From 929f97276bcf7f4a95272ed08a85339b98ba210d Mon Sep 17 00:00:00 2001 From: Dean Nelson Date: Fri, 23 Jun 2006 02:03:21 -0700 Subject: [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 Cc: Andrey Volkov Acked-by: Jes Sorensen Cc: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ia64/kernel/uncached.c | 200 +++++++++++++++++++++------------------- arch/ia64/sn/kernel/sn2/cache.c | 15 ++- 2 files changed, 116 insertions(+), 99 deletions(-) (limited to 'arch/ia64') diff --git a/arch/ia64/kernel/uncached.c b/arch/ia64/kernel/uncached.c index fcd2bad0286..5f03b9e524d 100644 --- a/arch/ia64/kernel/uncached.c +++ b/arch/ia64/kernel/uncached.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2001-2005 Silicon Graphics, Inc. All rights reserved. + * Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights reserved. * * This program is free software; you can redistribute it and/or modify it * under the terms of version 2 of the GNU General Public License @@ -29,15 +29,8 @@ #include #include -#define DEBUG 0 -#if DEBUG -#define dprintk printk -#else -#define dprintk(x...) do { } while (0) -#endif - -void __init efi_memmap_walk_uc (efi_freemem_callback_t callback); +extern void __init efi_memmap_walk_uc(efi_freemem_callback_t, void *); #define MAX_UNCACHED_GRANULES 5 static int allocated_granules; @@ -60,6 +53,7 @@ static void uncached_ipi_visibility(void *data) static void uncached_ipi_mc_drain(void *data) { int status; + status = ia64_pal_mc_drain(); if (status) printk(KERN_WARNING "ia64_pal_mc_drain() failed with %i on " @@ -67,30 +61,35 @@ static void uncached_ipi_mc_drain(void *data) } -static unsigned long -uncached_get_new_chunk(struct gen_pool *poolp) +/* + * Add a new chunk of uncached memory pages to the specified pool. + * + * @pool: pool to add new chunk of uncached memory to + * @nid: node id of node to allocate memory from, or -1 + * + * This is accomplished by first allocating a granule of cached memory pages + * and then converting them to uncached memory pages. + */ +static int uncached_add_chunk(struct gen_pool *pool, int nid) { struct page *page; - void *tmp; int status, i; - unsigned long addr, node; + unsigned long c_addr, uc_addr; if (allocated_granules >= MAX_UNCACHED_GRANULES) - return 0; + return -1; + + /* attempt to allocate a granule's worth of cached memory pages */ - node = poolp->private; - page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, + page = alloc_pages_node(nid, GFP_KERNEL | __GFP_ZERO, IA64_GRANULE_SHIFT-PAGE_SHIFT); + if (!page) + return -1; - dprintk(KERN_INFO "get_new_chunk page %p, addr %lx\n", - page, (unsigned long)(page-vmem_map) << PAGE_SHIFT); + /* convert the memory pages from cached to uncached */ - /* - * Do magic if no mem on local node! XXX - */ - if (!page) - return 0; - tmp = page_address(page); + c_addr = (unsigned long)page_address(page); + uc_addr = c_addr - PAGE_OFFSET + __IA64_UNCACHED_OFFSET; /* * There's a small race here where it's possible for someone to @@ -100,76 +99,90 @@ uncached_get_new_chunk(struct gen_pool *poolp) for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++) SetPageUncached(&page[i]); - flush_tlb_kernel_range(tmp, tmp + IA64_GRANULE_SIZE); + flush_tlb_kernel_range(uc_addr, uc_adddr + IA64_GRANULE_SIZE); status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL); - - dprintk(KERN_INFO "pal_prefetch_visibility() returns %i on cpu %i\n", - status, raw_smp_processor_id()); - if (!status) { status = smp_call_function(uncached_ipi_visibility, NULL, 0, 1); if (status) - printk(KERN_WARNING "smp_call_function failed for " - "uncached_ipi_visibility! (%i)\n", status); + goto failed; } + preempt_disable(); + if (ia64_platform_is("sn2")) - sn_flush_all_caches((unsigned long)tmp, IA64_GRANULE_SIZE); + sn_flush_all_caches(uc_addr, IA64_GRANULE_SIZE); else - flush_icache_range((unsigned long)tmp, - (unsigned long)tmp+IA64_GRANULE_SIZE); + flush_icache_range(uc_addr, uc_addr + IA64_GRANULE_SIZE); + + /* flush the just introduced uncached translation from the TLB */ + local_flush_tlb_all(); + + preempt_enable(); ia64_pal_mc_drain(); status = smp_call_function(uncached_ipi_mc_drain, NULL, 0, 1); if (status) - printk(KERN_WARNING "smp_call_function failed for " - "uncached_ipi_mc_drain! (%i)\n", status); + goto failed; - addr = (unsigned long)tmp - PAGE_OFFSET + __IA64_UNCACHED_OFFSET; + /* + * The chunk of memory pages has been converted to uncached so now we + * can add it to the pool. + */ + status = gen_pool_add(pool, uc_addr, IA64_GRANULE_SIZE, nid); + if (status) + goto failed; allocated_granules++; - return addr; + return 0; + + /* failed to convert or add the chunk so give it back to the kernel */ +failed: + for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++) + ClearPageUncached(&page[i]); + + free_pages(c_addr, IA64_GRANULE_SHIFT-PAGE_SHIFT); + return -1; } /* * uncached_alloc_page * + * @starting_nid: node id of node to start with, or -1 + * * Allocate 1 uncached page. Allocates on the requested node. If no * uncached pages are available on the requested node, roundrobin starting - * with higher nodes. + * with the next higher node. */ -unsigned long -uncached_alloc_page(int nid) +unsigned long uncached_alloc_page(int starting_nid) { - unsigned long maddr; + unsigned long uc_addr; + struct gen_pool *pool; + int nid; - maddr = gen_pool_alloc(uncached_pool[nid], PAGE_SIZE); + if (unlikely(starting_nid >= MAX_NUMNODES)) + return 0; - dprintk(KERN_DEBUG "uncached_alloc_page returns %lx on node %i\n", - maddr, nid); + if (starting_nid < 0) + starting_nid = numa_node_id(); + nid = starting_nid; - /* - * If no memory is availble on our local node, try the - * remaining nodes in the system. - */ - if (!maddr) { - int i; - - for (i = MAX_NUMNODES - 1; i >= 0; i--) { - if (i == nid || !node_online(i)) - continue; - maddr = gen_pool_alloc(uncached_pool[i], PAGE_SIZE); - dprintk(KERN_DEBUG "uncached_alloc_page alternate search " - "returns %lx on node %i\n", maddr, i); - if (maddr) { - break; - } - } - } + do { + if (!node_online(nid)) + continue; + pool = uncached_pool[nid]; + if (pool == NULL) + continue; + do { + uc_addr = gen_pool_alloc(pool, PAGE_SIZE); + if (uc_addr != 0) + return uc_addr; + } while (uncached_add_chunk(pool, nid) == 0); + + } while ((nid = (nid + 1) % MAX_NUMNODES) != starting_nid); - return maddr; + return 0; } EXPORT_SYMBOL(uncached_alloc_page); @@ -177,21 +190,22 @@ EXPORT_SYMBOL(uncached_alloc_page); /* * uncached_free_page * + * @uc_addr: uncached address of page to free + * * Free a single uncached page. */ -void -uncached_free_page(unsigned long maddr) +void uncached_free_page(unsigned long uc_addr) { - int node; - - node = paddr_to_nid(maddr - __IA64_UNCACHED_OFFSET); + int nid = paddr_to_nid(uc_addr - __IA64_UNCACHED_OFFSET); + struct gen_pool *pool = uncached_pool[nid]; - dprintk(KERN_DEBUG "uncached_free_page(%lx) on node %i\n", maddr, node); + if (unlikely(pool == NULL)) + return; - if ((maddr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET) - panic("uncached_free_page invalid address %lx\n", maddr); + if ((uc_addr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET) + panic("uncached_free_page invalid address %lx\n", uc_addr); - gen_pool_free(uncached_pool[node], maddr, PAGE_SIZE); + gen_pool_free(pool, uc_addr, PAGE_SIZE); } EXPORT_SYMBOL(uncached_free_page); @@ -199,43 +213,39 @@ EXPORT_SYMBOL(uncached_free_page); /* * uncached_build_memmap, * + * @uc_start: uncached starting address of a chunk of uncached memory + * @uc_end: uncached ending address of a chunk of uncached memory + * @arg: ignored, (NULL argument passed in on call to efi_memmap_walk_uc()) + * * Called at boot time to build a map of pages that can be used for * memory special operations. */ -static int __init -uncached_build_memmap(unsigned long start, unsigned long end, void *arg) +static int __init uncached_build_memmap(unsigned long uc_start, + unsigned long uc_end, void *arg) { - long length = end - start; - int node; - - dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end); + int nid = paddr_to_nid(uc_start - __IA64_UNCACHED_OFFSET); + struct gen_pool *pool = uncached_pool[nid]; + size_t size = uc_end - uc_start; touch_softlockup_watchdog(); - memset((char *)start, 0, length); - node = paddr_to_nid(start - __IA64_UNCACHED_OFFSET); - - for (; start < end ; start += PAGE_SIZE) { - dprintk(KERN_INFO "sticking %lx into the pool!\n", start); - gen_pool_free(uncached_pool[node], start, PAGE_SIZE); + if (pool != NULL) { + memset((char *)uc_start, 0, size); + (void) gen_pool_add(pool, uc_start, size, nid); } - return 0; } -static int __init uncached_init(void) { - int i; +static int __init uncached_init(void) +{ + int nid; - for (i = 0; i < MAX_NUMNODES; i++) { - if (!node_online(i)) - continue; - uncached_pool[i] = gen_pool_create(0, IA64_GRANULE_SHIFT, - &uncached_get_new_chunk, i); + for_each_online_node(nid) { + uncached_pool[nid] = gen_pool_create(PAGE_SHIFT, nid); } - efi_memmap_walk_uc(uncached_build_memmap); - + efi_memmap_walk_uc(uncached_build_memmap, NULL); return 0; } diff --git a/arch/ia64/sn/kernel/sn2/cache.c b/arch/ia64/sn/kernel/sn2/cache.c index bc3cfa17cd0..2862cb33026 100644 --- a/arch/ia64/sn/kernel/sn2/cache.c +++ b/arch/ia64/sn/kernel/sn2/cache.c @@ -3,11 +3,12 @@ * License. See the file "COPYING" in the main directory of this archive * for more details. * - * Copyright (C) 2001-2003 Silicon Graphics, Inc. All rights reserved. + * Copyright (C) 2001-2003, 2006 Silicon Graphics, Inc. All rights reserved. * */ #include #include +#include /** * sn_flush_all_caches - flush a range of address from all caches (incl. L4) @@ -17,18 +18,24 @@ * Flush a range of addresses from all caches including L4. * All addresses fully or partially contained within * @flush_addr to @flush_addr + @bytes are flushed - * from the all caches. + * from all caches. */ void sn_flush_all_caches(long flush_addr, long bytes) { - flush_icache_range(flush_addr, flush_addr+bytes); + unsigned long addr = flush_addr; + + /* SHub1 requires a cached address */ + if (is_shub1() && (addr & RGN_BITS) == RGN_BASE(RGN_UNCACHED)) + addr = (addr - RGN_BASE(RGN_UNCACHED)) + RGN_BASE(RGN_KERNEL); + + flush_icache_range(addr, addr + bytes); /* * The last call may have returned before the caches * were actually flushed, so we call it again to make * sure. */ - flush_icache_range(flush_addr, flush_addr+bytes); + flush_icache_range(addr, addr + bytes); mb(); } EXPORT_SYMBOL(sn_flush_all_caches); -- cgit v1.2.3