From: kfraser@localhost.localdomain Date: Fri, 6 Oct 2006 09:30:43 +0000 (+0100) Subject: [BLK] tap: Allocate pages for foreign mappings individually rather than contiguously. X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15615^2~36 X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=db002ee4a03f1d5a0df42d3f25bcc21257ae20f6;p=xen.git [BLK] tap: Allocate pages for foreign mappings individually rather than contiguously. Signed-off-by: Keir Fraser --- diff --git a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c b/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c index bfd8dfb432..7f26492902 100644 --- a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c +++ b/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c @@ -186,16 +186,18 @@ static inline unsigned int RTN_PEND_IDX(pending_req_t *req, int idx) { #define BLKBACK_INVALID_HANDLE (~0) -typedef struct mmap_page { - unsigned long start; - struct page *mpage; -} mmap_page_t; +static struct page **foreign_pages[MAX_DYNAMIC_MEM]; +static inline unsigned long idx_to_kaddr( + unsigned int mmap_idx, unsigned int req_idx, unsigned int sg_idx) +{ + unsigned int arr_idx = req_idx*BLKIF_MAX_SEGMENTS_PER_REQUEST + sg_idx; + unsigned long pfn = page_to_pfn(foreign_pages[mmap_idx][arr_idx]); + return (unsigned long)pfn_to_kaddr(pfn); +} -static mmap_page_t mmap_start[MAX_DYNAMIC_MEM]; static unsigned short mmap_alloc = 0; static unsigned short mmap_lock = 0; static unsigned short mmap_inuse = 0; -static unsigned long *pending_addrs[MAX_DYNAMIC_MEM]; /****************************************************************** * GRANT HANDLES @@ -726,63 +728,33 @@ static void make_response(blkif_t *blkif, unsigned long id, static int req_increase(void) { int i, j; - struct page *page; - int ret; + struct page **pages = NULL; - ret = -EINVAL; if (mmap_alloc >= MAX_PENDING_REQS || mmap_lock) - goto done; - -#ifdef __ia64__ - extern unsigned long alloc_empty_foreign_map_page_range( - unsigned long pages); - mmap_start[mmap_alloc].start = (unsigned long) - alloc_empty_foreign_map_page_range(mmap_pages); -#else /* ! ia64 */ - page = balloon_alloc_empty_page_range(mmap_pages); - ret = -ENOMEM; - if (page == NULL) { - printk("%s balloon_alloc_empty_page_range gave NULL\n", __FUNCTION__); - goto done; - } - - /* Pin all of the pages. */ - for (i=0; i= 0) + balloon_free_empty_page(pages[i]); + goto out_of_memory; + } } - ret = 0; - - DPRINTK("%s: reqs=%d, pages=%d, mmap_vstart=0x%lx\n", - __FUNCTION__, blkif_reqs, mmap_pages, - mmap_start[mmap_alloc].start); - - BUG_ON(mmap_start[mmap_alloc].start == 0); + foreign_pages[mmap_alloc] = pages; - for (i = 0; i < mmap_pages; i++) - pending_addrs[mmap_alloc][i] = - mmap_start[mmap_alloc].start + (i << PAGE_SHIFT); + DPRINTK("%s: reqs=%d, pages=%d\n", + __FUNCTION__, blkif_reqs, mmap_pages); - for (i = 0; i < MAX_PENDING_REQS ; i++) { + for (i = 0; i < MAX_PENDING_REQS; i++) { list_add_tail(&pending_reqs[mmap_alloc][i].free_list, &pending_free); pending_reqs[mmap_alloc][i].mem_idx = mmap_alloc; @@ -793,30 +765,27 @@ static int req_increase(void) mmap_alloc++; DPRINTK("# MMAPs increased to %d\n",mmap_alloc); -done: - return ret; + return 0; + + out_of_memory: + kfree(pages); + kfree(pending_reqs[mmap_alloc]); + WPRINTK("%s: out of memory\n", __FUNCTION__); + return -ENOMEM; } static void mmap_req_del(int mmap) { int i; - struct page *page; - - /*Spinlock already acquired*/ - kfree(pending_reqs[mmap]); - kfree(pending_addrs[mmap]); -#ifdef __ia64__ - /*Not sure what goes here yet!*/ -#else + BUG_ON(!spin_is_locked(&pending_free_lock)); - /* Unpin all of the pages. */ - page = mmap_start[mmap].mpage; - for (i=0; imem_idx; for (i = 0; i < req->nr_pages; i++) { - kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, k_idx, i); + kvaddr = idx_to_kaddr(mmap_idx, k_idx, i); uvaddr = MMAP_VADDR(info->user_vstart, u_idx, i); khandle = &pending_handle(mmap_idx, k_idx, i); @@ -896,7 +865,7 @@ static void fast_flush_area(pending_req_t *req, int k_idx, int u_idx, int continue; } gnttab_set_unmap_op(&unmap[invcount], - MMAP_VADDR(mmap_start[mmap_idx].start, k_idx, i), + idx_to_kaddr(mmap_idx, k_idx, i), GNTMAP_host_map, khandle->kernel); invcount++; @@ -1030,9 +999,8 @@ static int blktap_read_ufe_ring(tap_blkif_t *info) struct page *pg; int offset; - uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, j); - kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, - pending_idx, j); + uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, j); + kvaddr = idx_to_kaddr(mmap_idx, pending_idx, j); pg = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT); ClearPageReserved(pg); @@ -1214,8 +1182,7 @@ static void dispatch_rw_block_io(blkif_t *blkif, uint32_t flags; uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, i); - kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, - pending_idx, i); + kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i); page = virt_to_page(kvaddr); sector = req->sector_number + (8*i); @@ -1267,8 +1234,7 @@ static void dispatch_rw_block_io(blkif_t *blkif, struct page *pg; uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, i/2); - kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, - pending_idx, i/2); + kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i/2); if (unlikely(map[i].status != 0)) { WPRINTK("invalid kernel buffer -- " @@ -1298,8 +1264,7 @@ static void dispatch_rw_block_io(blkif_t *blkif, unsigned long kvaddr; struct page *pg; - kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, - pending_idx, i); + kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i); pg = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT); SetPageReserved(pg); }