sh: pmd rework.
Remove extra bits from the pmd structure and store a kernel logical address rather than a physical address. This allows it to be directly dereferenced. Another piece of wierdness inherited from x86. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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@ -46,6 +46,45 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
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mm = tsk->mm;
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si_code = SEGV_MAPERR;
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if (unlikely(address >= TASK_SIZE)) {
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/*
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* Synchronize this task's top level page-table
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* with the 'reference' page table.
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*
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* Do _not_ use "tsk" here. We might be inside
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* an interrupt in the middle of a task switch..
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*/
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int offset = pgd_index(address);
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pgd_t *pgd, *pgd_k;
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pud_t *pud, *pud_k;
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pmd_t *pmd, *pmd_k;
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pgd = get_TTB() + offset;
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pgd_k = swapper_pg_dir + offset;
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/* This will never happen with the folded page table. */
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if (!pgd_present(*pgd)) {
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if (!pgd_present(*pgd_k))
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goto bad_area_nosemaphore;
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set_pgd(pgd, *pgd_k);
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return;
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}
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pud = pud_offset(pgd, address);
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pud_k = pud_offset(pgd_k, address);
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if (pud_present(*pud) || !pud_present(*pud_k))
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goto bad_area_nosemaphore;
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set_pud(pud, *pud_k);
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pmd = pmd_offset(pud, address);
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pmd_k = pmd_offset(pud_k, address);
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if (pmd_present(*pmd) || !pmd_present(*pmd_k))
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goto bad_area_nosemaphore;
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set_pmd(pmd, *pmd_k);
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return;
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}
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/*
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* If we're in an interrupt or have no user
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* context, we must not take the fault..
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@ -109,6 +148,7 @@ survive:
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bad_area:
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up_read(&mm->mmap_sem);
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bad_area_nosemaphore:
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if (user_mode(regs)) {
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info.si_signo = SIGSEGV;
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info.si_errno = 0;
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@ -84,30 +84,22 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
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pmd_t *pmd;
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pte_t *pte;
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pgd = swapper_pg_dir + pgd_index(addr);
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pgd = pgd_offset_k(addr);
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if (pgd_none(*pgd)) {
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pgd_ERROR(*pgd);
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return;
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}
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pud = pud_offset(pgd, addr);
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if (pud_none(*pud)) {
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pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC);
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set_pud(pud, __pud(__pa(pmd) | _PAGE_TABLE));
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if (pmd != pmd_offset(pud, 0)) {
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pud_ERROR(*pud);
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return;
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}
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pud = pud_alloc(NULL, pgd, addr);
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if (unlikely(!pud)) {
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pud_ERROR(*pud);
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return;
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}
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pmd = pmd_offset(pud, addr);
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if (pmd_none(*pmd)) {
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pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
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set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
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if (pte != pte_offset_kernel(pmd, 0)) {
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pmd_ERROR(*pmd);
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return;
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}
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pmd = pmd_alloc(NULL, pud, addr);
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if (unlikely(!pmd)) {
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pmd_ERROR(*pmd);
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return;
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}
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pte = pte_offset_kernel(pmd, addr);
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@ -1,13 +1,16 @@
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#ifndef __ASM_SH_PGALLOC_H
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#define __ASM_SH_PGALLOC_H
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#define pmd_populate_kernel(mm, pmd, pte) \
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set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte)))
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static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
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pte_t *pte)
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{
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set_pmd(pmd, __pmd((unsigned long)pte));
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}
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static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
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struct page *pte)
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{
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set_pmd(pmd, __pmd(_PAGE_TABLE + page_to_phys(pte)));
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set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
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}
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/*
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@ -15,7 +18,16 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
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*/
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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return (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
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pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
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if (pgd) {
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memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
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memcpy(pgd + USER_PTRS_PER_PGD,
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swapper_pg_dir + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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}
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return pgd;
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}
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static inline void pgd_free(pgd_t *pgd)
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@ -203,26 +203,18 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
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#ifndef __ASSEMBLY__
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#if defined(CONFIG_X2TLB) /* SH-X2 TLB */
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#define _PAGE_TABLE \
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(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY | \
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_PAGE_EXT(_PAGE_EXT_USER_READ | _PAGE_EXT_USER_WRITE))
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#define _KERNPG_TABLE \
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(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY | \
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_PAGE_EXT(_PAGE_EXT_KERN_READ | _PAGE_EXT_KERN_WRITE))
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#define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE | \
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_PAGE_ACCESSED | _PAGE_FLAGS_HARD)
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#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
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_PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_USER_READ | \
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_PAGE_EXT_USER_WRITE))
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_PAGE_EXT_USER_WRITE))
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#define PAGE_EXECREAD __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
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_PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_USER_EXEC | \
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_PAGE_EXT_USER_READ))
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_PAGE_EXT_USER_READ))
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#define PAGE_COPY PAGE_EXECREAD
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@ -237,14 +229,14 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
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#define PAGE_RWX __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
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_PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_USER_WRITE | \
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_PAGE_EXT_USER_READ | \
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_PAGE_EXT_USER_READ | \
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_PAGE_EXT_USER_EXEC))
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#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
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_PAGE_DIRTY | _PAGE_ACCESSED | \
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_PAGE_HW_SHARED | _PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_KERN_READ | \
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_PAGE_EXT_KERN_WRITE | \
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_PAGE_EXT_KERN_WRITE | \
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_PAGE_EXT_KERN_EXEC))
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#define PAGE_KERNEL_NOCACHE \
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@ -252,30 +244,25 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
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_PAGE_ACCESSED | _PAGE_HW_SHARED | \
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_PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_KERN_READ | \
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_PAGE_EXT_KERN_WRITE | \
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_PAGE_EXT_KERN_WRITE | \
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_PAGE_EXT_KERN_EXEC))
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#define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
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_PAGE_DIRTY | _PAGE_ACCESSED | \
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_PAGE_HW_SHARED | _PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_KERN_READ | \
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_PAGE_EXT_KERN_EXEC))
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_PAGE_EXT_KERN_EXEC))
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#define PAGE_KERNEL_PCC(slot, type) \
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__pgprot(_PAGE_PRESENT | _PAGE_DIRTY | \
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_PAGE_ACCESSED | _PAGE_FLAGS_HARD | \
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_PAGE_EXT(_PAGE_EXT_KERN_READ | \
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_PAGE_EXT_KERN_WRITE | \
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_PAGE_EXT_KERN_WRITE | \
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_PAGE_EXT_KERN_EXEC) \
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(slot ? _PAGE_PCC_AREA5 : _PAGE_PCC_AREA6) | \
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(type))
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#elif defined(CONFIG_MMU) /* SH-X TLB */
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#define _PAGE_TABLE \
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(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
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#define _KERNPG_TABLE \
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(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
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#define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE | \
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_PAGE_ACCESSED | _PAGE_FLAGS_HARD)
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@ -390,9 +377,9 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
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#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
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#define pmd_none(x) (!pmd_val(x))
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#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
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#define pmd_present(x) (pmd_val(x))
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#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
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#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
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#define pmd_bad(x) (pmd_val(x) & ~PAGE_MASK)
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#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
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#define pte_page(x) phys_to_page(pte_val(x)&PTE_PHYS_MASK)
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@ -477,11 +464,8 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
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return pte;
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}
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#define pmd_page_vaddr(pmd) \
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((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
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#define pmd_page(pmd) \
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(phys_to_page(pmd_val(pmd)))
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#define pmd_page_vaddr(pmd) pmd_val(pmd)
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#define pmd_page(pmd) (virt_to_page(pmd_val(pmd)))
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/* to find an entry in a page-table-directory. */
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#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
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