diff options
Diffstat (limited to 'arch/sh/mm/fault_64.c')
| -rw-r--r-- | arch/sh/mm/fault_64.c | 266 |
1 files changed, 0 insertions, 266 deletions
diff --git a/arch/sh/mm/fault_64.c b/arch/sh/mm/fault_64.c deleted file mode 100644 index 2b356cec248..00000000000 --- a/arch/sh/mm/fault_64.c +++ /dev/null @@ -1,266 +0,0 @@ -/* - * 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 <linux/signal.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/interrupt.h> -#include <asm/system.h> -#include <asm/tlb.h> -#include <asm/io.h> -#include <asm/uaccess.h> -#include <asm/pgalloc.h> -#include <asm/mmu_context.h> -#include <cpu/registers.h> - -/* 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 = neff_sign_extend(address & MMU_VPN_MASK); - - /* 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]; - - /* 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; -} |