diff options
Diffstat (limited to 'arch/mips/mm/highmem.c')
| -rw-r--r-- | arch/mips/mm/highmem.c | 133 |
1 files changed, 6 insertions, 127 deletions
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c index da815d295239..57e2f08f00d0 100644 --- a/arch/mips/mm/highmem.c +++ b/arch/mips/mm/highmem.c @@ -1,138 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/compiler.h> -#include <linux/module.h> +#include <linux/init.h> +#include <linux/export.h> #include <linux/highmem.h> #include <linux/sched.h> #include <linux/smp.h> #include <asm/fixmap.h> #include <asm/tlbflush.h> -static pte_t *kmap_pte; - unsigned long highstart_pfn, highend_pfn; -void *kmap(struct page *page) -{ - void *addr; - - might_sleep(); - if (!PageHighMem(page)) - return page_address(page); - addr = kmap_high(page); - flush_tlb_one((unsigned long)addr); - - return addr; -} -EXPORT_SYMBOL(kmap); - -void kunmap(struct page *page) -{ - BUG_ON(in_interrupt()); - if (!PageHighMem(page)) - return; - kunmap_high(page); -} -EXPORT_SYMBOL(kunmap); - -/* - * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because - * no global lock is needed and because the kmap code must perform a global TLB - * invalidation when the kmap pool wraps. - * - * However when holding an atomic kmap is is not legal to sleep, so atomic - * kmaps are appropriate for short, tight code paths only. - */ - -void *kmap_atomic(struct page *page) +void kmap_flush_tlb(unsigned long addr) { - unsigned long vaddr; - int idx, type; - - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - pagefault_disable(); - if (!PageHighMem(page)) - return page_address(page); - - type = kmap_atomic_idx_push(); - idx = type + KM_TYPE_NR*smp_processor_id(); - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); -#ifdef CONFIG_DEBUG_HIGHMEM - BUG_ON(!pte_none(*(kmap_pte - idx))); -#endif - set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL)); - local_flush_tlb_one((unsigned long)vaddr); - - return (void*) vaddr; -} -EXPORT_SYMBOL(kmap_atomic); - -void __kunmap_atomic(void *kvaddr) -{ - unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; - int type __maybe_unused; - - if (vaddr < FIXADDR_START) { // FIXME - pagefault_enable(); - return; - } - - type = kmap_atomic_idx(); -#ifdef CONFIG_DEBUG_HIGHMEM - { - int idx = type + KM_TYPE_NR * smp_processor_id(); - - BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); - - /* - * force other mappings to Oops if they'll try to access - * this pte without first remap it - */ - pte_clear(&init_mm, vaddr, kmap_pte-idx); - local_flush_tlb_one(vaddr); - } -#endif - kmap_atomic_idx_pop(); - pagefault_enable(); -} -EXPORT_SYMBOL(__kunmap_atomic); - -/* - * This is the same as kmap_atomic() but can map memory that doesn't - * have a struct page associated with it. - */ -void *kmap_atomic_pfn(unsigned long pfn) -{ - unsigned long vaddr; - int idx, type; - - pagefault_disable(); - - type = kmap_atomic_idx_push(); - idx = type + KM_TYPE_NR*smp_processor_id(); - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); - set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL)); - flush_tlb_one(vaddr); - - return (void*) vaddr; -} - -struct page *kmap_atomic_to_page(void *ptr) -{ - unsigned long idx, vaddr = (unsigned long)ptr; - pte_t *pte; - - if (vaddr < FIXADDR_START) - return virt_to_page(ptr); - - idx = virt_to_fix(vaddr); - pte = kmap_pte - (idx - FIX_KMAP_BEGIN); - return pte_page(*pte); -} - -void __init kmap_init(void) -{ - unsigned long kmap_vstart; - - /* cache the first kmap pte */ - kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); - kmap_pte = kmap_get_fixmap_pte(kmap_vstart); + flush_tlb_one(addr); } +EXPORT_SYMBOL(kmap_flush_tlb); |
