From 811d50cb43eb730cc325df0c6913556e25739797 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 20 Nov 2007 17:01:55 +0900 Subject: sh: Move in the SH-5 TLB miss. Signed-off-by: Paul Mundt --- arch/sh/mm/Makefile_32 | 2 +- arch/sh/mm/Makefile_64 | 2 +- arch/sh/mm/fault.c | 303 ------------------------------------------------- arch/sh/mm/fault_32.c | 303 +++++++++++++++++++++++++++++++++++++++++++++++++ arch/sh/mm/fault_64.c | 279 +++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 584 insertions(+), 305 deletions(-) delete mode 100644 arch/sh/mm/fault.c create mode 100644 arch/sh/mm/fault_32.c create mode 100644 arch/sh/mm/fault_64.c (limited to 'arch/sh/mm') diff --git a/arch/sh/mm/Makefile_32 b/arch/sh/mm/Makefile_32 index 9ea379303742..fc089c0cdbe9 100644 --- a/arch/sh/mm/Makefile_32 +++ b/arch/sh/mm/Makefile_32 @@ -12,7 +12,7 @@ obj-$(CONFIG_SH7705_CACHE_32KB) += cache-sh7705.o endif mmu-y := tlb-nommu.o pg-nommu.o -mmu-$(CONFIG_MMU) := fault.o clear_page.o copy_page.o tlb-flush_32.o \ +mmu-$(CONFIG_MMU) := fault_32.o clear_page.o copy_page.o tlb-flush_32.o \ ioremap_32.o obj-y += $(mmu-y) diff --git a/arch/sh/mm/Makefile_64 b/arch/sh/mm/Makefile_64 index ec8deaa17909..82fe9072fd5c 100644 --- a/arch/sh/mm/Makefile_64 +++ b/arch/sh/mm/Makefile_64 @@ -5,7 +5,7 @@ obj-y := init.o extable_64.o consistent.o mmu-y := tlb-nommu.o pg-nommu.o -mmu-$(CONFIG_MMU) := ioremap_64.o tlb-flush_64.o +mmu-$(CONFIG_MMU) := fault_64.o ioremap_64.o tlb-flush_64.o obj-y += $(mmu-y) diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c deleted file mode 100644 index 60d74f793a1d..000000000000 --- a/arch/sh/mm/fault.c +++ /dev/null @@ -1,303 +0,0 @@ -/* - * Page fault handler for SH with an MMU. - * - * Copyright (C) 1999 Niibe Yutaka - * Copyright (C) 2003 - 2007 Paul Mundt - * - * Based on linux/arch/i386/mm/fault.c: - * Copyright (C) 1995 Linus Torvalds - * - * 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. - */ -#include -#include -#include -#include -#include -#include -#include -#include - -/* - * 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 __kprobes do_page_fault(struct pt_regs *regs, - unsigned long writeaccess, - unsigned long address) -{ - struct task_struct *tsk; - struct mm_struct *mm; - struct vm_area_struct * vma; - int si_code; - int fault; - siginfo_t info; - - trace_hardirqs_on(); - local_irq_enable(); - -#ifdef CONFIG_SH_KGDB - if (kgdb_nofault && kgdb_bus_err_hook) - kgdb_bus_err_hook(); -#endif - - tsk = current; - mm = tsk->mm; - si_code = SEGV_MAPERR; - - if (unlikely(address >= TASK_SIZE)) { - /* - * Synchronize this task's top level page-table - * with the 'reference' page table. - * - * Do _not_ use "tsk" here. We might be inside - * an interrupt in the middle of a task switch.. - */ - int offset = pgd_index(address); - pgd_t *pgd, *pgd_k; - pud_t *pud, *pud_k; - pmd_t *pmd, *pmd_k; - - pgd = get_TTB() + offset; - pgd_k = swapper_pg_dir + offset; - - /* This will never happen with the folded page table. */ - if (!pgd_present(*pgd)) { - if (!pgd_present(*pgd_k)) - goto bad_area_nosemaphore; - set_pgd(pgd, *pgd_k); - return; - } - - pud = pud_offset(pgd, address); - pud_k = pud_offset(pgd_k, address); - if (pud_present(*pud) || !pud_present(*pud_k)) - goto bad_area_nosemaphore; - set_pud(pud, *pud_k); - - pmd = pmd_offset(pud, address); - pmd_k = pmd_offset(pud_k, address); - if (pmd_present(*pmd) || !pmd_present(*pmd_k)) - goto bad_area_nosemaphore; - set_pmd(pmd, *pmd_k); - - return; - } - - /* - * If we're in an interrupt or have no user - * context, we must not take the fault.. - */ - if (in_atomic() || !mm) - goto no_context; - - down_read(&mm->mmap_sem); - - vma = find_vma(mm, address); - if (!vma) - goto bad_area; - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; -/* - * Ok, we have a good vm_area for this memory access, so - * we can handle it.. - */ -good_area: - si_code = SEGV_ACCERR; - if (writeaccess) { - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; - } else { - if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) - 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: - fault = handle_mm_fault(mm, vma, address, writeaccess); - if (unlikely(fault & VM_FAULT_ERROR)) { - if (fault & VM_FAULT_OOM) - goto out_of_memory; - else if (fault & VM_FAULT_SIGBUS) - goto do_sigbus; - BUG(); - } - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; - - 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: - up_read(&mm->mmap_sem); - -bad_area_nosemaphore: - if (user_mode(regs)) { - info.si_signo = SIGSEGV; - info.si_errno = 0; - info.si_code = si_code; - info.si_addr = (void *) address; - force_sig_info(SIGSEGV, &info, tsk); - return; - } - -no_context: - /* Are we prepared to handle this kernel fault? */ - if (fixup_exception(regs)) - return; - -/* - * Oops. The kernel tried to access some bad page. We'll have to - * terminate things with extreme prejudice. - * - */ - - bust_spinlocks(1); - - if (oops_may_print()) { - __typeof__(pte_val(__pte(0))) page; - - 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\n", regs->pc); - page = (unsigned long)get_TTB(); - if (page) { - page = ((__typeof__(page) *)page)[address >> PGDIR_SHIFT]; - printk(KERN_ALERT "*pde = %08lx\n", page); - if (page & _PAGE_PRESENT) { - page &= PAGE_MASK; - address &= 0x003ff000; - page = ((__typeof__(page) *) - __va(page))[address >> - PAGE_SHIFT]; - printk(KERN_ALERT "*pte = %08lx\n", page); - } - } - } - - die("Oops", regs, writeaccess); - bust_spinlocks(0); - 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: - up_read(&mm->mmap_sem); - if (is_global_init(current)) { - yield(); - down_read(&mm->mmap_sem); - goto survive; - } - printk("VM: killing process %s\n", tsk->comm); - if (user_mode(regs)) - do_group_exit(SIGKILL); - goto no_context; - -do_sigbus: - up_read(&mm->mmap_sem); - - /* - * Send a sigbus, regardless of whether we were in kernel - * or user mode. - */ - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRERR; - info.si_addr = (void *)address; - force_sig_info(SIGBUS, &info, tsk); - - /* Kernel mode? Handle exceptions or die */ - 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; - -#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); - } else { - if (unlikely(address >= TASK_SIZE || !current->mm)) - return 1; - - pgd = pgd_offset(current->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; - - pte = pte_offset_kernel(pmd, address); - entry = *pte; - if (unlikely(pte_none(entry) || pte_not_present(entry))) - return 1; - if (unlikely(writeaccess && !pte_write(entry))) - return 1; - - if (writeaccess) - entry = pte_mkdirty(entry); - entry = pte_mkyoung(entry); - - set_pte(pte, entry); - update_mmu_cache(NULL, address, entry); - - return 0; -} diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c new file mode 100644 index 000000000000..60d74f793a1d --- /dev/null +++ b/arch/sh/mm/fault_32.c @@ -0,0 +1,303 @@ +/* + * Page fault handler for SH with an MMU. + * + * Copyright (C) 1999 Niibe Yutaka + * Copyright (C) 2003 - 2007 Paul Mundt + * + * Based on linux/arch/i386/mm/fault.c: + * Copyright (C) 1995 Linus Torvalds + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * 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 __kprobes do_page_fault(struct pt_regs *regs, + unsigned long writeaccess, + unsigned long address) +{ + struct task_struct *tsk; + struct mm_struct *mm; + struct vm_area_struct * vma; + int si_code; + int fault; + siginfo_t info; + + trace_hardirqs_on(); + local_irq_enable(); + +#ifdef CONFIG_SH_KGDB + if (kgdb_nofault && kgdb_bus_err_hook) + kgdb_bus_err_hook(); +#endif + + tsk = current; + mm = tsk->mm; + si_code = SEGV_MAPERR; + + if (unlikely(address >= TASK_SIZE)) { + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + * + * Do _not_ use "tsk" here. We might be inside + * an interrupt in the middle of a task switch.. + */ + int offset = pgd_index(address); + pgd_t *pgd, *pgd_k; + pud_t *pud, *pud_k; + pmd_t *pmd, *pmd_k; + + pgd = get_TTB() + offset; + pgd_k = swapper_pg_dir + offset; + + /* This will never happen with the folded page table. */ + if (!pgd_present(*pgd)) { + if (!pgd_present(*pgd_k)) + goto bad_area_nosemaphore; + set_pgd(pgd, *pgd_k); + return; + } + + pud = pud_offset(pgd, address); + pud_k = pud_offset(pgd_k, address); + if (pud_present(*pud) || !pud_present(*pud_k)) + goto bad_area_nosemaphore; + set_pud(pud, *pud_k); + + pmd = pmd_offset(pud, address); + pmd_k = pmd_offset(pud_k, address); + if (pmd_present(*pmd) || !pmd_present(*pmd_k)) + goto bad_area_nosemaphore; + set_pmd(pmd, *pmd_k); + + return; + } + + /* + * If we're in an interrupt or have no user + * context, we must not take the fault.. + */ + if (in_atomic() || !mm) + goto no_context; + + down_read(&mm->mmap_sem); + + vma = find_vma(mm, address); + if (!vma) + goto bad_area; + if (vma->vm_start <= address) + goto good_area; + if (!(vma->vm_flags & VM_GROWSDOWN)) + goto bad_area; + if (expand_stack(vma, address)) + goto bad_area; +/* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ +good_area: + si_code = SEGV_ACCERR; + if (writeaccess) { + if (!(vma->vm_flags & VM_WRITE)) + goto bad_area; + } else { + if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) + 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: + fault = handle_mm_fault(mm, vma, address, writeaccess); + if (unlikely(fault & VM_FAULT_ERROR)) { + if (fault & VM_FAULT_OOM) + goto out_of_memory; + else if (fault & VM_FAULT_SIGBUS) + goto do_sigbus; + BUG(); + } + if (fault & VM_FAULT_MAJOR) + tsk->maj_flt++; + else + tsk->min_flt++; + + 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: + up_read(&mm->mmap_sem); + +bad_area_nosemaphore: + if (user_mode(regs)) { + info.si_signo = SIGSEGV; + info.si_errno = 0; + info.si_code = si_code; + info.si_addr = (void *) address; + force_sig_info(SIGSEGV, &info, tsk); + return; + } + +no_context: + /* Are we prepared to handle this kernel fault? */ + if (fixup_exception(regs)) + return; + +/* + * Oops. The kernel tried to access some bad page. We'll have to + * terminate things with extreme prejudice. + * + */ + + bust_spinlocks(1); + + if (oops_may_print()) { + __typeof__(pte_val(__pte(0))) page; + + 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\n", regs->pc); + page = (unsigned long)get_TTB(); + if (page) { + page = ((__typeof__(page) *)page)[address >> PGDIR_SHIFT]; + printk(KERN_ALERT "*pde = %08lx\n", page); + if (page & _PAGE_PRESENT) { + page &= PAGE_MASK; + address &= 0x003ff000; + page = ((__typeof__(page) *) + __va(page))[address >> + PAGE_SHIFT]; + printk(KERN_ALERT "*pte = %08lx\n", page); + } + } + } + + die("Oops", regs, writeaccess); + bust_spinlocks(0); + 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: + up_read(&mm->mmap_sem); + if (is_global_init(current)) { + yield(); + down_read(&mm->mmap_sem); + goto survive; + } + printk("VM: killing process %s\n", tsk->comm); + if (user_mode(regs)) + do_group_exit(SIGKILL); + goto no_context; + +do_sigbus: + up_read(&mm->mmap_sem); + + /* + * Send a sigbus, regardless of whether we were in kernel + * or user mode. + */ + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRERR; + info.si_addr = (void *)address; + force_sig_info(SIGBUS, &info, tsk); + + /* Kernel mode? Handle exceptions or die */ + 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; + +#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); + } else { + if (unlikely(address >= TASK_SIZE || !current->mm)) + return 1; + + pgd = pgd_offset(current->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; + + pte = pte_offset_kernel(pmd, address); + entry = *pte; + if (unlikely(pte_none(entry) || pte_not_present(entry))) + return 1; + if (unlikely(writeaccess && !pte_write(entry))) + return 1; + + if (writeaccess) + entry = pte_mkdirty(entry); + entry = pte_mkyoung(entry); + + set_pte(pte, entry); + update_mmu_cache(NULL, address, entry); + + return 0; +} diff --git a/arch/sh/mm/fault_64.c b/arch/sh/mm/fault_64.c new file mode 100644 index 000000000000..1469aa70bc78 --- /dev/null +++ b/arch/sh/mm/fault_64.c @@ -0,0 +1,279 @@ +/* + * The SH64 TLB miss. + * + * Original code from fault.c + * Copyright (C) 2000, 2001 Paolo Alberelli + * + * Fast PTE->TLB refill path + * Copyright (C) 2003 Richard.Curnow@superh.com + * + * IMPORTANT NOTES : + * The do_fast_page_fault function is called from a context in entry.S + * where very few registers have been saved. In particular, the code in + * this file must be compiled not to use ANY caller-save registers that + * are not part of the restricted save set. Also, it means that code in + * this file must not make calls to functions elsewhere in the kernel, or + * else the excepting context will see corruption in its caller-save + * registers. Plus, the entry.S save area is non-reentrant, so this code + * has to run with SR.BL==1, i.e. no interrupts taken inside it and panic + * on any exception. + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Callable from fault.c, so not static */ +inline void __do_tlb_refill(unsigned long address, + unsigned long long is_text_not_data, pte_t *pte) +{ + unsigned long long ptel; + unsigned long long pteh=0; + struct tlb_info *tlbp; + unsigned long long next; + + /* Get PTEL first */ + ptel = pte_val(*pte); + + /* + * Set PTEH register + */ + pteh = address & MMU_VPN_MASK; + + /* Sign extend based on neff. */ +#if (NEFF == 32) + /* Faster sign extension */ + pteh = (unsigned long long)(signed long long)(signed long)pteh; +#else + /* General case */ + pteh = (pteh & NEFF_SIGN) ? (pteh | NEFF_MASK) : pteh; +#endif + + /* Set the ASID. */ + pteh |= get_asid() << PTEH_ASID_SHIFT; + pteh |= PTEH_VALID; + + /* Set PTEL register, set_pte has performed the sign extension */ + ptel &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */ + + tlbp = is_text_not_data ? &(cpu_data->itlb) : &(cpu_data->dtlb); + next = tlbp->next; + __flush_tlb_slot(next); + asm volatile ("putcfg %0,1,%2\n\n\t" + "putcfg %0,0,%1\n" + : : "r" (next), "r" (pteh), "r" (ptel) ); + + next += TLB_STEP; + if (next > tlbp->last) next = tlbp->first; + tlbp->next = next; + +} + +static int handle_vmalloc_fault(struct mm_struct *mm, + unsigned long protection_flags, + unsigned long long textaccess, + unsigned long address) +{ + pgd_t *dir; + pud_t *pud; + pmd_t *pmd; + static pte_t *pte; + pte_t entry; + + dir = pgd_offset_k(address); + + pud = pud_offset(dir, address); + if (pud_none_or_clear_bad(pud)) + return 0; + + pmd = pmd_offset(pud, address); + if (pmd_none_or_clear_bad(pmd)) + return 0; + + pte = pte_offset_kernel(pmd, address); + entry = *pte; + + if (pte_none(entry) || !pte_present(entry)) + return 0; + if ((pte_val(entry) & protection_flags) != protection_flags) + return 0; + + __do_tlb_refill(address, textaccess, pte); + + return 1; +} + +static int handle_tlbmiss(struct mm_struct *mm, + unsigned long long protection_flags, + unsigned long long textaccess, + unsigned long address) +{ + pgd_t *dir; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + pte_t entry; + + /* NB. The PGD currently only contains a single entry - there is no + page table tree stored for the top half of the address space since + virtual pages in that region should never be mapped in user mode. + (In kernel mode, the only things in that region are the 512Mb super + page (locked in), and vmalloc (modules) + I/O device pages (handled + by handle_vmalloc_fault), so no PGD for the upper half is required + by kernel mode either). + + See how mm->pgd is allocated and initialised in pgd_alloc to see why + the next test is necessary. - RPC */ + if (address >= (unsigned long) TASK_SIZE) + /* upper half - never has page table entries. */ + return 0; + + dir = pgd_offset(mm, address); + if (pgd_none(*dir) || !pgd_present(*dir)) + return 0; + if (!pgd_present(*dir)) + return 0; + + pud = pud_offset(dir, address); + if (pud_none(*pud) || !pud_present(*pud)) + return 0; + + pmd = pmd_offset(pud, address); + if (pmd_none(*pmd) || !pmd_present(*pmd)) + return 0; + + pte = pte_offset_kernel(pmd, address); + entry = *pte; + + if (pte_none(entry) || !pte_present(entry)) + return 0; + + /* + * If the page doesn't have sufficient protection bits set to + * service the kind of fault being handled, there's not much + * point doing the TLB refill. Punt the fault to the general + * handler. + */ + if ((pte_val(entry) & protection_flags) != protection_flags) + return 0; + + __do_tlb_refill(address, textaccess, pte); + + return 1; +} + +/* + * Put all this information into one structure so that everything is just + * arithmetic relative to a single base address. This reduces the number + * of movi/shori pairs needed just to load addresses of static data. + */ +struct expevt_lookup { + unsigned short protection_flags[8]; + unsigned char is_text_access[8]; + unsigned char is_write_access[8]; +}; + +#define PRU (1<<9) +#define PRW (1<<8) +#define PRX (1<<7) +#define PRR (1<<6) + +#define DIRTY (_PAGE_DIRTY | _PAGE_ACCESSED) +#define YOUNG (_PAGE_ACCESSED) + +/* Sized as 8 rather than 4 to allow checking the PTE's PRU bit against whether + the fault happened in user mode or privileged mode. */ +static struct expevt_lookup expevt_lookup_table = { + .protection_flags = {PRX, PRX, 0, 0, PRR, PRR, PRW, PRW}, + .is_text_access = {1, 1, 0, 0, 0, 0, 0, 0} +}; + +/* + This routine handles page faults that can be serviced just by refilling a + TLB entry from an existing page table entry. (This case represents a very + large majority of page faults.) Return 1 if the fault was successfully + handled. Return 0 if the fault could not be handled. (This leads into the + general fault handling in fault.c which deals with mapping file-backed + pages, stack growth, segmentation faults, swapping etc etc) + */ +asmlinkage int do_fast_page_fault(unsigned long long ssr_md, + unsigned long long expevt, + unsigned long address) +{ + struct task_struct *tsk; + struct mm_struct *mm; + unsigned long long textaccess; + unsigned long long protection_flags; + unsigned long long index; + unsigned long long expevt4; + + /* The next few lines implement a way of hashing EXPEVT into a + * small array index which can be used to lookup parameters + * specific to the type of TLBMISS being handled. + * + * Note: + * ITLBMISS has EXPEVT==0xa40 + * RTLBMISS has EXPEVT==0x040 + * WTLBMISS has EXPEVT==0x060 + */ + expevt4 = (expevt >> 4); + /* TODO : xor ssr_md into this expression too. Then we can check + * that PRU is set when it needs to be. */ + index = expevt4 ^ (expevt4 >> 5); + index &= 7; + protection_flags = expevt_lookup_table.protection_flags[index]; + textaccess = expevt_lookup_table.is_text_access[index]; + +#ifdef CONFIG_SH64_PROC_TLB + ++calls_to_do_fast_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 interrupts 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; + + if ((address >= VMALLOC_START && address < VMALLOC_END) || + (address >= IOBASE_VADDR && address < IOBASE_END)) { + if (ssr_md) + /* + * Process-contexts can never have this address + * range mapped + */ + if (handle_vmalloc_fault(mm, protection_flags, + textaccess, address)) + return 1; + } else if (!in_interrupt() && mm) { + if (handle_tlbmiss(mm, protection_flags, textaccess, address)) + return 1; + } + + return 0; +} -- cgit v1.2.3