aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mm/highmem.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mm/highmem.c')
-rw-r--r--arch/arm/mm/highmem.c151
1 files changed, 40 insertions, 111 deletions
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 1fbdb55bfd1..45aeaaca905 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -18,6 +18,21 @@
#include <asm/tlbflush.h>
#include "mm.h"
+pte_t *fixmap_page_table;
+
+static inline void set_fixmap_pte(int idx, pte_t pte)
+{
+ unsigned long vaddr = __fix_to_virt(idx);
+ set_pte_ext(fixmap_page_table + idx, pte, 0);
+ local_flush_tlb_kernel_page(vaddr);
+}
+
+static inline pte_t get_fixmap_pte(unsigned long vaddr)
+{
+ unsigned long idx = __virt_to_fix(vaddr);
+ return *(fixmap_page_table + idx);
+}
+
void *kmap(struct page *page)
{
might_sleep();
@@ -36,18 +51,17 @@ void kunmap(struct page *page)
}
EXPORT_SYMBOL(kunmap);
-void *kmap_atomic(struct page *page, enum km_type type)
+void *kmap_atomic(struct page *page)
{
unsigned int idx;
unsigned long vaddr;
void *kmap;
+ int type;
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
- debug_kmap_atomic(type);
-
#ifdef CONFIG_DEBUG_HIGHMEM
/*
* There is no cache coherency issue when non VIVT, so force the
@@ -61,64 +75,68 @@ void *kmap_atomic(struct page *page, enum km_type type)
if (kmap)
return kmap;
+ type = kmap_atomic_idx_push();
+
idx = type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ vaddr = __fix_to_virt(idx);
#ifdef CONFIG_DEBUG_HIGHMEM
/*
* With debugging enabled, kunmap_atomic forces that entry to 0.
* Make sure it was indeed properly unmapped.
*/
- BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
+ BUG_ON(!pte_none(*(fixmap_page_table + idx)));
#endif
- set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0);
/*
* When debugging is off, kunmap_atomic leaves the previous mapping
- * in place, so this TLB flush ensures the TLB is updated with the
- * new mapping.
+ * in place, so the contained TLB flush ensures the TLB is updated
+ * with the new mapping.
*/
- local_flush_tlb_kernel_page(vaddr);
+ set_fixmap_pte(idx, mk_pte(page, kmap_prot));
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic);
-void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type)
+void __kunmap_atomic(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- unsigned int idx = type + KM_TYPE_NR * smp_processor_id();
+ int idx, type;
if (kvaddr >= (void *)FIXADDR_START) {
+ type = kmap_atomic_idx();
+ idx = type + KM_TYPE_NR * smp_processor_id();
+
if (cache_is_vivt())
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
- set_pte_ext(TOP_PTE(vaddr), __pte(0), 0);
- local_flush_tlb_kernel_page(vaddr);
+ BUG_ON(vaddr != __fix_to_virt(idx));
+ set_fixmap_pte(idx, __pte(0));
#else
(void) idx; /* to kill a warning */
#endif
+ kmap_atomic_idx_pop();
} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
/* this address was obtained through kmap_high_get() */
kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
}
pagefault_enable();
}
-EXPORT_SYMBOL(kunmap_atomic_notypecheck);
+EXPORT_SYMBOL(__kunmap_atomic);
-void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+void *kmap_atomic_pfn(unsigned long pfn)
{
- unsigned int idx;
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);
+ vaddr = __fix_to_virt(idx);
#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
+ BUG_ON(!pte_none(*(fixmap_page_table + idx)));
#endif
- set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0);
- local_flush_tlb_kernel_page(vaddr);
+ set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
return (void *)vaddr;
}
@@ -126,98 +144,9 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
struct page *kmap_atomic_to_page(const void *ptr)
{
unsigned long vaddr = (unsigned long)ptr;
- pte_t *pte;
if (vaddr < FIXADDR_START)
return virt_to_page(ptr);
- pte = TOP_PTE(vaddr);
- return pte_page(*pte);
-}
-
-#ifdef CONFIG_CPU_CACHE_VIPT
-
-#include <linux/percpu.h>
-
-/*
- * The VIVT cache of a highmem page is always flushed before the page
- * is unmapped. Hence unmapped highmem pages need no cache maintenance
- * in that case.
- *
- * However unmapped pages may still be cached with a VIPT cache, and
- * it is not possible to perform cache maintenance on them using physical
- * addresses unfortunately. So we have no choice but to set up a temporary
- * virtual mapping for that purpose.
- *
- * Yet this VIPT cache maintenance may be triggered from DMA support
- * functions which are possibly called from interrupt context. As we don't
- * want to keep interrupt disabled all the time when such maintenance is
- * taking place, we therefore allow for some reentrancy by preserving and
- * restoring the previous fixmap entry before the interrupted context is
- * resumed. If the reentrancy depth is 0 then there is no need to restore
- * the previous fixmap, and leaving the current one in place allow it to
- * be reused the next time without a TLB flush (common with DMA).
- */
-
-static DEFINE_PER_CPU(int, kmap_high_l1_vipt_depth);
-
-void *kmap_high_l1_vipt(struct page *page, pte_t *saved_pte)
-{
- unsigned int idx, cpu;
- int *depth;
- unsigned long vaddr, flags;
- pte_t pte, *ptep;
-
- if (!in_interrupt())
- preempt_disable();
-
- cpu = smp_processor_id();
- depth = &per_cpu(kmap_high_l1_vipt_depth, cpu);
-
- idx = KM_L1_CACHE + KM_TYPE_NR * cpu;
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- ptep = TOP_PTE(vaddr);
- pte = mk_pte(page, kmap_prot);
-
- raw_local_irq_save(flags);
- (*depth)++;
- if (pte_val(*ptep) == pte_val(pte)) {
- *saved_pte = pte;
- } else {
- *saved_pte = *ptep;
- set_pte_ext(ptep, pte, 0);
- local_flush_tlb_kernel_page(vaddr);
- }
- raw_local_irq_restore(flags);
-
- return (void *)vaddr;
-}
-
-void kunmap_high_l1_vipt(struct page *page, pte_t saved_pte)
-{
- unsigned int idx, cpu = smp_processor_id();
- int *depth = &per_cpu(kmap_high_l1_vipt_depth, cpu);
- unsigned long vaddr, flags;
- pte_t pte, *ptep;
-
- idx = KM_L1_CACHE + KM_TYPE_NR * cpu;
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- ptep = TOP_PTE(vaddr);
- pte = mk_pte(page, kmap_prot);
-
- BUG_ON(pte_val(*ptep) != pte_val(pte));
- BUG_ON(*depth <= 0);
-
- raw_local_irq_save(flags);
- (*depth)--;
- if (*depth != 0 && pte_val(pte) != pte_val(saved_pte)) {
- set_pte_ext(ptep, saved_pte, 0);
- local_flush_tlb_kernel_page(vaddr);
- }
- raw_local_irq_restore(flags);
-
- if (!in_interrupt())
- preempt_enable();
+ return pte_page(get_fixmap_pte(vaddr));
}
-
-#endif /* CONFIG_CPU_CACHE_VIPT */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 09:05:48 +0000