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sh64: Tidy up and consolidate the TLB miss fast path.
This unifies the fast-path TLB miss handler, allowing for further cleanup and eventual utilization of a shared _32/_64 handler. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt
parent
2ec08e141f
commit
392c3822a6
@ -33,76 +33,32 @@
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/interrupt.h>
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#include <linux/kprobes.h>
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#include <asm/tlb.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/pgalloc.h>
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#include <asm/mmu_context.h>
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static int handle_vmalloc_fault(struct mm_struct *mm,
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unsigned long protection_flags,
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unsigned long address)
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{
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pgd_t *dir;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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pte_t entry;
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dir = pgd_offset_k(address);
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pud = pud_offset(dir, address);
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if (pud_none_or_clear_bad(pud))
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return 1;
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pmd = pmd_offset(pud, address);
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if (pmd_none_or_clear_bad(pmd))
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return 1;
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pte = pte_offset_kernel(pmd, address);
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entry = *pte;
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if (pte_none(entry) || !pte_present(entry))
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return 1;
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if ((pte_val(entry) & protection_flags) != protection_flags)
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return 1;
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update_mmu_cache(NULL, address, pte);
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return 0;
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}
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static int handle_tlbmiss(struct mm_struct *mm,
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unsigned long long protection_flags,
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static int handle_tlbmiss(unsigned long long protection_flags,
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unsigned long address)
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{
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pgd_t *dir;
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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pte_t entry;
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/* NB. The PGD currently only contains a single entry - there is no
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page table tree stored for the top half of the address space since
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virtual pages in that region should never be mapped in user mode.
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(In kernel mode, the only things in that region are the 512Mb super
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page (locked in), and vmalloc (modules) + I/O device pages (handled
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by handle_vmalloc_fault), so no PGD for the upper half is required
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by kernel mode either).
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if (is_vmalloc_addr((void *)address)) {
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pgd = pgd_offset_k(address);
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} else {
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if (unlikely(address >= TASK_SIZE || !current->mm))
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return 1;
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See how mm->pgd is allocated and initialised in pgd_alloc to see why
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the next test is necessary. - RPC */
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if (address >= (unsigned long) TASK_SIZE)
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/* upper half - never has page table entries. */
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return 1;
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pgd = pgd_offset(current->mm, address);
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}
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dir = pgd_offset(mm, address);
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if (pgd_none(*dir) || !pgd_present(*dir))
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return 1;
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if (!pgd_present(*dir))
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return 1;
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pud = pud_offset(dir, address);
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pud = pud_offset(pgd, address);
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if (pud_none(*pud) || !pud_present(*pud))
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return 1;
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@ -112,7 +68,6 @@ static int handle_tlbmiss(struct mm_struct *mm,
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pte = pte_offset_kernel(pmd, address);
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entry = *pte;
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if (pte_none(entry) || !pte_present(entry))
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return 1;
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@ -146,9 +101,6 @@ struct expevt_lookup {
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#define PRX (1<<7)
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#define PRR (1<<6)
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#define DIRTY (_PAGE_DIRTY | _PAGE_ACCESSED)
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#define YOUNG (_PAGE_ACCESSED)
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/* Sized as 8 rather than 4 to allow checking the PTE's PRU bit against whether
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the fault happened in user mode or privileged mode. */
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static struct expevt_lookup expevt_lookup_table = {
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@ -164,12 +116,10 @@ static struct expevt_lookup expevt_lookup_table = {
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general fault handling in fault.c which deals with mapping file-backed
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pages, stack growth, segmentation faults, swapping etc etc)
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*/
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asmlinkage int do_fast_page_fault(unsigned long long ssr_md,
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unsigned long long expevt,
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unsigned long address)
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asmlinkage int __kprobes
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do_fast_page_fault(unsigned long long ssr_md, unsigned long long expevt,
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unsigned long address)
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{
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struct task_struct *tsk;
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struct mm_struct *mm;
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unsigned long long protection_flags;
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unsigned long long index;
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unsigned long long expevt4;
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@ -194,32 +144,5 @@ asmlinkage int do_fast_page_fault(unsigned long long ssr_md,
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if (expevt_lookup_table.is_text_access[index])
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set_thread_fault_code(FAULT_CODE_ITLB);
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/* SIM
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* Note this is now called with interrupts still disabled
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* This is to cope with being called for a missing IO port
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* address with interrupts disabled. This should be fixed as
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* soon as we have a better 'fast path' miss handler.
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*
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* Plus take care how you try and debug this stuff.
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* For example, writing debug data to a port which you
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* have just faulted on is not going to work.
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*/
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tsk = current;
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mm = tsk->mm;
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if (is_vmalloc_addr((void *)address)) {
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if (ssr_md)
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/*
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* Process-contexts can never have this address
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* range mapped
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*/
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if (handle_vmalloc_fault(mm, protection_flags, address) == 0)
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return 0;
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} else if (!in_interrupt() && mm) {
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if (handle_tlbmiss(mm, protection_flags, address) == 0)
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return 0;
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}
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return 1;
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return handle_tlbmiss(protection_flags, address);
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}
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