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-rw-r--r--linux-2.6-xen-sparse/mm/highmem.c613
1 files changed, 0 insertions, 613 deletions
diff --git a/linux-2.6-xen-sparse/mm/highmem.c b/linux-2.6-xen-sparse/mm/highmem.c
deleted file mode 100644
index 821d4cd1f6..0000000000
--- a/linux-2.6-xen-sparse/mm/highmem.c
+++ /dev/null
@@ -1,613 +0,0 @@
-/*
- * High memory handling common code and variables.
- *
- * (C) 1999 Andrea Arcangeli, SuSE GmbH, andrea@suse.de
- * Gerhard Wichert, Siemens AG, Gerhard.Wichert@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * 64-bit physical space. With current x86 CPUs this
- * means up to 64 Gigabytes physical RAM.
- *
- * Rewrote high memory support to move the page cache into
- * high memory. Implemented permanent (schedulable) kmaps
- * based on Linus' idea.
- *
- * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
- */
-
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/swap.h>
-#include <linux/bio.h>
-#include <linux/pagemap.h>
-#include <linux/mempool.h>
-#include <linux/blkdev.h>
-#include <linux/init.h>
-#include <linux/hash.h>
-#include <linux/highmem.h>
-#include <linux/blktrace_api.h>
-#include <asm/tlbflush.h>
-
-static mempool_t *page_pool, *isa_page_pool;
-
-static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data)
-{
- return mempool_alloc_pages(gfp_mask | GFP_DMA, data);
-}
-
-/*
- * Virtual_count is not a pure "count".
- * 0 means that it is not mapped, and has not been mapped
- * since a TLB flush - it is usable.
- * 1 means that there are no users, but it has been mapped
- * since the last TLB flush - so we can't use it.
- * n means that there are (n-1) current users of it.
- */
-#ifdef CONFIG_HIGHMEM
-
-static int pkmap_count[LAST_PKMAP];
-static unsigned int last_pkmap_nr;
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock);
-
-pte_t * pkmap_page_table;
-
-static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
-
-static void flush_all_zero_pkmaps(void)
-{
- int i;
-
- flush_cache_kmaps();
-
- for (i = 0; i < LAST_PKMAP; i++) {
- struct page *page;
-
- /*
- * zero means we don't have anything to do,
- * >1 means that it is still in use. Only
- * a count of 1 means that it is free but
- * needs to be unmapped
- */
- if (pkmap_count[i] != 1)
- continue;
- pkmap_count[i] = 0;
-
- /* sanity check */
- BUG_ON(pte_none(pkmap_page_table[i]));
-
- /*
- * Don't need an atomic fetch-and-clear op here;
- * no-one has the page mapped, and cannot get at
- * its virtual address (and hence PTE) without first
- * getting the kmap_lock (which is held here).
- * So no dangers, even with speculative execution.
- */
- page = pte_page(pkmap_page_table[i]);
- pte_clear(&init_mm, (unsigned long)page_address(page),
- &pkmap_page_table[i]);
-
- set_page_address(page, NULL);
- }
- flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
-}
-
-static inline unsigned long map_new_virtual(struct page *page)
-{
- unsigned long vaddr;
- int count;
-
-start:
- count = LAST_PKMAP;
- /* Find an empty entry */
- for (;;) {
- last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK;
- if (!last_pkmap_nr) {
- flush_all_zero_pkmaps();
- count = LAST_PKMAP;
- }
- if (!pkmap_count[last_pkmap_nr])
- break; /* Found a usable entry */
- if (--count)
- continue;
-
- /*
- * Sleep for somebody else to unmap their entries
- */
- {
- DECLARE_WAITQUEUE(wait, current);
-
- __set_current_state(TASK_UNINTERRUPTIBLE);
- add_wait_queue(&pkmap_map_wait, &wait);
- spin_unlock(&kmap_lock);
- schedule();
- remove_wait_queue(&pkmap_map_wait, &wait);
- spin_lock(&kmap_lock);
-
- /* Somebody else might have mapped it while we slept */
- if (page_address(page))
- return (unsigned long)page_address(page);
-
- /* Re-start */
- goto start;
- }
- }
- vaddr = PKMAP_ADDR(last_pkmap_nr);
- set_pte_at(&init_mm, vaddr,
- &(pkmap_page_table[last_pkmap_nr]), mk_pte(page, kmap_prot));
-
- pkmap_count[last_pkmap_nr] = 1;
- set_page_address(page, (void *)vaddr);
-
- return vaddr;
-}
-
-#ifdef CONFIG_XEN
-void kmap_flush_unused(void)
-{
- spin_lock(&kmap_lock);
- flush_all_zero_pkmaps();
- spin_unlock(&kmap_lock);
-}
-
-EXPORT_SYMBOL(kmap_flush_unused);
-#endif
-
-void fastcall *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);
- 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);
- return (void*) vaddr;
-}
-
-EXPORT_SYMBOL(kmap_high);
-
-void fastcall kunmap_high(struct page *page)
-{
- unsigned long vaddr;
- unsigned long nr;
- int need_wakeup;
-
- spin_lock(&kmap_lock);
- vaddr = (unsigned long)page_address(page);
- BUG_ON(!vaddr);
- nr = PKMAP_NR(vaddr);
-
- /*
- * A count must never go down to zero
- * without a TLB flush!
- */
- need_wakeup = 0;
- switch (--pkmap_count[nr]) {
- case 0:
- BUG();
- case 1:
- /*
- * Avoid an unnecessary wake_up() function call.
- * The common case is pkmap_count[] == 1, but
- * no waiters.
- * The tasks queued in the wait-queue are guarded
- * by both the lock in the wait-queue-head and by
- * the kmap_lock. As the kmap_lock is held here,
- * no need for the wait-queue-head's lock. Simply
- * test if the queue is empty.
- */
- need_wakeup = waitqueue_active(&pkmap_map_wait);
- }
- spin_unlock(&kmap_lock);
-
- /* do wake-up, if needed, race-free outside of the spin lock */
- if (need_wakeup)
- wake_up(&pkmap_map_wait);
-}
-
-EXPORT_SYMBOL(kunmap_high);
-
-#define POOL_SIZE 64
-
-static __init int init_emergency_pool(void)
-{
- struct sysinfo i;
- si_meminfo(&i);
- si_swapinfo(&i);
-
- if (!i.totalhigh)
- return 0;
-
- page_pool = mempool_create_page_pool(POOL_SIZE, 0);
- BUG_ON(!page_pool);
- printk("highmem bounce pool size: %d pages\n", POOL_SIZE);
-
- return 0;
-}
-
-__initcall(init_emergency_pool);
-
-/*
- * highmem version, map in to vec
- */
-static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)
-{
- unsigned long flags;
- unsigned char *vto;
-
- local_irq_save(flags);
- vto = kmap_atomic(to->bv_page, KM_BOUNCE_READ);
- memcpy(vto + to->bv_offset, vfrom, to->bv_len);
- kunmap_atomic(vto, KM_BOUNCE_READ);
- local_irq_restore(flags);
-}
-
-#else /* CONFIG_HIGHMEM */
-
-#define bounce_copy_vec(to, vfrom) \
- memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len)
-
-#endif
-
-#define ISA_POOL_SIZE 16
-
-/*
- * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA
- * as the max address, so check if the pool has already been created.
- */
-int init_emergency_isa_pool(void)
-{
- if (isa_page_pool)
- return 0;
-
- isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa,
- mempool_free_pages, (void *) 0);
- BUG_ON(!isa_page_pool);
-
- printk("isa bounce pool size: %d pages\n", ISA_POOL_SIZE);
- return 0;
-}
-
-/*
- * Simple bounce buffer support for highmem pages. Depending on the
- * queue gfp mask set, *to may or may not be a highmem page. kmap it
- * always, it will do the Right Thing
- */
-static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
-{
- unsigned char *vfrom;
- struct bio_vec *tovec, *fromvec;
- int i;
-
- __bio_for_each_segment(tovec, to, i, 0) {
- fromvec = from->bi_io_vec + i;
-
- /*
- * not bounced
- */
- if (tovec->bv_page == fromvec->bv_page)
- continue;
-
- /*
- * fromvec->bv_offset and fromvec->bv_len might have been
- * modified by the block layer, so use the original copy,
- * bounce_copy_vec already uses tovec->bv_len
- */
- vfrom = page_address(fromvec->bv_page) + tovec->bv_offset;
-
- flush_dcache_page(tovec->bv_page);
- bounce_copy_vec(tovec, vfrom);
- }
-}
-
-static void bounce_end_io(struct bio *bio, mempool_t *pool, int err)
-{
- struct bio *bio_orig = bio->bi_private;
- struct bio_vec *bvec, *org_vec;
- int i;
-
- if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
- set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags);
-
- /*
- * free up bounce indirect pages used
- */
- __bio_for_each_segment(bvec, bio, i, 0) {
- org_vec = bio_orig->bi_io_vec + i;
- if (bvec->bv_page == org_vec->bv_page)
- continue;
-
- dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
- mempool_free(bvec->bv_page, pool);
- }
-
- bio_endio(bio_orig, bio_orig->bi_size, err);
- bio_put(bio);
-}
-
-static int bounce_end_io_write(struct bio *bio, unsigned int bytes_done, int err)
-{
- if (bio->bi_size)
- return 1;
-
- bounce_end_io(bio, page_pool, err);
- return 0;
-}
-
-static int bounce_end_io_write_isa(struct bio *bio, unsigned int bytes_done, int err)
-{
- if (bio->bi_size)
- return 1;
-
- bounce_end_io(bio, isa_page_pool, err);
- return 0;
-}
-
-static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err)
-{
- struct bio *bio_orig = bio->bi_private;
-
- if (test_bit(BIO_UPTODATE, &bio->bi_flags))
- copy_to_high_bio_irq(bio_orig, bio);
-
- bounce_end_io(bio, pool, err);
-}
-
-static int bounce_end_io_read(struct bio *bio, unsigned int bytes_done, int err)
-{
- if (bio->bi_size)
- return 1;
-
- __bounce_end_io_read(bio, page_pool, err);
- return 0;
-}
-
-static int bounce_end_io_read_isa(struct bio *bio, unsigned int bytes_done, int err)
-{
- if (bio->bi_size)
- return 1;
-
- __bounce_end_io_read(bio, isa_page_pool, err);
- return 0;
-}
-
-static void __blk_queue_bounce(request_queue_t *q, struct bio **bio_orig,
- mempool_t *pool)
-{
- struct page *page;
- struct bio *bio = NULL;
- int i, rw = bio_data_dir(*bio_orig);
- struct bio_vec *to, *from;
-
- bio_for_each_segment(from, *bio_orig, i) {
- page = from->bv_page;
-
- /*
- * is destination page below bounce pfn?
- */
- if (page_to_pfn(page) < q->bounce_pfn)
- continue;
-
- /*
- * irk, bounce it
- */
- if (!bio)
- bio = bio_alloc(GFP_NOIO, (*bio_orig)->bi_vcnt);
-
- to = bio->bi_io_vec + i;
-
- to->bv_page = mempool_alloc(pool, q->bounce_gfp);
- to->bv_len = from->bv_len;
- to->bv_offset = from->bv_offset;
- inc_zone_page_state(to->bv_page, NR_BOUNCE);
-
- if (rw == WRITE) {
- char *vto, *vfrom;
-
- flush_dcache_page(from->bv_page);
- vto = page_address(to->bv_page) + to->bv_offset;
- vfrom = kmap(from->bv_page) + from->bv_offset;
- memcpy(vto, vfrom, to->bv_len);
- kunmap(from->bv_page);
- }
- }
-
- /*
- * no pages bounced
- */
- if (!bio)
- return;
-
- /*
- * at least one page was bounced, fill in possible non-highmem
- * pages
- */
- __bio_for_each_segment(from, *bio_orig, i, 0) {
- to = bio_iovec_idx(bio, i);
- if (!to->bv_page) {
- to->bv_page = from->bv_page;
- to->bv_len = from->bv_len;
- to->bv_offset = from->bv_offset;
- }
- }
-
- bio->bi_bdev = (*bio_orig)->bi_bdev;
- bio->bi_flags |= (1 << BIO_BOUNCED);
- bio->bi_sector = (*bio_orig)->bi_sector;
- bio->bi_rw = (*bio_orig)->bi_rw;
-
- bio->bi_vcnt = (*bio_orig)->bi_vcnt;
- bio->bi_idx = (*bio_orig)->bi_idx;
- bio->bi_size = (*bio_orig)->bi_size;
-
- if (pool == page_pool) {
- bio->bi_end_io = bounce_end_io_write;
- if (rw == READ)
- bio->bi_end_io = bounce_end_io_read;
- } else {
- bio->bi_end_io = bounce_end_io_write_isa;
- if (rw == READ)
- bio->bi_end_io = bounce_end_io_read_isa;
- }
-
- bio->bi_private = *bio_orig;
- *bio_orig = bio;
-}
-
-void blk_queue_bounce(request_queue_t *q, struct bio **bio_orig)
-{
- mempool_t *pool;
-
- /*
- * for non-isa bounce case, just check if the bounce pfn is equal
- * to or bigger than the highest pfn in the system -- in that case,
- * don't waste time iterating over bio segments
- */
- if (!(q->bounce_gfp & GFP_DMA)) {
- if (q->bounce_pfn >= blk_max_pfn)
- return;
- pool = page_pool;
- } else {
- BUG_ON(!isa_page_pool);
- pool = isa_page_pool;
- }
-
- blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
-
- /*
- * slow path
- */
- __blk_queue_bounce(q, bio_orig, pool);
-}
-
-EXPORT_SYMBOL(blk_queue_bounce);
-
-#if defined(HASHED_PAGE_VIRTUAL)
-
-#define PA_HASH_ORDER 7
-
-/*
- * Describes one page->virtual association
- */
-struct page_address_map {
- struct page *page;
- void *virtual;
- struct list_head list;
-};
-
-/*
- * page_address_map freelist, allocated from page_address_maps.
- */
-static struct list_head page_address_pool; /* freelist */
-static spinlock_t pool_lock; /* protects page_address_pool */
-
-/*
- * Hash table bucket
- */
-static struct page_address_slot {
- struct list_head lh; /* List of page_address_maps */
- spinlock_t lock; /* Protect this bucket's list */
-} ____cacheline_aligned_in_smp page_address_htable[1<<PA_HASH_ORDER];
-
-static struct page_address_slot *page_slot(struct page *page)
-{
- return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)];
-}
-
-void *page_address(struct page *page)
-{
- unsigned long flags;
- void *ret;
- struct page_address_slot *pas;
-
- if (!PageHighMem(page))
- return lowmem_page_address(page);
-
- pas = page_slot(page);
- ret = NULL;
- spin_lock_irqsave(&pas->lock, flags);
- if (!list_empty(&pas->lh)) {
- struct page_address_map *pam;
-
- list_for_each_entry(pam, &pas->lh, list) {
- if (pam->page == page) {
- ret = pam->virtual;
- goto done;
- }
- }
- }
-done:
- spin_unlock_irqrestore(&pas->lock, flags);
- return ret;
-}
-
-EXPORT_SYMBOL(page_address);
-
-void set_page_address(struct page *page, void *virtual)
-{
- unsigned long flags;
- struct page_address_slot *pas;
- struct page_address_map *pam;
-
- BUG_ON(!PageHighMem(page));
-
- pas = page_slot(page);
- if (virtual) { /* Add */
- BUG_ON(list_empty(&page_address_pool));
-
- spin_lock_irqsave(&pool_lock, flags);
- pam = list_entry(page_address_pool.next,
- struct page_address_map, list);
- list_del(&pam->list);
- spin_unlock_irqrestore(&pool_lock, flags);
-
- pam->page = page;
- pam->virtual = virtual;
-
- spin_lock_irqsave(&pas->lock, flags);
- list_add_tail(&pam->list, &pas->lh);
- spin_unlock_irqrestore(&pas->lock, flags);
- } else { /* Remove */
- spin_lock_irqsave(&pas->lock, flags);
- list_for_each_entry(pam, &pas->lh, list) {
- if (pam->page == page) {
- list_del(&pam->list);
- spin_unlock_irqrestore(&pas->lock, flags);
- spin_lock_irqsave(&pool_lock, flags);
- list_add_tail(&pam->list, &page_address_pool);
- spin_unlock_irqrestore(&pool_lock, flags);
- goto done;
- }
- }
- spin_unlock_irqrestore(&pas->lock, flags);
- }
-done:
- return;
-}
-
-static struct page_address_map page_address_maps[LAST_PKMAP];
-
-void __init page_address_init(void)
-{
- int i;
-
- INIT_LIST_HEAD(&page_address_pool);
- for (i = 0; i < ARRAY_SIZE(page_address_maps); i++)
- list_add(&page_address_maps[i].list, &page_address_pool);
- for (i = 0; i < ARRAY_SIZE(page_address_htable); i++) {
- INIT_LIST_HEAD(&page_address_htable[i].lh);
- spin_lock_init(&page_address_htable[i].lock);
- }
- spin_lock_init(&pool_lock);
-}
-
-#endif /* defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) */
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-23 20:13:58 +0000