From 336e2136e1353db8e9e731c27381ee0735656a8a Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Thu, 5 Mar 2015 17:06:31 +0530 Subject: [PATCH] ARC: mm: preps ahead of HIGHMEM support Before we plug in highmem support, some of code needs to be ready for it - copy_user_highpage() needs to be using the kmap_atomic API - mk_pte() can't assume page_address() - do_page_fault() can't assume VMALLOC_END is end of kernel vaddr space Signed-off-by: Alexey Brodkin Signed-off-by: Vineet Gupta --- arch/arc/include/asm/pgtable.h | 9 +-------- arch/arc/mm/cache.c | 16 +++++++++++----- arch/arc/mm/fault.c | 13 ++++++++++--- 3 files changed, 22 insertions(+), 16 deletions(-) diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h index f7c7273cd537..bd771351a1d1 100644 --- a/arch/arc/include/asm/pgtable.h +++ b/arch/arc/include/asm/pgtable.h @@ -270,13 +270,7 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) (unsigned long)(((pte_val(x) - CONFIG_LINUX_LINK_BASE) >> \ PAGE_SHIFT))) -#define mk_pte(page, pgprot) \ -({ \ - pte_t pte; \ - pte_val(pte) = __pa(page_address(page)) + pgprot_val(pgprot); \ - pte; \ -}) - +#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) #define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))) #define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) @@ -360,7 +354,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #define pgd_offset_fast(mm, addr) pgd_offset(mm, addr) #endif -extern void paging_init(void); extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE); void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep); diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c index ae3b772ecc4d..521fb2bf90bd 100644 --- a/arch/arc/mm/cache.c +++ b/arch/arc/mm/cache.c @@ -806,8 +806,8 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page, void copy_user_highpage(struct page *to, struct page *from, unsigned long u_vaddr, struct vm_area_struct *vma) { - unsigned long kfrom = (unsigned long)page_address(from); - unsigned long kto = (unsigned long)page_address(to); + void *kfrom = kmap_atomic(from); + void *kto = kmap_atomic(to); int clean_src_k_mappings = 0; /* @@ -817,13 +817,16 @@ void copy_user_highpage(struct page *to, struct page *from, * * Note that while @u_vaddr refers to DST page's userspace vaddr, it is * equally valid for SRC page as well + * + * For !VIPT cache, all of this gets compiled out as + * addr_not_cache_congruent() is 0 */ if (page_mapped(from) && addr_not_cache_congruent(kfrom, u_vaddr)) { - __flush_dcache_page(kfrom, u_vaddr); + __flush_dcache_page((unsigned long)kfrom, u_vaddr); clean_src_k_mappings = 1; } - copy_page((void *)kto, (void *)kfrom); + copy_page(kto, kfrom); /* * Mark DST page K-mapping as dirty for a later finalization by @@ -840,11 +843,14 @@ void copy_user_highpage(struct page *to, struct page *from, * sync the kernel mapping back to physical page */ if (clean_src_k_mappings) { - __flush_dcache_page(kfrom, kfrom); + __flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom); set_bit(PG_dc_clean, &from->flags); } else { clear_bit(PG_dc_clean, &from->flags); } + + kunmap_atomic(kto); + kunmap_atomic(kfrom); } void clear_user_page(void *to, unsigned long u_vaddr, struct page *page) diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c index d948e4e9d89c..af63f4a13e60 100644 --- a/arch/arc/mm/fault.c +++ b/arch/arc/mm/fault.c @@ -18,7 +18,14 @@ #include #include -static int handle_vmalloc_fault(unsigned long address) +/* + * kernel virtual address is required to implement vmalloc/pkmap/fixmap + * Refer to asm/processor.h for System Memory Map + * + * It simply copies the PMD entry (pointer to 2nd level page table or hugepage) + * from swapper pgdir to task pgdir. The 2nd level table/page is thus shared + */ +noinline static int handle_kernel_vaddr_fault(unsigned long address) { /* * Synchronize this task's top level page-table @@ -72,8 +79,8 @@ void do_page_fault(unsigned long address, struct pt_regs *regs) * only copy the information from the master page table, * nothing more. */ - if (address >= VMALLOC_START && address <= VMALLOC_END) { - ret = handle_vmalloc_fault(address); + if (address >= VMALLOC_START) { + ret = handle_kernel_vaddr_fault(address); if (unlikely(ret)) goto bad_area_nosemaphore; else -- 2.20.1