From a99824f327c748b2753f4fa570eb1fefcd6a9c4d Mon Sep 17 00:00:00 2001 From: Badari Pulavarty Date: Tue, 5 Feb 2008 00:10:18 -0800 Subject: [PATCH] [POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc walk_memory_resource() verifies if there are holes in a given memory range, by checking against /proc/iomem. On x86/ia64 system memory is represented in /proc/iomem. On powerpc, we don't show system memory as IO resource in /proc/iomem - instead it's maintained in /proc/device-tree. This provides a way for an architecture to provide its own walk_memory_resource() function. On powerpc, the memory region is small (16MB), contiguous and non-overlapping. So extra checking against the device-tree is not needed. Signed-off-by: Badari Pulavarty Acked-by: KAMEZAWA Hiroyuki Cc: Dave Hansen Cc: Benjamin Herrenschmidt Cc: Kumar Gala Signed-off-by: Andrew Morton Signed-off-by: Paul Mackerras --- arch/powerpc/Kconfig | 3 +++ arch/powerpc/mm/mem.c | 17 +++++++++++++++++ kernel/resource.c | 2 +- 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index d55063c021d5..26b963c33c88 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -272,6 +272,9 @@ config HOTPLUG_CPU config ARCH_ENABLE_MEMORY_HOTPLUG def_bool y +config ARCH_HAS_WALK_MEMORY + def_bool y + config ARCH_ENABLE_MEMORY_HOTREMOVE def_bool y diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index f0a1fd268b7a..be5c506779a7 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -145,6 +145,23 @@ out: return ret; } #endif /* CONFIG_MEMORY_HOTREMOVE */ + +/* + * walk_memory_resource() needs to make sure there is no holes in a given + * memory range. On PPC64, since this range comes from /sysfs, the range + * is guaranteed to be valid, non-overlapping and can not contain any + * holes. By the time we get here (memory add or remove), /proc/device-tree + * is updated and correct. Only reason we need to check against device-tree + * would be if we allow user-land to specify a memory range through a + * system call/ioctl etc. instead of doing offline/online through /sysfs. + */ +int +walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, + int (*func)(unsigned long, unsigned long, void *)) +{ + return (*func)(start_pfn, nr_pages, arg); +} + #endif /* CONFIG_MEMORY_HOTPLUG */ void show_mem(void) diff --git a/kernel/resource.c b/kernel/resource.c index 2eb553d9b517..82aea814d409 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -228,7 +228,7 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); -#ifdef CONFIG_MEMORY_HOTPLUG +#if defined(CONFIG_MEMORY_HOTPLUG) && !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. -- 2.20.1