diff options
Diffstat (limited to 'arch/sh64/mm')
| -rw-r--r-- | arch/sh64/mm/tlbmiss.c | 279 |
1 files changed, 0 insertions, 279 deletions
diff --git a/arch/sh64/mm/tlbmiss.c b/arch/sh64/mm/tlbmiss.c deleted file mode 100644 index b767d6cff72..00000000000 --- a/arch/sh64/mm/tlbmiss.c +++ /dev/null @@ -1,279 +0,0 @@ -/* - * 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/tlbmiss.c - * - * 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. - * - */ - -#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 <asm/registers.h> /* required by inline asm statements */ - -/* 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; - pmd_t *pmd; - static pte_t *pte; - pte_t entry; - - dir = pgd_offset_k(address); - pmd = pmd_offset(dir, address); - - if (pmd_none(*pmd)) { - return 0; - } - - if (pmd_bad(*pmd)) { - pmd_clear(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; - 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)) { - return 0; - } - if (!pgd_present(*dir)) { - return 0; - } - - pmd = pmd_offset(dir, address); - if (pmd_none(*pmd)) { - return 0; - } - if (!pmd_present(*pmd)) { - return 0; - } - pte = pte_offset_kernel(pmd, address); - entry = *pte; - if (pte_none(entry)) { - return 0; - } - if (!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; -} - |