--- /dev/null
+From 5e545df3292fbd3d5963c68980f1527ead2a2b3f Mon Sep 17 00:00:00 2001
+From: Mike Rapoport <rppt@linux.ibm.com>
+Date: Mon, 14 Dec 2020 19:09:55 -0800
+Subject: arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
+
+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>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ 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(-)
+
+--- a/Documentation/vm/memory-model.rst
++++ b/Documentation/vm/memory-model.rst
+@@ -51,8 +51,7 @@ call :c:func:`free_area_init` function.
+ 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.
+--- 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"
+--- 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
+--- 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
+--- 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
+--- 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
+--- 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
+--- 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
+--- 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
+--- a/fs/proc/kcore.c
++++ b/fs/proc/kcore.c
+@@ -193,8 +193,6 @@ kclist_add_private(unsigned long pfn, un
+ 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)
+--- 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 */
+--- a/mm/mmzone.c
++++ b/mm/mmzone.c
+@@ -72,20 +72,6 @@ struct zoneref *__next_zones_zonelist(st
+ 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;
+--- a/mm/vmstat.c
++++ b/mm/vmstat.c
+@@ -1503,10 +1503,6 @@ static void pagetypeinfo_showblockcount_
+ 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;
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
