#include <linux/init.h>
#include <linux/hash.h>
#include <linux/highmem.h>
-#include <linux/blktrace_api.h>
+#include <linux/kgdb.h>
#include <asm/tlbflush.h>
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+DEFINE_PER_CPU(int, __kmap_atomic_idx);
+#endif
+
/*
* Virtual_count is not a pure "count".
* 0 means that it is not mapped, and has not been mapped
#ifdef CONFIG_HIGHMEM
unsigned long totalhigh_pages __read_mostly;
+EXPORT_SYMBOL(totalhigh_pages);
+
+
+EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
unsigned int nr_free_highpages (void)
{
pg_data_t *pgdat;
unsigned int pages = 0;
- for_each_online_pgdat(pgdat)
+ for_each_online_pgdat(pgdat) {
pages += zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
NR_FREE_PAGES);
+ if (zone_movable_is_highmem())
+ pages += zone_page_state(
+ &pgdat->node_zones[ZONE_MOVABLE],
+ NR_FREE_PAGES);
+ }
return pages;
}
static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
+/*
+ * Most architectures have no use for kmap_high_get(), so let's abstract
+ * the disabling of IRQ out of the locking in that case to save on a
+ * potential useless overhead.
+ */
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+#define lock_kmap() spin_lock_irq(&kmap_lock)
+#define unlock_kmap() spin_unlock_irq(&kmap_lock)
+#define lock_kmap_any(flags) spin_lock_irqsave(&kmap_lock, flags)
+#define unlock_kmap_any(flags) spin_unlock_irqrestore(&kmap_lock, flags)
+#else
+#define lock_kmap() spin_lock(&kmap_lock)
+#define unlock_kmap() spin_unlock(&kmap_lock)
+#define lock_kmap_any(flags) \
+ do { spin_lock(&kmap_lock); (void)(flags); } while (0)
+#define unlock_kmap_any(flags) \
+ do { spin_unlock(&kmap_lock); (void)(flags); } while (0)
+#endif
+
static void flush_all_zero_pkmaps(void)
{
int i;
+ int need_flush = 0;
flush_cache_kmaps();
&pkmap_page_table[i]);
set_page_address(page, NULL);
+ need_flush = 1;
}
- flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
+ if (need_flush)
+ flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
+}
+
+/**
+ * kmap_flush_unused - flush all unused kmap mappings in order to remove stray mappings
+ */
+void kmap_flush_unused(void)
+{
+ lock_kmap();
+ flush_all_zero_pkmaps();
+ unlock_kmap();
}
static inline unsigned long map_new_virtual(struct page *page)
__set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&pkmap_map_wait, &wait);
- spin_unlock(&kmap_lock);
+ unlock_kmap();
schedule();
remove_wait_queue(&pkmap_map_wait, &wait);
- spin_lock(&kmap_lock);
+ lock_kmap();
/* Somebody else might have mapped it while we slept */
if (page_address(page))
return vaddr;
}
-void fastcall *kmap_high(struct page *page)
+/**
+ * kmap_high - map a highmem page into memory
+ * @page: &struct page to map
+ *
+ * Returns the page's virtual memory address.
+ *
+ * We cannot call this from interrupts, as it may block.
+ */
+void *kmap_high(struct page *page)
{
unsigned long vaddr;
/*
* For highmem pages, we can't trust "virtual" until
* after we have the lock.
- *
- * We cannot call this from interrupts, as it may block
*/
- spin_lock(&kmap_lock);
+ lock_kmap();
vaddr = (unsigned long)page_address(page);
if (!vaddr)
vaddr = map_new_virtual(page);
pkmap_count[PKMAP_NR(vaddr)]++;
BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2);
- spin_unlock(&kmap_lock);
+ unlock_kmap();
return (void*) vaddr;
}
EXPORT_SYMBOL(kmap_high);
-void fastcall kunmap_high(struct page *page)
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+/**
+ * kmap_high_get - pin a highmem page into memory
+ * @page: &struct page to pin
+ *
+ * Returns the page's current virtual memory address, or NULL if no mapping
+ * exists. If and only if a non null address is returned then a
+ * matching call to kunmap_high() is necessary.
+ *
+ * This can be called from any context.
+ */
+void *kmap_high_get(struct page *page)
+{
+ unsigned long vaddr, flags;
+
+ lock_kmap_any(flags);
+ vaddr = (unsigned long)page_address(page);
+ if (vaddr) {
+ BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 1);
+ pkmap_count[PKMAP_NR(vaddr)]++;
+ }
+ unlock_kmap_any(flags);
+ return (void*) vaddr;
+}
+#endif
+
+/**
+ * kunmap_high - map a highmem page into memory
+ * @page: &struct page to unmap
+ *
+ * If ARCH_NEEDS_KMAP_HIGH_GET is not defined then this may be called
+ * only from user context.
+ */
+void kunmap_high(struct page *page)
{
unsigned long vaddr;
unsigned long nr;
+ unsigned long flags;
int need_wakeup;
- spin_lock(&kmap_lock);
+ lock_kmap_any(flags);
vaddr = (unsigned long)page_address(page);
BUG_ON(!vaddr);
nr = PKMAP_NR(vaddr);
*/
need_wakeup = waitqueue_active(&pkmap_map_wait);
}
- spin_unlock(&kmap_lock);
+ unlock_kmap_any(flags);
/* do wake-up, if needed, race-free outside of the spin lock */
if (need_wakeup)
return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)];
}
+/**
+ * page_address - get the mapped virtual address of a page
+ * @page: &struct page to get the virtual address of
+ *
+ * Returns the page's virtual address.
+ */
void *page_address(struct page *page)
{
unsigned long flags;
EXPORT_SYMBOL(page_address);
+/**
+ * set_page_address - set a page's virtual address
+ * @page: &struct page to set
+ * @virtual: virtual address to use
+ */
void set_page_address(struct page *page, void *virtual)
{
unsigned long flags;
Code Review / linux-2.6.git / blobdiff