From 908eedc6168bd92e89f90d89fa389065a36358fa Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 22 Sep 2009 16:45:46 -0700 Subject: [PATCH] walk system ram range MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Originally, walk_memory_resource() was introduced to traverse all memory of "System RAM" for detecting memory hotplug/unplug range. For doing so, flags of IORESOUCE_MEM|IORESOURCE_BUSY was used and this was enough for memory hotplug. But for using other purpose, /proc/kcore, this may includes some firmware area marked as IORESOURCE_BUSY | IORESOUCE_MEM. This patch makes the check strict to find out busy "System RAM". Note: PPC64 keeps their own walk_memory_resouce(), which walk through ppc64's lmb informaton. Because old kclist_add() is called per lmb, this patch makes no difference in behavior, finally. And this patch removes CONFIG_MEMORY_HOTPLUG check from this function. Because pfn_valid() just show "there is memmap or not* and cannot be used for "there is physical memory or not", this function is useful in generic to scan physical memory range. Signed-off-by: KAMEZAWA Hiroyuki Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: WANG Cong Cc: Américo Wang Cc: David Rientjes Cc: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/mm/mem.c | 6 +++--- drivers/infiniband/hw/ehca/ehca_mrmw.c | 2 +- drivers/net/ehea/ehea_qmr.c | 2 +- include/linux/ioport.h | 4 ++++ include/linux/memory_hotplug.h | 8 -------- kernel/resource.c | 23 ++++++++++++++++------- mm/memory_hotplug.c | 6 +++--- 7 files changed, 28 insertions(+), 23 deletions(-) diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 0e5c59b995ef..59736317bf0e 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -143,8 +143,8 @@ int arch_add_memory(int nid, u64 start, u64 size) * memory regions, find holes and callback for contiguous regions. */ int -walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, - int (*func)(unsigned long, unsigned long, void *)) +walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg, int (*func)(unsigned long, unsigned long, void *)) { struct lmb_property res; unsigned long pfn, len; @@ -166,7 +166,7 @@ walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, } return ret; } -EXPORT_SYMBOL_GPL(walk_memory_resource); +EXPORT_SYMBOL_GPL(walk_system_ram_range); /* * Initialize the bootmem system and give it all the memory we diff --git a/drivers/infiniband/hw/ehca/ehca_mrmw.c b/drivers/infiniband/hw/ehca/ehca_mrmw.c index 7663a2a9f130..7550a534005c 100644 --- a/drivers/infiniband/hw/ehca/ehca_mrmw.c +++ b/drivers/infiniband/hw/ehca/ehca_mrmw.c @@ -2463,7 +2463,7 @@ int ehca_create_busmap(void) int ret; ehca_mr_len = 0; - ret = walk_memory_resource(0, 1ULL << MAX_PHYSMEM_BITS, NULL, + ret = walk_system_ram_range(0, 1ULL << MAX_PHYSMEM_BITS, NULL, ehca_create_busmap_callback); return ret; } diff --git a/drivers/net/ehea/ehea_qmr.c b/drivers/net/ehea/ehea_qmr.c index 3747457f5e69..bc7c5b7abb88 100644 --- a/drivers/net/ehea/ehea_qmr.c +++ b/drivers/net/ehea/ehea_qmr.c @@ -751,7 +751,7 @@ int ehea_create_busmap(void) mutex_lock(&ehea_busmap_mutex); ehea_mr_len = 0; - ret = walk_memory_resource(0, 1ULL << MAX_PHYSMEM_BITS, NULL, + ret = walk_system_ram_range(0, 1ULL << MAX_PHYSMEM_BITS, NULL, ehea_create_busmap_callback); mutex_unlock(&ehea_busmap_mutex); return ret; diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 786e7b8cece9..83aa81297ea3 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -184,5 +184,9 @@ extern void __devm_release_region(struct device *dev, struct resource *parent, extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size); extern int iomem_is_exclusive(u64 addr); +extern int +walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg, int (*func)(unsigned long, unsigned long, void *)); + #endif /* __ASSEMBLY__ */ #endif /* _LINUX_IOPORT_H */ diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index d95f72e79b82..fed969281a41 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -191,14 +191,6 @@ static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) #endif /* ! CONFIG_MEMORY_HOTPLUG */ -/* - * Walk through all memory which is registered as resource. - * arg is (start_pfn, nr_pages, private_arg_pointer) - */ -extern int walk_memory_resource(unsigned long start_pfn, - unsigned long nr_pages, void *arg, - int (*func)(unsigned long, unsigned long, void *)); - #ifdef CONFIG_MEMORY_HOTREMOVE extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages); diff --git a/kernel/resource.c b/kernel/resource.c index 78b087221c15..fb11a58b9594 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -223,13 +223,13 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); -#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY) +#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) /* * Finds the lowest memory reosurce exists within [res->start.res->end) - * the caller must specify res->start, res->end, res->flags. + * the caller must specify res->start, res->end, res->flags and "name". * If found, returns 0, res is overwritten, if not found, returns -1. */ -static int find_next_system_ram(struct resource *res) +static int find_next_system_ram(struct resource *res, char *name) { resource_size_t start, end; struct resource *p; @@ -245,6 +245,8 @@ static int find_next_system_ram(struct resource *res) /* system ram is just marked as IORESOURCE_MEM */ if (p->flags != res->flags) continue; + if (name && strcmp(p->name, name)) + continue; if (p->start > end) { p = NULL; break; @@ -262,19 +264,26 @@ static int find_next_system_ram(struct resource *res) res->end = p->end; return 0; } -int -walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, - int (*func)(unsigned long, unsigned long, void *)) + +/* + * This function calls callback against all memory range of "System RAM" + * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. + * Now, this function is only for "System RAM". + */ +int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg, int (*func)(unsigned long, unsigned long, void *)) { struct resource res; unsigned long pfn, len; u64 orig_end; int ret = -1; + res.start = (u64) start_pfn << PAGE_SHIFT; res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; orig_end = res.end; - while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) { + while ((res.start < res.end) && + (find_next_system_ram(&res, "System RAM") >= 0)) { pfn = (unsigned long)(res.start >> PAGE_SHIFT); len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT); ret = (*func)(pfn, len, arg); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index efe3e0ec2e61..821dee596377 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -413,7 +413,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages) if (!populated_zone(zone)) need_zonelists_rebuild = 1; - ret = walk_memory_resource(pfn, nr_pages, &onlined_pages, + ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, online_pages_range); if (ret) { printk(KERN_DEBUG "online_pages %lx at %lx failed\n", @@ -705,7 +705,7 @@ offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, static void offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) { - walk_memory_resource(start_pfn, end_pfn - start_pfn, NULL, + walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, offline_isolated_pages_cb); } @@ -731,7 +731,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) long offlined = 0; int ret; - ret = walk_memory_resource(start_pfn, end_pfn - start_pfn, &offlined, + ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, check_pages_isolated_cb); if (ret < 0) offlined = (long)ret;