[PATCH] change gen_pool allocator to not touch managed memory
Modify the gen_pool allocator (lib/genalloc.c) to utilize a bitmap scheme instead of the buddy scheme. The purpose of this change is to eliminate the touching of the actual memory being allocated. Since the change modifies the interface, a change to the uncached allocator (arch/ia64/kernel/uncached.c) is also required. Both Andrey Volkov and Jes Sorenson have expressed a desire that the gen_pool allocator not write to the memory being managed. See the following: http://marc.theaimsgroup.com/?l=linux-kernel&m=113518602713125&w=2 http://marc.theaimsgroup.com/?l=linux-kernel&m=113533568827916&w=2 Signed-off-by: Dean Nelson <dcn@sgi.com> Cc: Andrey Volkov <avolkov@varma-el.com> Acked-by: Jes Sorensen <jes@trained-monkey.org> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Dean Nelson
Linus Torvalds
Родитель
833423143c
Коммит
929f97276b
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@ -1,5 +1,5 @@
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/*
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* Copyright (C) 2001-2005 Silicon Graphics, Inc. All rights reserved.
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* Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of version 2 of the GNU General Public License
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@ -29,15 +29,8 @@
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#include <asm/tlbflush.h>
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#include <asm/sn/arch.h>
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#define DEBUG 0
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#if DEBUG
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#define dprintk printk
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#else
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#define dprintk(x...) do { } while (0)
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#endif
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void __init efi_memmap_walk_uc (efi_freemem_callback_t callback);
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extern void __init efi_memmap_walk_uc(efi_freemem_callback_t, void *);
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#define MAX_UNCACHED_GRANULES 5
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static int allocated_granules;
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@ -60,6 +53,7 @@ static void uncached_ipi_visibility(void *data)
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static void uncached_ipi_mc_drain(void *data)
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{
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int status;
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status = ia64_pal_mc_drain();
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if (status)
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printk(KERN_WARNING "ia64_pal_mc_drain() failed with %i on "
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@ -67,30 +61,35 @@ static void uncached_ipi_mc_drain(void *data)
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}
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static unsigned long
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uncached_get_new_chunk(struct gen_pool *poolp)
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/*
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* Add a new chunk of uncached memory pages to the specified pool.
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*
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* @pool: pool to add new chunk of uncached memory to
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* @nid: node id of node to allocate memory from, or -1
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*
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* This is accomplished by first allocating a granule of cached memory pages
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* and then converting them to uncached memory pages.
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*/
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static int uncached_add_chunk(struct gen_pool *pool, int nid)
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{
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struct page *page;
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void *tmp;
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int status, i;
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unsigned long addr, node;
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unsigned long c_addr, uc_addr;
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if (allocated_granules >= MAX_UNCACHED_GRANULES)
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return 0;
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return -1;
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node = poolp->private;
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page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO,
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/* attempt to allocate a granule's worth of cached memory pages */
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page = alloc_pages_node(nid, GFP_KERNEL | __GFP_ZERO,
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IA64_GRANULE_SHIFT-PAGE_SHIFT);
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dprintk(KERN_INFO "get_new_chunk page %p, addr %lx\n",
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page, (unsigned long)(page-vmem_map) << PAGE_SHIFT);
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/*
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* Do magic if no mem on local node! XXX
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*/
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if (!page)
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return 0;
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tmp = page_address(page);
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return -1;
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/* convert the memory pages from cached to uncached */
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c_addr = (unsigned long)page_address(page);
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uc_addr = c_addr - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
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/*
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* There's a small race here where it's possible for someone to
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@ -100,76 +99,90 @@ uncached_get_new_chunk(struct gen_pool *poolp)
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for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
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SetPageUncached(&page[i]);
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flush_tlb_kernel_range(tmp, tmp + IA64_GRANULE_SIZE);
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flush_tlb_kernel_range(uc_addr, uc_adddr + IA64_GRANULE_SIZE);
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status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
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dprintk(KERN_INFO "pal_prefetch_visibility() returns %i on cpu %i\n",
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status, raw_smp_processor_id());
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if (!status) {
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status = smp_call_function(uncached_ipi_visibility, NULL, 0, 1);
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if (status)
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printk(KERN_WARNING "smp_call_function failed for "
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"uncached_ipi_visibility! (%i)\n", status);
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goto failed;
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}
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preempt_disable();
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if (ia64_platform_is("sn2"))
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sn_flush_all_caches((unsigned long)tmp, IA64_GRANULE_SIZE);
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sn_flush_all_caches(uc_addr, IA64_GRANULE_SIZE);
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else
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flush_icache_range((unsigned long)tmp,
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(unsigned long)tmp+IA64_GRANULE_SIZE);
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flush_icache_range(uc_addr, uc_addr + IA64_GRANULE_SIZE);
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/* flush the just introduced uncached translation from the TLB */
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local_flush_tlb_all();
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preempt_enable();
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ia64_pal_mc_drain();
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status = smp_call_function(uncached_ipi_mc_drain, NULL, 0, 1);
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if (status)
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printk(KERN_WARNING "smp_call_function failed for "
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"uncached_ipi_mc_drain! (%i)\n", status);
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goto failed;
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addr = (unsigned long)tmp - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
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/*
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* The chunk of memory pages has been converted to uncached so now we
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* can add it to the pool.
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*/
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status = gen_pool_add(pool, uc_addr, IA64_GRANULE_SIZE, nid);
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if (status)
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goto failed;
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allocated_granules++;
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return addr;
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return 0;
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/* failed to convert or add the chunk so give it back to the kernel */
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failed:
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for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
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ClearPageUncached(&page[i]);
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free_pages(c_addr, IA64_GRANULE_SHIFT-PAGE_SHIFT);
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return -1;
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}
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/*
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* uncached_alloc_page
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*
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* @starting_nid: node id of node to start with, or -1
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*
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* Allocate 1 uncached page. Allocates on the requested node. If no
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* uncached pages are available on the requested node, roundrobin starting
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* with higher nodes.
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* with the next higher node.
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*/
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unsigned long
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uncached_alloc_page(int nid)
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unsigned long uncached_alloc_page(int starting_nid)
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{
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unsigned long maddr;
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unsigned long uc_addr;
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struct gen_pool *pool;
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int nid;
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maddr = gen_pool_alloc(uncached_pool[nid], PAGE_SIZE);
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if (unlikely(starting_nid >= MAX_NUMNODES))
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return 0;
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dprintk(KERN_DEBUG "uncached_alloc_page returns %lx on node %i\n",
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maddr, nid);
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if (starting_nid < 0)
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starting_nid = numa_node_id();
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nid = starting_nid;
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/*
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* If no memory is availble on our local node, try the
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* remaining nodes in the system.
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*/
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if (!maddr) {
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int i;
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do {
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if (!node_online(nid))
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continue;
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pool = uncached_pool[nid];
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if (pool == NULL)
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continue;
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do {
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uc_addr = gen_pool_alloc(pool, PAGE_SIZE);
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if (uc_addr != 0)
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return uc_addr;
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} while (uncached_add_chunk(pool, nid) == 0);
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for (i = MAX_NUMNODES - 1; i >= 0; i--) {
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if (i == nid || !node_online(i))
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continue;
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maddr = gen_pool_alloc(uncached_pool[i], PAGE_SIZE);
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dprintk(KERN_DEBUG "uncached_alloc_page alternate search "
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"returns %lx on node %i\n", maddr, i);
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if (maddr) {
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break;
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}
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}
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}
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} while ((nid = (nid + 1) % MAX_NUMNODES) != starting_nid);
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return maddr;
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return 0;
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}
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EXPORT_SYMBOL(uncached_alloc_page);
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@ -177,21 +190,22 @@ EXPORT_SYMBOL(uncached_alloc_page);
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/*
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* uncached_free_page
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*
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* @uc_addr: uncached address of page to free
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*
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* Free a single uncached page.
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*/
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void
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uncached_free_page(unsigned long maddr)
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void uncached_free_page(unsigned long uc_addr)
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{
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int node;
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int nid = paddr_to_nid(uc_addr - __IA64_UNCACHED_OFFSET);
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struct gen_pool *pool = uncached_pool[nid];
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node = paddr_to_nid(maddr - __IA64_UNCACHED_OFFSET);
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if (unlikely(pool == NULL))
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return;
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dprintk(KERN_DEBUG "uncached_free_page(%lx) on node %i\n", maddr, node);
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if ((uc_addr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
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panic("uncached_free_page invalid address %lx\n", uc_addr);
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if ((maddr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
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panic("uncached_free_page invalid address %lx\n", maddr);
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gen_pool_free(uncached_pool[node], maddr, PAGE_SIZE);
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gen_pool_free(pool, uc_addr, PAGE_SIZE);
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}
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EXPORT_SYMBOL(uncached_free_page);
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@ -199,43 +213,39 @@ EXPORT_SYMBOL(uncached_free_page);
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/*
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* uncached_build_memmap,
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*
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* @uc_start: uncached starting address of a chunk of uncached memory
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* @uc_end: uncached ending address of a chunk of uncached memory
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* @arg: ignored, (NULL argument passed in on call to efi_memmap_walk_uc())
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*
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* Called at boot time to build a map of pages that can be used for
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* memory special operations.
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*/
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static int __init
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uncached_build_memmap(unsigned long start, unsigned long end, void *arg)
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static int __init uncached_build_memmap(unsigned long uc_start,
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unsigned long uc_end, void *arg)
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{
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long length = end - start;
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int node;
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dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end);
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int nid = paddr_to_nid(uc_start - __IA64_UNCACHED_OFFSET);
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struct gen_pool *pool = uncached_pool[nid];
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size_t size = uc_end - uc_start;
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touch_softlockup_watchdog();
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memset((char *)start, 0, length);
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node = paddr_to_nid(start - __IA64_UNCACHED_OFFSET);
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for (; start < end ; start += PAGE_SIZE) {
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dprintk(KERN_INFO "sticking %lx into the pool!\n", start);
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gen_pool_free(uncached_pool[node], start, PAGE_SIZE);
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if (pool != NULL) {
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memset((char *)uc_start, 0, size);
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(void) gen_pool_add(pool, uc_start, size, nid);
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}
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return 0;
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}
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static int __init uncached_init(void) {
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int i;
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static int __init uncached_init(void)
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{
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int nid;
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for (i = 0; i < MAX_NUMNODES; i++) {
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if (!node_online(i))
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continue;
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uncached_pool[i] = gen_pool_create(0, IA64_GRANULE_SHIFT,
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&uncached_get_new_chunk, i);
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for_each_online_node(nid) {
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uncached_pool[nid] = gen_pool_create(PAGE_SHIFT, nid);
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}
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efi_memmap_walk_uc(uncached_build_memmap);
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efi_memmap_walk_uc(uncached_build_memmap, NULL);
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return 0;
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}
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@ -3,11 +3,12 @@
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001-2003 Silicon Graphics, Inc. All rights reserved.
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* Copyright (C) 2001-2003, 2006 Silicon Graphics, Inc. All rights reserved.
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*
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*/
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#include <linux/module.h>
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#include <asm/pgalloc.h>
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#include <asm/sn/arch.h>
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/**
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* sn_flush_all_caches - flush a range of address from all caches (incl. L4)
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@ -17,18 +18,24 @@
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* Flush a range of addresses from all caches including L4.
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* All addresses fully or partially contained within
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* @flush_addr to @flush_addr + @bytes are flushed
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* from the all caches.
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* from all caches.
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*/
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void
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sn_flush_all_caches(long flush_addr, long bytes)
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{
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flush_icache_range(flush_addr, flush_addr+bytes);
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unsigned long addr = flush_addr;
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/* SHub1 requires a cached address */
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if (is_shub1() && (addr & RGN_BITS) == RGN_BASE(RGN_UNCACHED))
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addr = (addr - RGN_BASE(RGN_UNCACHED)) + RGN_BASE(RGN_KERNEL);
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flush_icache_range(addr, addr + bytes);
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/*
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* The last call may have returned before the caches
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* were actually flushed, so we call it again to make
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* sure.
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*/
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flush_icache_range(flush_addr, flush_addr+bytes);
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flush_icache_range(addr, addr + bytes);
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mb();
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}
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EXPORT_SYMBOL(sn_flush_all_caches);
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|
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@ -4,37 +4,32 @@
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* Uses for this includes on-device special memory, uncached memory
|
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* etc.
|
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*
|
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* This code is based on the buddy allocator found in the sym53c8xx_2
|
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* driver, adapted for general purpose use.
|
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*
|
||||
* This source code is licensed under the GNU General Public License,
|
||||
* Version 2. See the file COPYING for more details.
|
||||
*/
|
||||
|
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#include <linux/spinlock.h>
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|
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#define ALLOC_MIN_SHIFT 5 /* 32 bytes minimum */
|
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/*
|
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* Link between free memory chunks of a given size.
|
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*/
|
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struct gen_pool_link {
|
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struct gen_pool_link *next;
|
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};
|
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|
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/*
|
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* Memory pool descriptor.
|
||||
* General purpose special memory pool descriptor.
|
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*/
|
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struct gen_pool {
|
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spinlock_t lock;
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unsigned long (*get_new_chunk)(struct gen_pool *);
|
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struct gen_pool *next;
|
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struct gen_pool_link *h;
|
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unsigned long private;
|
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int max_chunk_shift;
|
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rwlock_t lock;
|
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struct list_head chunks; /* list of chunks in this pool */
|
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int min_alloc_order; /* minimum allocation order */
|
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};
|
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|
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unsigned long gen_pool_alloc(struct gen_pool *poolp, int size);
|
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void gen_pool_free(struct gen_pool *mp, unsigned long ptr, int size);
|
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struct gen_pool *gen_pool_create(int nr_chunks, int max_chunk_shift,
|
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unsigned long (*fp)(struct gen_pool *),
|
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unsigned long data);
|
||||
/*
|
||||
* General purpose special memory pool chunk descriptor.
|
||||
*/
|
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struct gen_pool_chunk {
|
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spinlock_t lock;
|
||||
struct list_head next_chunk; /* next chunk in pool */
|
||||
unsigned long start_addr; /* starting address of memory chunk */
|
||||
unsigned long end_addr; /* ending address of memory chunk */
|
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unsigned long bits[0]; /* bitmap for allocating memory chunk */
|
||||
};
|
||||
|
||||
extern struct gen_pool *gen_pool_create(int, int);
|
||||
extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
|
||||
extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
|
||||
extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
|
||||
|
|
|
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255
lib/genalloc.c
255
lib/genalloc.c
|
|
@ -4,10 +4,6 @@
|
|||
* Uses for this includes on-device special memory, uncached memory
|
||||
* etc.
|
||||
*
|
||||
* This code is based on the buddy allocator found in the sym53c8xx_2
|
||||
* driver Copyright (C) 1999-2001 Gerard Roudier <groudier@free.fr>,
|
||||
* and adapted for general purpose use.
|
||||
*
|
||||
* Copyright 2005 (C) Jes Sorensen <jes@trained-monkey.org>
|
||||
*
|
||||
* This source code is licensed under the GNU General Public License,
|
||||
|
|
@ -15,172 +11,155 @@
|
|||
*/
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/stddef.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/string.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/genalloc.h>
|
||||
|
||||
#include <asm/page.h>
|
||||
|
||||
|
||||
struct gen_pool *gen_pool_create(int nr_chunks, int max_chunk_shift,
|
||||
unsigned long (*fp)(struct gen_pool *),
|
||||
unsigned long data)
|
||||
/*
|
||||
* Create a new special memory pool.
|
||||
*
|
||||
* @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
|
||||
* @nid: node id of the node the pool structure should be allocated on, or -1
|
||||
*/
|
||||
struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
|
||||
{
|
||||
struct gen_pool *poolp;
|
||||
unsigned long tmp;
|
||||
int i;
|
||||
struct gen_pool *pool;
|
||||
|
||||
/*
|
||||
* This is really an arbitrary limit, +10 is enough for
|
||||
* IA64_GRANULE_SHIFT, aka 16MB. If anyone needs a large limit
|
||||
* this can be increased without problems.
|
||||
*/
|
||||
if ((max_chunk_shift > (PAGE_SHIFT + 10)) ||
|
||||
((max_chunk_shift < ALLOC_MIN_SHIFT) && max_chunk_shift))
|
||||
return NULL;
|
||||
|
||||
if (!max_chunk_shift)
|
||||
max_chunk_shift = PAGE_SHIFT;
|
||||
|
||||
poolp = kmalloc(sizeof(struct gen_pool), GFP_KERNEL);
|
||||
if (!poolp)
|
||||
return NULL;
|
||||
memset(poolp, 0, sizeof(struct gen_pool));
|
||||
poolp->h = kmalloc(sizeof(struct gen_pool_link) *
|
||||
(max_chunk_shift - ALLOC_MIN_SHIFT + 1),
|
||||
GFP_KERNEL);
|
||||
if (!poolp->h) {
|
||||
printk(KERN_WARNING "gen_pool_alloc() failed to allocate\n");
|
||||
kfree(poolp);
|
||||
return NULL;
|
||||
pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
|
||||
if (pool != NULL) {
|
||||
rwlock_init(&pool->lock);
|
||||
INIT_LIST_HEAD(&pool->chunks);
|
||||
pool->min_alloc_order = min_alloc_order;
|
||||
}
|
||||
memset(poolp->h, 0, sizeof(struct gen_pool_link) *
|
||||
(max_chunk_shift - ALLOC_MIN_SHIFT + 1));
|
||||
|
||||
spin_lock_init(&poolp->lock);
|
||||
poolp->get_new_chunk = fp;
|
||||
poolp->max_chunk_shift = max_chunk_shift;
|
||||
poolp->private = data;
|
||||
|
||||
for (i = 0; i < nr_chunks; i++) {
|
||||
tmp = poolp->get_new_chunk(poolp);
|
||||
printk(KERN_INFO "allocated %lx\n", tmp);
|
||||
if (!tmp)
|
||||
break;
|
||||
gen_pool_free(poolp, tmp, (1 << poolp->max_chunk_shift));
|
||||
}
|
||||
|
||||
return poolp;
|
||||
return pool;
|
||||
}
|
||||
EXPORT_SYMBOL(gen_pool_create);
|
||||
|
||||
|
||||
/*
|
||||
* Simple power of two buddy-like generic allocator.
|
||||
* Provides naturally aligned memory chunks.
|
||||
* Add a new chunk of memory to the specified pool.
|
||||
*
|
||||
* @pool: pool to add new memory chunk to
|
||||
* @addr: starting address of memory chunk to add to pool
|
||||
* @size: size in bytes of the memory chunk to add to pool
|
||||
* @nid: node id of the node the chunk structure and bitmap should be
|
||||
* allocated on, or -1
|
||||
*/
|
||||
unsigned long gen_pool_alloc(struct gen_pool *poolp, int size)
|
||||
int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
|
||||
int nid)
|
||||
{
|
||||
int j, i, s, max_chunk_size;
|
||||
unsigned long a, flags;
|
||||
struct gen_pool_link *h = poolp->h;
|
||||
struct gen_pool_chunk *chunk;
|
||||
int nbits = size >> pool->min_alloc_order;
|
||||
int nbytes = sizeof(struct gen_pool_chunk) +
|
||||
(nbits + BITS_PER_BYTE - 1) / BITS_PER_BYTE;
|
||||
|
||||
max_chunk_size = 1 << poolp->max_chunk_shift;
|
||||
chunk = kmalloc_node(nbytes, GFP_KERNEL, nid);
|
||||
if (unlikely(chunk == NULL))
|
||||
return -1;
|
||||
|
||||
if (size > max_chunk_size)
|
||||
memset(chunk, 0, nbytes);
|
||||
spin_lock_init(&chunk->lock);
|
||||
chunk->start_addr = addr;
|
||||
chunk->end_addr = addr + size;
|
||||
|
||||
write_lock(&pool->lock);
|
||||
list_add(&chunk->next_chunk, &pool->chunks);
|
||||
write_unlock(&pool->lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL(gen_pool_add);
|
||||
|
||||
|
||||
/*
|
||||
* Allocate the requested number of bytes from the specified pool.
|
||||
* Uses a first-fit algorithm.
|
||||
*
|
||||
* @pool: pool to allocate from
|
||||
* @size: number of bytes to allocate from the pool
|
||||
*/
|
||||
unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
|
||||
{
|
||||
struct list_head *_chunk;
|
||||
struct gen_pool_chunk *chunk;
|
||||
unsigned long addr, flags;
|
||||
int order = pool->min_alloc_order;
|
||||
int nbits, bit, start_bit, end_bit;
|
||||
|
||||
if (size == 0)
|
||||
return 0;
|
||||
|
||||
size = max(size, 1 << ALLOC_MIN_SHIFT);
|
||||
i = fls(size - 1);
|
||||
s = 1 << i;
|
||||
j = i -= ALLOC_MIN_SHIFT;
|
||||
nbits = (size + (1UL << order) - 1) >> order;
|
||||
|
||||
spin_lock_irqsave(&poolp->lock, flags);
|
||||
while (!h[j].next) {
|
||||
if (s == max_chunk_size) {
|
||||
struct gen_pool_link *ptr;
|
||||
spin_unlock_irqrestore(&poolp->lock, flags);
|
||||
ptr = (struct gen_pool_link *)poolp->get_new_chunk(poolp);
|
||||
spin_lock_irqsave(&poolp->lock, flags);
|
||||
h[j].next = ptr;
|
||||
if (h[j].next)
|
||||
h[j].next->next = NULL;
|
||||
break;
|
||||
read_lock(&pool->lock);
|
||||
list_for_each(_chunk, &pool->chunks) {
|
||||
chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
|
||||
|
||||
end_bit = (chunk->end_addr - chunk->start_addr) >> order;
|
||||
end_bit -= nbits + 1;
|
||||
|
||||
spin_lock_irqsave(&chunk->lock, flags);
|
||||
bit = -1;
|
||||
while (bit + 1 < end_bit) {
|
||||
bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
|
||||
if (bit >= end_bit)
|
||||
break;
|
||||
|
||||
start_bit = bit;
|
||||
if (nbits > 1) {
|
||||
bit = find_next_bit(chunk->bits, bit + nbits,
|
||||
bit + 1);
|
||||
if (bit - start_bit < nbits)
|
||||
continue;
|
||||
}
|
||||
|
||||
addr = chunk->start_addr +
|
||||
((unsigned long)start_bit << order);
|
||||
while (nbits--)
|
||||
__set_bit(start_bit++, &chunk->bits);
|
||||
spin_unlock_irqrestore(&chunk->lock, flags);
|
||||
read_unlock(&pool->lock);
|
||||
return addr;
|
||||
}
|
||||
j++;
|
||||
s <<= 1;
|
||||
spin_unlock_irqrestore(&chunk->lock, flags);
|
||||
}
|
||||
a = (unsigned long) h[j].next;
|
||||
if (a) {
|
||||
h[j].next = h[j].next->next;
|
||||
/*
|
||||
* This should be split into a seperate function doing
|
||||
* the chunk split in order to support custom
|
||||
* handling memory not physically accessible by host
|
||||
*/
|
||||
while (j > i) {
|
||||
j -= 1;
|
||||
s >>= 1;
|
||||
h[j].next = (struct gen_pool_link *) (a + s);
|
||||
h[j].next->next = NULL;
|
||||
}
|
||||
}
|
||||
spin_unlock_irqrestore(&poolp->lock, flags);
|
||||
return a;
|
||||
read_unlock(&pool->lock);
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL(gen_pool_alloc);
|
||||
|
||||
|
||||
/*
|
||||
* Counter-part of the generic allocator.
|
||||
* Free the specified memory back to the specified pool.
|
||||
*
|
||||
* @pool: pool to free to
|
||||
* @addr: starting address of memory to free back to pool
|
||||
* @size: size in bytes of memory to free
|
||||
*/
|
||||
void gen_pool_free(struct gen_pool *poolp, unsigned long ptr, int size)
|
||||
void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
|
||||
{
|
||||
struct gen_pool_link *q;
|
||||
struct gen_pool_link *h = poolp->h;
|
||||
unsigned long a, b, flags;
|
||||
int i, s, max_chunk_size;
|
||||
struct list_head *_chunk;
|
||||
struct gen_pool_chunk *chunk;
|
||||
unsigned long flags;
|
||||
int order = pool->min_alloc_order;
|
||||
int bit, nbits;
|
||||
|
||||
max_chunk_size = 1 << poolp->max_chunk_shift;
|
||||
nbits = (size + (1UL << order) - 1) >> order;
|
||||
|
||||
if (size > max_chunk_size)
|
||||
return;
|
||||
read_lock(&pool->lock);
|
||||
list_for_each(_chunk, &pool->chunks) {
|
||||
chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
|
||||
|
||||
size = max(size, 1 << ALLOC_MIN_SHIFT);
|
||||
i = fls(size - 1);
|
||||
s = 1 << i;
|
||||
i -= ALLOC_MIN_SHIFT;
|
||||
|
||||
a = ptr;
|
||||
|
||||
spin_lock_irqsave(&poolp->lock, flags);
|
||||
while (1) {
|
||||
if (s == max_chunk_size) {
|
||||
((struct gen_pool_link *)a)->next = h[i].next;
|
||||
h[i].next = (struct gen_pool_link *)a;
|
||||
if (addr >= chunk->start_addr && addr < chunk->end_addr) {
|
||||
BUG_ON(addr + size > chunk->end_addr);
|
||||
spin_lock_irqsave(&chunk->lock, flags);
|
||||
bit = (addr - chunk->start_addr) >> order;
|
||||
while (nbits--)
|
||||
__clear_bit(bit++, &chunk->bits);
|
||||
spin_unlock_irqrestore(&chunk->lock, flags);
|
||||
break;
|
||||
}
|
||||
b = a ^ s;
|
||||
q = &h[i];
|
||||
|
||||
while (q->next && q->next != (struct gen_pool_link *)b)
|
||||
q = q->next;
|
||||
|
||||
if (!q->next) {
|
||||
((struct gen_pool_link *)a)->next = h[i].next;
|
||||
h[i].next = (struct gen_pool_link *)a;
|
||||
break;
|
||||
}
|
||||
q->next = q->next->next;
|
||||
a = a & b;
|
||||
s <<= 1;
|
||||
i++;
|
||||
}
|
||||
spin_unlock_irqrestore(&poolp->lock, flags);
|
||||
BUG_ON(nbits > 0);
|
||||
read_unlock(&pool->lock);
|
||||
}
|
||||
EXPORT_SYMBOL(gen_pool_free);
|
||||
|
|
|
|||
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