From: Mike Rapoport rppt@linux.ibm.com

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@kernel.org Signed-off-by: Mike Rapoport rppt@linux.ibm.com Cc: Alexey Dobriyan adobriyan@gmail.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Geert Uytterhoeven geert@linux-m68k.org Cc: Greg Ungerer gerg@linux-m68k.org Cc: John Paul Adrian Glaubitz glaubitz@physik.fu-berlin.de Cc: Jonathan Corbet corbet@lwn.net Cc: Matt Turner mattst88@gmail.com Cc: Meelis Roos mroos@linux.ee Cc: Michael Schmitz schmitzmic@gmail.com Cc: Russell King linux@armlinux.org.uk Cc: Tony Luck tony.luck@intel.com Cc: Vineet Gupta vgupta@synopsys.com Cc: Will Deacon will@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Reported-by: kernel test robot lkp@intel.com Fixes: 8dd559d53b3b ("arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM") Signed-off-by: Mike Rapoport rppt@linux.ibm.com --- 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 | 1 - 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, 3 insertions(+), 66 deletions(-)

diff --git a/Documentation/vm/memory-model.rst b/Documentation/vm/memory-model.rst index 9daadf9faba1..ce398a7dc6cd 100644 --- a/Documentation/vm/memory-model.rst +++ b/Documentation/vm/memory-model.rst @@ -51,8 +51,7 @@ call :c:func:`free_area_init` function. 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 a0eac00e2c81..b587ecc6f949 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -25,7 +25,7 @@ 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 @@ -1481,9 +1480,6 @@ 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_SELECT_MEMORY_MODEL bool

@@ -1495,7 +1491,7 @@ config ARCH_SPARSEMEM_ENABLE select SPARSEMEM_STATIC if SPARSEMEM

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 ae790908fc74..9b594ae98153 100644 --- a/arch/arm/mach-bcm/Kconfig +++ b/arch/arm/mach-bcm/Kconfig @@ -211,7 +211,6 @@ config ARCH_BRCMSTB select BCM7038_L1_IRQ 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 f56ff8c24043..de11030748d0 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 56314b1c7408..b5df98ee5d17 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 3f62a0c9450d..164985505f9e 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -93,7 +93,6 @@ 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 diff --git a/arch/arm/mach-s5pv210/Kconfig b/arch/arm/mach-s5pv210/Kconfig index 95d4e8284866..d644b45bc29d 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 e502414b3556..4d2e64e9016c 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 f3016b8e698a..b2e4599b8883 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1443,37 +1443,6 @@ struct mminit_pfnnid_cache { #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 698bc0bc18d1..e292e63afebf 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1503,10 +1503,6 @@ 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;