/*
- * 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
+ * The SH64 TLB miss.
*
* Original code from fault.c
* Copyright (C) 2000, 2001 Paolo Alberelli
* 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.
+ * 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/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 */
+#include <asm/cpu/registers.h>
/* Callable from fault.c, so not static */
inline void __do_tlb_refill(unsigned long address,
}
-static int handle_vmalloc_fault(struct mm_struct *mm, unsigned long protection_flags,
+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);
- pmd = pmd_offset(dir, address);
- if (pmd_none(*pmd)) {
+ pud = pud_offset(dir, address);
+ if (pud_none_or_clear_bad(pud))
return 0;
- }
- if (pmd_bad(*pmd)) {
- pmd_clear(pmd);
+ 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)) {
+ if (pte_none(entry) || !pte_present(entry))
return 0;
- }
-
- if ((pte_val(entry) & protection_flags) != protection_flags) {
+ 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)
+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;
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) {
+ if (address >= (unsigned long) TASK_SIZE)
/* upper half - never has page table entries. */
return 0;
- }
+
dir = pgd_offset(mm, address);
- if (pgd_none(*dir)) {
+ if (pgd_none(*dir) || !pgd_present(*dir))
return 0;
- }
- if (!pgd_present(*dir)) {
+ if (!pgd_present(*dir))
return 0;
- }
- pmd = pmd_offset(dir, address);
- if (pmd_none(*pmd)) {
+ pud = pud_offset(dir, address);
+ if (pud_none(*pud) || !pud_present(*pud))
return 0;
- }
- if (!pmd_present(*pmd)) {
+
+ 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)) {
- return 0;
- }
- if (!pte_present(entry)) {
+
+ 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) {
+ /*
+ * 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. */
+/*
+ * 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];
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,
+asmlinkage int do_fast_page_fault(unsigned long long ssr_md,
+ unsigned long long expevt,
unsigned long address)
{
struct task_struct *tsk;
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
- */
-
+ /* 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. */
+ /* 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];
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)) {
+ 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)) {
+ if (handle_tlbmiss(mm, protection_flags, textaccess, address))
return 1;
- }
}
return 0;
}
-
projects / platform / kernel / linux-rpi.git / commitdiff