
+#if defined(CONFIG_SH64_PROC_TLB)
+        ++calls_to_flush_tlb_page;
+#endif
+
+        if (vma->vm_mm) {
+                page &= PAGE_MASK;
+                local_irq_save(flags);
+                __flush_tlb_page(vma, page);
+                local_irq_restore(flags);
+        }
+}
+
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+                     unsigned long end)
+{
+        unsigned long flags;
+        unsigned long long match, pteh=0, pteh_epn, pteh_low;
+        unsigned long tlb;
+        struct mm_struct *mm;
+
+        mm = vma->vm_mm;
+
+#if defined(CONFIG_SH64_PROC_TLB)
+        ++calls_to_flush_tlb_range;
+
+        {
+                unsigned long size = (end - 1) - start;
+                size >>= 12; /* divide by PAGE_SIZE */
+                size++; /* end=start+4096 => 1 page */
+                switch (size) {
+                  case  1        : flush_tlb_range_1++;     break;
+                  case  2        : flush_tlb_range_2++;     break;
+                  case  3 ...  4 : flush_tlb_range_3_4++;   break;
+                  case  5 ...  7 : flush_tlb_range_5_7++;   break;
+                  case  8 ... 11 : flush_tlb_range_8_11++;  break;
+                  case 12 ... 15 : flush_tlb_range_12_15++; break;
+                  default        : flush_tlb_range_16_up++; break;
+                }
+        }
+#endif
+
+        if (mm->context == NO_CONTEXT)
+                return;
+
+        local_irq_save(flags);
+
+        start &= PAGE_MASK;
+        end &= PAGE_MASK;
+
+        match = ((mm->context & MMU_CONTEXT_ASID_MASK) << PTEH_ASID_SHIFT) | PTEH_VALID;
+
+        /* Flush ITLB */
+        for_each_itlb_entry(tlb) {
+                asm volatile ("getcfg   %1, 0, %0"
+                              : "=r" (pteh)
+                              : "r" (tlb) );
+
+                pteh_epn = pteh & PAGE_MASK;
+                pteh_low = pteh & ~PAGE_MASK;
+
+                if (pteh_low == match && pteh_epn >= start && pteh_epn <= end)
+                        __flush_tlb_slot(tlb);
+        }
+
+        /* Flush DTLB */
+        for_each_dtlb_entry(tlb) {
+                asm volatile ("getcfg   %1, 0, %0"
+                              : "=r" (pteh)
+                              : "r" (tlb) );
+
+                pteh_epn = pteh & PAGE_MASK;
+                pteh_low = pteh & ~PAGE_MASK;
+
+                if (pteh_low == match && pteh_epn >= start && pteh_epn <= end)
+                        __flush_tlb_slot(tlb);
+        }
+
+        local_irq_restore(flags);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+        unsigned long flags;
+
+#if defined(CONFIG_SH64_PROC_TLB)
+        ++calls_to_flush_tlb_mm;
+#endif
+
+        if (mm->context == NO_CONTEXT)
+                return;
+
+        local_irq_save(flags);
+
+        mm->context=NO_CONTEXT;
+        if(mm==current->mm)
+                activate_context(mm);
+
+        local_irq_restore(flags);
+
+}
+
+void flush_tlb_all(void)
+{
+        /* Invalidate all, including shared pages, excluding fixed TLBs */
+
+        unsigned long flags, tlb;
+
+#if defined(CONFIG_SH64_PROC_TLB)
+        ++calls_to_flush_tlb_all;
+#endif
+
+        local_irq_save(flags);
+
+        /* Flush each ITLB entry */
+        for_each_itlb_entry(tlb) {
+                __flush_tlb_slot(tlb);
+        }
+
+        /* Flush each DTLB entry */
+        for_each_dtlb_entry(tlb) {
+                __flush_tlb_slot(tlb);
+        }
+
+        local_irq_restore(flags);
+}
+
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+        /* FIXME: Optimize this later.. */
+        flush_tlb_all();
+}
+
+#if defined(CONFIG_SH64_PROC_TLB)
+/* Procfs interface to read the performance information */
+
+static int
+tlb_proc_info(char *buf, char **start, off_t fpos, int length, int *eof, void *data)
+{
+  int len=0;
+  len += sprintf(buf+len, "do_fast_page_fault   called %12lld times\n", calls_to_do_fast_page_fault);
+  len += sprintf(buf+len, "do_slow_page_fault   called %12lld times\n", calls_to_do_slow_page_fault);
+  len += sprintf(buf+len, "update_mmu_cache     called %12lld times\n", calls_to_update_mmu_cache);
+  len += sprintf(buf+len, "flush_tlb_page       called %12lld times\n", calls_to_flush_tlb_page);
+  len += sprintf(buf+len, "flush_tlb_range      called %12lld times\n", calls_to_flush_tlb_range);
+  len += sprintf(buf+len, "flush_tlb_mm         called %12lld times\n", calls_to_flush_tlb_mm);
+  len += sprintf(buf+len, "flush_tlb_all        called %12lld times\n", calls_to_flush_tlb_all);
+  len += sprintf(buf+len, "flush_tlb_range_sizes\n"
+                          " 1      : %12lld\n"
+                          " 2      : %12lld\n"
+                          " 3 -  4 : %12lld\n"
+                          " 5 -  7 : %12lld\n"
+                          " 8 - 11 : %12lld\n"
+                          "12 - 15 : %12lld\n"
+                          "16+     : %12lld\n",
+                          flush_tlb_range_1, flush_tlb_range_2, flush_tlb_range_3_4,
+                          flush_tlb_range_5_7, flush_tlb_range_8_11, flush_tlb_range_12_15,
+                          flush_tlb_range_16_up);
+  len += sprintf(buf+len, "page not present           %12lld times\n", page_not_present);
+  *eof = 1;
+  return len;
+}
+
+static int __init register_proc_tlb(void)
+{
+  create_proc_read_entry("tlb", 0, NULL, tlb_proc_info, NULL);
+  return 0;
+}
+
+__initcall(register_proc_tlb);
+
+#endif