diff options
Diffstat (limited to 'arch/sh64/mm/fault.c')
| -rw-r--r-- | arch/sh64/mm/fault.c | 601 |
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 |