From 392c3822a6fc247c0708c9e52c0818d1fbc9d7d7 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Mon, 14 May 2012 17:24:21 +0900 Subject: 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 --- arch/sh/mm/tlbex_64.c | 107 +++++++------------------------------------------- 1 file changed, 15 insertions(+), 92 deletions(-) (limited to 'arch/sh/mm') diff --git a/arch/sh/mm/tlbex_64.c b/arch/sh/mm/tlbex_64.c index 59cb058217a0..24dd4ab33dec 100644 --- a/arch/sh/mm/tlbex_64.c +++ b/arch/sh/mm/tlbex_64.c @@ -33,76 +33,32 @@ #include #include #include +#include #include #include #include #include #include -static int handle_vmalloc_fault(struct mm_struct *mm, - unsigned long protection_flags, - unsigned long address) -{ - pgd_t *dir; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - pte_t entry; - - dir = pgd_offset_k(address); - - pud = pud_offset(dir, 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 (pte_none(entry) || !pte_present(entry)) - return 1; - if ((pte_val(entry) & protection_flags) != protection_flags) - return 1; - - update_mmu_cache(NULL, address, pte); - - return 0; -} - -static int handle_tlbmiss(struct mm_struct *mm, - unsigned long long protection_flags, +static int handle_tlbmiss(unsigned long long protection_flags, unsigned long address) { - pgd_t *dir; + pgd_t *pgd; 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 1; + if (is_vmalloc_addr((void *)address)) { + pgd = pgd_offset_k(address); + } else { + if (unlikely(address >= TASK_SIZE || !current->mm)) + return 1; - dir = pgd_offset(mm, address); - if (pgd_none(*dir) || !pgd_present(*dir)) - return 1; - if (!pgd_present(*dir)) - return 1; + pgd = pgd_offset(current->mm, address); + } - pud = pud_offset(dir, address); + pud = pud_offset(pgd, address); if (pud_none(*pud) || !pud_present(*pud)) return 1; @@ -112,7 +68,6 @@ static int handle_tlbmiss(struct mm_struct *mm, pte = pte_offset_kernel(pmd, address); entry = *pte; - if (pte_none(entry) || !pte_present(entry)) return 1; @@ -146,9 +101,6 @@ struct expevt_lookup { #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 = { @@ -164,12 +116,10 @@ static struct expevt_lookup expevt_lookup_table = { 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) +asmlinkage int __kprobes +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 protection_flags; unsigned long long index; unsigned long long expevt4; @@ -194,32 +144,5 @@ asmlinkage int do_fast_page_fault(unsigned long long ssr_md, if (expevt_lookup_table.is_text_access[index]) set_thread_fault_code(FAULT_CODE_ITLB); - /* 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 (is_vmalloc_addr((void *)address)) { - if (ssr_md) - /* - * Process-contexts can never have this address - * range mapped - */ - if (handle_vmalloc_fault(mm, protection_flags, address) == 0) - return 0; - } else if (!in_interrupt() && mm) { - if (handle_tlbmiss(mm, protection_flags, address) == 0) - return 0; - } - - return 1; + return handle_tlbmiss(protection_flags, address); } -- cgit v1.2.3