forked from mirrors/linux
highmem: Provide generic variant of kmap_atomic*
The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations. Provide a generic variant for that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20201103095857.175939340@linutronix.de
This commit is contained in:
Thomas Gleixner
parent
4f8b96cd47
commit
298fa1ad55
3 changed files with 211 additions and 18 deletions
|
|
@ -31,9 +31,16 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
|
|||
|
||||
#include <asm/kmap_types.h>
|
||||
|
||||
/*
|
||||
* Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
|
||||
*/
|
||||
#ifdef CONFIG_KMAP_LOCAL
|
||||
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
|
||||
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
|
||||
void kunmap_local_indexed(void *vaddr);
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_HIGHMEM
|
||||
extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
|
||||
extern void kunmap_atomic_high(void *kvaddr);
|
||||
#include <asm/highmem.h>
|
||||
|
||||
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
|
||||
|
|
@ -81,6 +88,11 @@ static inline void kunmap(struct page *page)
|
|||
* be used in IRQ contexts, so in some (very limited) cases we need
|
||||
* it.
|
||||
*/
|
||||
|
||||
#ifndef CONFIG_KMAP_LOCAL
|
||||
void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
|
||||
void kunmap_atomic_high(void *kvaddr);
|
||||
|
||||
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
|
||||
{
|
||||
preempt_disable();
|
||||
|
|
@ -89,7 +101,38 @@ static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
|
|||
return page_address(page);
|
||||
return kmap_atomic_high_prot(page, prot);
|
||||
}
|
||||
#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
|
||||
|
||||
static inline void __kunmap_atomic(void *vaddr)
|
||||
{
|
||||
kunmap_atomic_high(vaddr);
|
||||
}
|
||||
#else /* !CONFIG_KMAP_LOCAL */
|
||||
|
||||
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
|
||||
{
|
||||
preempt_disable();
|
||||
pagefault_disable();
|
||||
return __kmap_local_page_prot(page, prot);
|
||||
}
|
||||
|
||||
static inline void *kmap_atomic_pfn(unsigned long pfn)
|
||||
{
|
||||
preempt_disable();
|
||||
pagefault_disable();
|
||||
return __kmap_local_pfn_prot(pfn, kmap_prot);
|
||||
}
|
||||
|
||||
static inline void __kunmap_atomic(void *addr)
|
||||
{
|
||||
kunmap_local_indexed(addr);
|
||||
}
|
||||
|
||||
#endif /* CONFIG_KMAP_LOCAL */
|
||||
|
||||
static inline void *kmap_atomic(struct page *page)
|
||||
{
|
||||
return kmap_atomic_prot(page, kmap_prot);
|
||||
}
|
||||
|
||||
/* declarations for linux/mm/highmem.c */
|
||||
unsigned int nr_free_highpages(void);
|
||||
|
|
@ -147,25 +190,33 @@ static inline void *kmap_atomic(struct page *page)
|
|||
pagefault_disable();
|
||||
return page_address(page);
|
||||
}
|
||||
#define kmap_atomic_prot(page, prot) kmap_atomic(page)
|
||||
|
||||
static inline void kunmap_atomic_high(void *addr)
|
||||
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
|
||||
{
|
||||
return kmap_atomic(page);
|
||||
}
|
||||
|
||||
static inline void *kmap_atomic_pfn(unsigned long pfn)
|
||||
{
|
||||
return kmap_atomic(pfn_to_page(pfn));
|
||||
}
|
||||
|
||||
static inline void __kunmap_atomic(void *addr)
|
||||
{
|
||||
/*
|
||||
* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
|
||||
* handles re-enabling faults + preemption
|
||||
* handles re-enabling faults and preemption
|
||||
*/
|
||||
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
|
||||
kunmap_flush_on_unmap(addr);
|
||||
#endif
|
||||
}
|
||||
|
||||
#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
|
||||
|
||||
#define kmap_flush_unused() do {} while(0)
|
||||
|
||||
#endif /* CONFIG_HIGHMEM */
|
||||
|
||||
#if !defined(CONFIG_KMAP_LOCAL)
|
||||
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
|
||||
|
||||
DECLARE_PER_CPU(int, __kmap_atomic_idx);
|
||||
|
|
@ -196,22 +247,21 @@ static inline void kmap_atomic_idx_pop(void)
|
|||
__this_cpu_dec(__kmap_atomic_idx);
|
||||
#endif
|
||||
}
|
||||
|
||||
#endif
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
|
||||
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
|
||||
*/
|
||||
#define kunmap_atomic(addr) \
|
||||
do { \
|
||||
BUILD_BUG_ON(__same_type((addr), struct page *)); \
|
||||
kunmap_atomic_high(addr); \
|
||||
pagefault_enable(); \
|
||||
preempt_enable(); \
|
||||
#define kunmap_atomic(__addr) \
|
||||
do { \
|
||||
BUILD_BUG_ON(__same_type((__addr), struct page *)); \
|
||||
__kunmap_atomic(__addr); \
|
||||
pagefault_enable(); \
|
||||
preempt_enable(); \
|
||||
} while (0)
|
||||
|
||||
|
||||
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
|
||||
#ifndef clear_user_highpage
|
||||
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
|
||||
|
|
|
|||
|
|
@ -872,4 +872,7 @@ config ARCH_HAS_HUGEPD
|
|||
config MAPPING_DIRTY_HELPERS
|
||||
bool
|
||||
|
||||
config KMAP_LOCAL
|
||||
bool
|
||||
|
||||
endmenu
|
||||
|
|
|
|||
144
mm/highmem.c
144
mm/highmem.c
|
|
@ -31,9 +31,11 @@
|
|||
#include <asm/tlbflush.h>
|
||||
#include <linux/vmalloc.h>
|
||||
|
||||
#ifndef CONFIG_KMAP_LOCAL
|
||||
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
|
||||
DEFINE_PER_CPU(int, __kmap_atomic_idx);
|
||||
#endif
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Virtual_count is not a pure "count".
|
||||
|
|
@ -365,9 +367,147 @@ void kunmap_high(struct page *page)
|
|||
if (need_wakeup)
|
||||
wake_up(pkmap_map_wait);
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(kunmap_high);
|
||||
#endif /* CONFIG_HIGHMEM */
|
||||
#endif /* CONFIG_HIGHMEM */
|
||||
|
||||
#ifdef CONFIG_KMAP_LOCAL
|
||||
|
||||
#include <asm/kmap_size.h>
|
||||
|
||||
static DEFINE_PER_CPU(int, __kmap_local_idx);
|
||||
|
||||
static inline int kmap_local_idx_push(void)
|
||||
{
|
||||
int idx = __this_cpu_inc_return(__kmap_local_idx) - 1;
|
||||
|
||||
WARN_ON_ONCE(in_irq() && !irqs_disabled());
|
||||
BUG_ON(idx >= KM_MAX_IDX);
|
||||
return idx;
|
||||
}
|
||||
|
||||
static inline int kmap_local_idx(void)
|
||||
{
|
||||
return __this_cpu_read(__kmap_local_idx) - 1;
|
||||
}
|
||||
|
||||
static inline void kmap_local_idx_pop(void)
|
||||
{
|
||||
int idx = __this_cpu_dec_return(__kmap_local_idx);
|
||||
|
||||
BUG_ON(idx < 0);
|
||||
}
|
||||
|
||||
#ifndef arch_kmap_local_post_map
|
||||
# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0)
|
||||
#endif
|
||||
#ifndef arch_kmap_local_pre_unmap
|
||||
# define arch_kmap_local_pre_unmap(vaddr) do { } while (0)
|
||||
#endif
|
||||
|
||||
#ifndef arch_kmap_local_post_unmap
|
||||
# define arch_kmap_local_post_unmap(vaddr) do { } while (0)
|
||||
#endif
|
||||
|
||||
#ifndef arch_kmap_local_map_idx
|
||||
#define arch_kmap_local_map_idx(idx, pfn) kmap_local_calc_idx(idx)
|
||||
#endif
|
||||
|
||||
#ifndef arch_kmap_local_unmap_idx
|
||||
#define arch_kmap_local_unmap_idx(idx, vaddr) kmap_local_calc_idx(idx)
|
||||
#endif
|
||||
|
||||
#ifndef arch_kmap_local_high_get
|
||||
static inline void *arch_kmap_local_high_get(struct page *page)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
#endif
|
||||
|
||||
/* Unmap a local mapping which was obtained by kmap_high_get() */
|
||||
static inline void kmap_high_unmap_local(unsigned long vaddr)
|
||||
{
|
||||
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
|
||||
if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP))
|
||||
kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
|
||||
#endif
|
||||
}
|
||||
|
||||
static inline int kmap_local_calc_idx(int idx)
|
||||
{
|
||||
return idx + KM_MAX_IDX * smp_processor_id();
|
||||
}
|
||||
|
||||
static pte_t *__kmap_pte;
|
||||
|
||||
static pte_t *kmap_get_pte(void)
|
||||
{
|
||||
if (!__kmap_pte)
|
||||
__kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
|
||||
return __kmap_pte;
|
||||
}
|
||||
|
||||
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
|
||||
{
|
||||
pte_t pteval, *kmap_pte = kmap_get_pte();
|
||||
unsigned long vaddr;
|
||||
int idx;
|
||||
|
||||
preempt_disable();
|
||||
idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn);
|
||||
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
|
||||
BUG_ON(!pte_none(*(kmap_pte - idx)));
|
||||
pteval = pfn_pte(pfn, prot);
|
||||
set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval);
|
||||
arch_kmap_local_post_map(vaddr, pteval);
|
||||
preempt_enable();
|
||||
|
||||
return (void *)vaddr;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(__kmap_local_pfn_prot);
|
||||
|
||||
void *__kmap_local_page_prot(struct page *page, pgprot_t prot)
|
||||
{
|
||||
void *kmap;
|
||||
|
||||
if (!PageHighMem(page))
|
||||
return page_address(page);
|
||||
|
||||
/* Try kmap_high_get() if architecture has it enabled */
|
||||
kmap = arch_kmap_local_high_get(page);
|
||||
if (kmap)
|
||||
return kmap;
|
||||
|
||||
return __kmap_local_pfn_prot(page_to_pfn(page), prot);
|
||||
}
|
||||
EXPORT_SYMBOL(__kmap_local_page_prot);
|
||||
|
||||
void kunmap_local_indexed(void *vaddr)
|
||||
{
|
||||
unsigned long addr = (unsigned long) vaddr & PAGE_MASK;
|
||||
pte_t *kmap_pte = kmap_get_pte();
|
||||
int idx;
|
||||
|
||||
if (addr < __fix_to_virt(FIX_KMAP_END) ||
|
||||
addr > __fix_to_virt(FIX_KMAP_BEGIN)) {
|
||||
WARN_ON_ONCE(addr < PAGE_OFFSET);
|
||||
|
||||
/* Handle mappings which were obtained by kmap_high_get() */
|
||||
kmap_high_unmap_local(addr);
|
||||
return;
|
||||
}
|
||||
|
||||
preempt_disable();
|
||||
idx = arch_kmap_local_unmap_idx(kmap_local_idx(), addr);
|
||||
WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
|
||||
|
||||
arch_kmap_local_pre_unmap(addr);
|
||||
pte_clear(&init_mm, addr, kmap_pte - idx);
|
||||
arch_kmap_local_post_unmap(addr);
|
||||
kmap_local_idx_pop();
|
||||
preempt_enable();
|
||||
}
|
||||
EXPORT_SYMBOL(kunmap_local_indexed);
|
||||
#endif
|
||||
|
||||
#if defined(HASHED_PAGE_VIRTUAL)
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue