From: Mike Rapoport <rppt@xxxxxxxxxxxxx> commit 5e545df3292fbd3d5963c68980f1527ead2a2b3f upstream. ARM is the only architecture that defines CONFIG_ARCH_HAS_HOLES_MEMORYMODEL which in turn enables memmap_valid_within() function that is intended to verify existence of struct page associated with a pfn when there are holes in the memory map. However, the ARCH_HAS_HOLES_MEMORYMODEL also enables HAVE_ARCH_PFN_VALID and arch-specific pfn_valid() implementation that also deals with the holes in the memory map. The only two users of memmap_valid_within() call this function after a call to pfn_valid() so the memmap_valid_within() check becomes redundant. Remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL and memmap_valid_within() and rely entirely on ARM's implementation of pfn_valid() that is now enabled unconditionally. Link: https://lkml.kernel.org/r/20201101170454.9567-9-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Greg Ungerer <gerg@xxxxxxxxxxxxxx> Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Matt Turner <mattst88@xxxxxxxxx> Cc: Meelis Roos <mroos@xxxxxxxx> Cc: Michael Schmitz <schmitzmic@xxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Fixes: 8dd559d53b3b ("arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM") Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> --- Documentation/vm/memory-model.rst | 3 +-- arch/arm/Kconfig | 8 ++------ arch/arm/mach-bcm/Kconfig | 1 - arch/arm/mach-davinci/Kconfig | 1 - arch/arm/mach-exynos/Kconfig | 1 - arch/arm/mach-highbank/Kconfig | 1 - arch/arm/mach-omap2/Kconfig | 2 +- arch/arm/mach-s5pv210/Kconfig | 1 - arch/arm/mach-tango/Kconfig | 1 - fs/proc/kcore.c | 2 -- include/linux/mmzone.h | 31 ------------------------------- mm/mmzone.c | 14 -------------- mm/vmstat.c | 4 ---- 13 files changed, 4 insertions(+), 66 deletions(-) diff --git a/Documentation/vm/memory-model.rst b/Documentation/vm/memory-model.rst index 58a12376b7df..94db75ba7fbe 100644 --- a/Documentation/vm/memory-model.rst +++ b/Documentation/vm/memory-model.rst @@ -52,8 +52,7 @@ wrapper :c:func:`free_area_init`. Yet, the mappings array is not usable until the call to :c:func:`memblock_free_all` that hands all the memory to the page allocator. -If an architecture enables `CONFIG_ARCH_HAS_HOLES_MEMORYMODEL` option, -it may free parts of the `mem_map` array that do not cover the +An architecture may free parts of the `mem_map` array that do not cover the actual physical pages. In such case, the architecture specific :c:func:`pfn_valid` implementation should take the holes in the `mem_map` into account. diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4b36bbcf5a5b..a1622b9290fd 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -26,7 +26,7 @@ config ARM select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_CUSTOM_GPIO_H select ARCH_HAS_GCOV_PROFILE_ALL - select ARCH_KEEP_MEMBLOCK if HAVE_ARCH_PFN_VALID || KEXEC + select ARCH_KEEP_MEMBLOCK select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX @@ -521,7 +521,6 @@ config ARCH_S3C24XX config ARCH_OMAP1 bool "TI OMAP1" depends on MMU - select ARCH_HAS_HOLES_MEMORYMODEL select ARCH_OMAP select CLKDEV_LOOKUP select CLKSRC_MMIO @@ -1518,9 +1517,6 @@ config OABI_COMPAT UNPREDICTABLE (in fact it can be predicted that it won't work at all). If in doubt say N. -config ARCH_HAS_HOLES_MEMORYMODEL - bool - config ARCH_SPARSEMEM_ENABLE bool @@ -1528,7 +1524,7 @@ config ARCH_SPARSEMEM_DEFAULT def_bool ARCH_SPARSEMEM_ENABLE config HAVE_ARCH_PFN_VALID - def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM + def_bool y config HIGHMEM bool "High Memory Support" diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig index 5e5f1fabc3d4..634d1bc3c011 100644 --- a/arch/arm/mach-bcm/Kconfig +++ b/arch/arm/mach-bcm/Kconfig @@ -214,7 +214,6 @@ config ARCH_BRCMSTB select HAVE_ARM_ARCH_TIMER select BRCMSTB_L2_IRQ select BCM7120_L2_IRQ - select ARCH_HAS_HOLES_MEMORYMODEL select ZONE_DMA if ARM_LPAE select SOC_BRCMSTB select SOC_BUS diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig index 02b180ad7245..4d3b7d0418c4 100644 --- a/arch/arm/mach-davinci/Kconfig +++ b/arch/arm/mach-davinci/Kconfig @@ -5,7 +5,6 @@ menuconfig ARCH_DAVINCI depends on ARCH_MULTI_V5 select DAVINCI_TIMER select ZONE_DMA - select ARCH_HAS_HOLES_MEMORYMODEL select PM_GENERIC_DOMAINS if PM select PM_GENERIC_DOMAINS_OF if PM && OF select REGMAP_MMIO diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig index 9dab1f50a02f..fc01137628e4 100644 --- a/arch/arm/mach-exynos/Kconfig +++ b/arch/arm/mach-exynos/Kconfig @@ -8,7 +8,6 @@ menuconfig ARCH_EXYNOS bool "Samsung EXYNOS" depends on ARCH_MULTI_V7 - select ARCH_HAS_HOLES_MEMORYMODEL select ARCH_SUPPORTS_BIG_ENDIAN select ARM_AMBA select ARM_GIC diff --git a/arch/arm/mach-highbank/Kconfig b/arch/arm/mach-highbank/Kconfig index 1bc68913d62c..9de38ce8124f 100644 --- a/arch/arm/mach-highbank/Kconfig +++ b/arch/arm/mach-highbank/Kconfig @@ -2,7 +2,6 @@ config ARCH_HIGHBANK bool "Calxeda ECX-1000/2000 (Highbank/Midway)" depends on ARCH_MULTI_V7 - select ARCH_HAS_HOLES_MEMORYMODEL select ARCH_SUPPORTS_BIG_ENDIAN select ARM_AMBA select ARM_ERRATA_764369 if SMP diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index fdb6743760a2..0211f4aa8cc7 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -94,7 +94,7 @@ config SOC_DRA7XX config ARCH_OMAP2PLUS bool select ARCH_HAS_BANDGAP - select ARCH_HAS_HOLES_MEMORYMODEL + select ARCH_HAS_RESET_CONTROLLER select ARCH_OMAP select CLKSRC_MMIO select GENERIC_IRQ_CHIP diff --git a/arch/arm/mach-s5pv210/Kconfig b/arch/arm/mach-s5pv210/Kconfig index 03984a791879..69ff1bb89f38 100644 --- a/arch/arm/mach-s5pv210/Kconfig +++ b/arch/arm/mach-s5pv210/Kconfig @@ -8,7 +8,6 @@ config ARCH_S5PV210 bool "Samsung S5PV210/S5PC110" depends on ARCH_MULTI_V7 - select ARCH_HAS_HOLES_MEMORYMODEL select ARM_VIC select CLKSRC_SAMSUNG_PWM select COMMON_CLK_SAMSUNG diff --git a/arch/arm/mach-tango/Kconfig b/arch/arm/mach-tango/Kconfig index 25b2fd434861..a9eeda36aeb1 100644 --- a/arch/arm/mach-tango/Kconfig +++ b/arch/arm/mach-tango/Kconfig @@ -3,7 +3,6 @@ config ARCH_TANGO bool "Sigma Designs Tango4 (SMP87xx)" depends on ARCH_MULTI_V7 # Cortex-A9 MPCore r3p0, PL310 r3p2 - select ARCH_HAS_HOLES_MEMORYMODEL select ARM_ERRATA_754322 select ARM_ERRATA_764369 if SMP select ARM_ERRATA_775420 diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index e2ed8e08cc7a..d1cabccc02b7 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -193,8 +193,6 @@ kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg) return 1; p = pfn_to_page(pfn); - if (!memmap_valid_within(pfn, p, page_zone(p))) - return 1; ent = kmalloc(sizeof(*ent), GFP_KERNEL); if (!ent) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index e4f9df955040..b138ddad619e 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1438,37 +1438,6 @@ void memory_present(int nid, unsigned long start, unsigned long end); #define pfn_valid_within(pfn) (1) #endif -#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL -/* - * pfn_valid() is meant to be able to tell if a given PFN has valid memmap - * associated with it or not. This means that a struct page exists for this - * pfn. The caller cannot assume the page is fully initialized in general. - * Hotplugable pages might not have been onlined yet. pfn_to_online_page() - * will ensure the struct page is fully online and initialized. Special pages - * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly. - * - * In FLATMEM, it is expected that holes always have valid memmap as long as - * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed - * that a valid section has a memmap for the entire section. - * - * However, an ARM, and maybe other embedded architectures in the future - * free memmap backing holes to save memory on the assumption the memmap is - * never used. The page_zone linkages are then broken even though pfn_valid() - * returns true. A walker of the full memmap must then do this additional - * check to ensure the memmap they are looking at is sane by making sure - * the zone and PFN linkages are still valid. This is expensive, but walkers - * of the full memmap are extremely rare. - */ -bool memmap_valid_within(unsigned long pfn, - struct page *page, struct zone *zone); -#else -static inline bool memmap_valid_within(unsigned long pfn, - struct page *page, struct zone *zone) -{ - return true; -} -#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ - #endif /* !__GENERATING_BOUNDS.H */ #endif /* !__ASSEMBLY__ */ #endif /* _LINUX_MMZONE_H */ diff --git a/mm/mmzone.c b/mm/mmzone.c index 4686fdc23bb9..f337831affc2 100644 --- a/mm/mmzone.c +++ b/mm/mmzone.c @@ -72,20 +72,6 @@ struct zoneref *__next_zones_zonelist(struct zoneref *z, return z; } -#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL -bool memmap_valid_within(unsigned long pfn, - struct page *page, struct zone *zone) -{ - if (page_to_pfn(page) != pfn) - return false; - - if (page_zone(page) != zone) - return false; - - return true; -} -#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ - void lruvec_init(struct lruvec *lruvec) { enum lru_list lru; diff --git a/mm/vmstat.c b/mm/vmstat.c index a8222041bd44..240fe2153ca9 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1444,10 +1444,6 @@ static void pagetypeinfo_showblockcount_print(struct seq_file *m, if (!page) continue; - /* Watch for unexpected holes punched in the memmap */ - if (!memmap_valid_within(pfn, page, zone)) - continue; - if (page_zone(page) != zone) continue; -- 2.34.1
