aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/arch/sh64/mm/fault.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh64/mm/fault.c')
-rw-r--r--arch/sh64/mm/fault.c601
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
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.