arch, mm: set max_mapnr when allocating memory map for FLATMEM

max_mapnr is essentially the size of the memory map for systems that use
FLATMEM. There is no reason to calculate it in each and every architecture
when it's anyway calculated in alloc_node_mem_map().

Drop setting of max_mapnr from architecture code and set it once in
alloc_node_mem_map().

While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so
there won't be two copies for MMU and !MMU variants.

Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>	[x86]
Tested-by: Mark Brown <broonie@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Guo Ren (csky) <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index 61c2198b1359cf81190b934c54a21b8de60d02e7..ec0eeae9c653d85f9fb256a53e409f7c509e0f5a 100644 (file)
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -276,7 +276,6 @@ srm_paging_stop (void)
 void __init
 mem_init(void)
 {
-       set_max_mapnr(max_low_pfn);
        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
        memblock_free_all();
 }

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 6a71b23f1383cbcf04882f129f50de98efddb0f8..7ef883d58dc17226965c13530e7cdec5bb27b30a 100644 (file)
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -154,11 +154,6 @@ void __init setup_arch_memory(void)
 
        arch_pfn_offset = min(min_low_pfn, min_high_pfn);
        kmap_init();
-
-#else /* CONFIG_HIGHMEM */
-       /* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */
-       max_mapnr = max_low_pfn - min_low_pfn;
-
 #endif /* CONFIG_HIGHMEM */
 
        free_area_init(max_zone_pfn);

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 9aec1cb2386fe109c2fa84fc5180acc604e132cc..d4bcc745a044547bfbc46ed26784cbd0ea6afba9 100644 (file)
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -275,8 +275,6 @@ void __init mem_init(void)
        swiotlb_init(max_pfn > arm_dma_pfn_limit, SWIOTLB_VERBOSE);
 #endif
 
-       set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
-
 #ifdef CONFIG_SA1111
        /* now that our DMA memory is actually so designated, we can free it */
        memblock_phys_free(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET);

diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
index ab51acbc19b2467c13c6361359a4ea5d8e024e54..ba6694d6170a0dc2e12c19aca3f76e6106a8003b 100644 (file)
--- a/arch/csky/mm/init.c
+++ b/arch/csky/mm/init.c
@@ -46,10 +46,6 @@ void __init mem_init(void)
 {
 #ifdef CONFIG_HIGHMEM
        unsigned long tmp;
-
-       set_max_mapnr(highend_pfn - ARCH_PFN_OFFSET);
-#else
-       set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
 #endif
        high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 

diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
index ca5aa5f46a9fe52e6400a4d87dff7f125b750bba..00449df50db102d3d20318c9686288f0167fe32d 100644 (file)
--- a/arch/loongarch/mm/init.c
+++ b/arch/loongarch/mm/init.c
@@ -78,7 +78,6 @@ void __init paging_init(void)
 
 void __init mem_init(void)
 {
-       max_mapnr = max_low_pfn;
        high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 
        memblock_free_all();

diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 4520c57415797fa729107799b13d7f3fee866095..857cd2b44bcfedc742dfd110f4ac138b9d0c942f 100644 (file)
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -104,17 +104,13 @@ void __init setup_memory(void)
         *
         * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
         * max_low_pfn
-        * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
         */
 
        /* memory start is from the kernel end (aligned) to higher addr */
        min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
-       /* RAM is assumed contiguous */
-       max_mapnr = memory_size >> PAGE_SHIFT;
        max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
        max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
 
-       pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
        pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
        pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
        pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 820e35a59d4d0fb970104a13d4b930fd889a8833..eb61a73520a0428b633a83477f2b6b466b50847c 100644 (file)
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -415,15 +415,7 @@ void __init paging_init(void)
                       " %ldk highmem ignored\n",
                       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
                max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
-
-               max_mapnr = max_low_pfn;
-       } else if (highend_pfn) {
-               max_mapnr = highend_pfn;
-       } else {
-               max_mapnr = max_low_pfn;
        }
-#else
-       max_mapnr = max_low_pfn;
 #endif
        high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 

diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c
index a4cffbfc13999870e6ebae742c7c7e43e58cd85b..2a40150142c36f2a6645dc25284415ddbd59dfae 100644 (file)
--- a/arch/nios2/kernel/setup.c
+++ b/arch/nios2/kernel/setup.c
@@ -158,7 +158,6 @@ void __init setup_arch(char **cmdline_p)
        *cmdline_p = boot_command_line;
 
        find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
-       max_mapnr = max_low_pfn;
 
        memblock_reserve(__pa_symbol(_stext), _end - _stext);
 #ifdef CONFIG_BLK_DEV_INITRD

diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
index aa692ad30044bbdbe3ea6bb28d48653df3a15a8b..3cafa87ead9e6cedace4cee4c83bfe6528e0e81d 100644 (file)
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c
@@ -51,7 +51,7 @@ void __init paging_init(void)
        pagetable_init();
        pgd_current = swapper_pg_dir;
 
-       max_zone_pfn[ZONE_NORMAL] = max_mapnr;
+       max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
 
        /* pass the memory from the bootmem allocator to the main allocator */
        free_area_init(max_zone_pfn);

diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index d0cb1a0126f95d05c9113ff08a7f5536b4432801..9093c336e158a7304a00082ee4be7009d77bcc61 100644 (file)
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -193,7 +193,6 @@ void __init mem_init(void)
 {
        BUG_ON(!mem_map);
 
-       max_mapnr = max_low_pfn;
        high_memory = (void *)__va(max_low_pfn * PAGE_SIZE);
 
        /* clear the zero-page */

diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 61c0a24770726f277ee9f2578d8e2b2e525bcb30..2cdfc0b1195cac182b34a78cdebd54275b7dc7d9 100644 (file)
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -563,7 +563,6 @@ void __init mem_init(void)
 #endif
 
        high_memory = __va((max_pfn << PAGE_SHIFT));
-       set_max_mapnr(max_low_pfn);
        memblock_free_all();
 
 #ifdef CONFIG_PA11

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index a08b0ede4e64bdfe512dcba09de616b63e5241a4..68d47c53876c6b5d6ddb15031434caa0ab7658aa 100644 (file)
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -957,8 +957,6 @@ void __init setup_arch(char **cmdline_p)
 
        /* Parse memory topology */
        mem_topology_setup();
-       /* Set max_mapnr before paging_init() */
-       set_max_mapnr(max_pfn);
        high_memory = (void *)__va(max_low_pfn * PAGE_SIZE);
 
        /*

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 15b2eda4c364b39261f94c371d791a24fb929aeb..157c9ca51541125dc1f291a7cde29d3b342ade69 100644 (file)
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -298,7 +298,6 @@ static void __init setup_bootmem(void)
        high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
 
        dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
-       set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
 
        reserve_initrd_mem();
 

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 2b41dc9b1fa3421d2b6c9cf9f735916d23b8b833..ad567e2100b74be368107dbc7fb0c0aa07a4526c 100644 (file)
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -159,7 +159,6 @@ void __init mem_init(void)
        cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
        cpumask_set_cpu(0, mm_cpumask(&init_mm));
 
-       set_max_mapnr(max_low_pfn);
         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 
        pv_init();

diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 289a2fecebef98d2fb5aa44bcae4feead7985079..72aea5cd1b856453b3c6bda0655e2621f4de5ce5 100644 (file)
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -290,7 +290,6 @@ void __init paging_init(void)
         */
        max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
        min_low_pfn = __MEMORY_START >> PAGE_SHIFT;
-       set_max_mapnr(max_low_pfn - min_low_pfn);
 
        nodes_clear(node_online_map);
 

diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index d96a14ffceebf5a509dc1bc8c173f18c714f42bd..6b58da14edc6b7ae121839e57e9f3ec5761d25e9 100644 (file)
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -275,7 +275,6 @@ void __init mem_init(void)
 
        taint_real_pages();
 
-       max_mapnr = last_valid_pfn - pfn_base;
        high_memory = __va(max_low_pfn << PAGE_SHIFT);
        memblock_free_all();
 

diff --git a/arch/um/include/shared/mem_user.h b/arch/um/include/shared/mem_user.h
index adfa08062f88e725f2d11645f2d35bf79191f3d8..d4727efcf23d065b0bdfbb522644ddeeb4acbe08 100644 (file)
--- a/arch/um/include/shared/mem_user.h
+++ b/arch/um/include/shared/mem_user.h
@@ -47,7 +47,6 @@ extern int iomem_size;
 #define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))
 
 extern unsigned long find_iomem(char *driver, unsigned long *len_out);
-extern void mem_total_pages(unsigned long physmem, unsigned long iomem);
 extern void setup_physmem(unsigned long start, unsigned long usable,
                          unsigned long len);
 extern void map_memory(unsigned long virt, unsigned long phys,

diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index a74f17b033c4175c4c68081ad0dbcd8fe493d609..af02b5f9911d343b3089f40aea3d6d595b47f7f4 100644 (file)
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -22,18 +22,6 @@ static int physmem_fd = -1;
 unsigned long high_physmem;
 EXPORT_SYMBOL(high_physmem);
 
-void __init mem_total_pages(unsigned long physmem, unsigned long iomem)
-{
-       unsigned long phys_pages, iomem_pages, total_pages;
-
-       phys_pages  = physmem >> PAGE_SHIFT;
-       iomem_pages = iomem   >> PAGE_SHIFT;
-
-       total_pages = phys_pages + iomem_pages;
-
-       max_mapnr = total_pages;
-}
-
 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
                int r, int w, int x)
 {

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 79ea97d4797ecc9c157ee948ae0505bcdef84da5..6414cbf005727b004e30b4b7be1f8b365f157f8f 100644 (file)
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -419,7 +419,6 @@ void __init setup_arch(char **cmdline_p)
 
        stack_protections((unsigned long) init_task.stack);
        setup_physmem(uml_physmem, uml_reserved, physmem_size);
-       mem_total_pages(physmem_size, iomem_size);
        uml_dtb_init();
        read_initrd();
 

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index ac41b1e0940d47ca647dc2006c40b6005c2dae4f..6d2f8cb9451edb538330abb0bbe207a41dcf09ae 100644 (file)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -650,9 +650,6 @@ void __init initmem_init(void)
 
        memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 
-#ifdef CONFIG_FLATMEM
-       max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
-#endif
        __vmalloc_start_set = true;
 
        printk(KERN_NOTICE "%ldMB LOWMEM available.\n",

diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 01577d33e602a8bc6b55893125b38f4d5cf39ab0..9f1b0d5fccc776f204dfd6e2bfabd598501c88fa 100644 (file)
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -164,7 +164,6 @@ void __init mem_init(void)
 {
        free_highpages();
 
-       max_mapnr = max_pfn - ARCH_PFN_OFFSET;
        high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
 
        memblock_free_all();

diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h
index 6d1fb6162ac1a6b20c1854d938272e1c850c9b08..a3b5029aebbdc1435fbc9bbea88a2a290526877b 100644 (file)
--- a/include/asm-generic/memory_model.h
+++ b/include/asm-generic/memory_model.h
@@ -19,11 +19,12 @@
 #define __page_to_pfn(page)    ((unsigned long)((page) - mem_map) + \
                                 ARCH_PFN_OFFSET)
 
+/* avoid <linux/mm.h> include hell */
+extern unsigned long max_mapnr;
+
 #ifndef pfn_valid
 static inline int pfn_valid(unsigned long pfn)
 {
-       /* avoid <linux/mm.h> include hell */
-       extern unsigned long max_mapnr;
        unsigned long pfn_offset = ARCH_PFN_OFFSET;
 
        return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 82776b40939181b4c098bb459ebf3951668ab146..8c4cb8c28507e291ba1cadabff9e4bbebf7c8de2 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -46,17 +46,6 @@ extern int sysctl_page_lock_unfairness;
 void mm_core_init(void);
 void init_mm_internals(void);
 
-#ifndef CONFIG_NUMA            /* Don't use mapnrs, do it properly */
-extern unsigned long max_mapnr;
-
-static inline void set_max_mapnr(unsigned long limit)
-{
-       max_mapnr = limit;
-}
-#else
-static inline void set_max_mapnr(unsigned long limit) { }
-#endif
-
 extern atomic_long_t _totalram_pages;
 static inline unsigned long totalram_pages(void)
 {

diff --git a/mm/memory.c b/mm/memory.c
index 8873b7a4962ca164dc31538e0589d64cb271591a..a1d7664855f2518df53737c62f4e6b7faec05a9a 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -95,14 +95,6 @@
 #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid.
 #endif
 
-#ifndef CONFIG_NUMA
-unsigned long max_mapnr;
-EXPORT_SYMBOL(max_mapnr);
-
-struct page *mem_map;
-EXPORT_SYMBOL(mem_map);
-#endif
-
 static vm_fault_t do_fault(struct vm_fault *vmf);
 static vm_fault_t do_anonymous_page(struct vm_fault *vmf);
 static bool vmf_pte_changed(struct vm_fault *vmf);

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 133640a93d1da8f0290d55f435cac6ae4fd5e28d..7fd48d2d5064ca23c0f9877ab2691e8543a65b2e 100644 (file)
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -37,6 +37,14 @@
 
 #include <asm/setup.h>
 
+#ifndef CONFIG_NUMA
+unsigned long max_mapnr;
+EXPORT_SYMBOL(max_mapnr);
+
+struct page *mem_map;
+EXPORT_SYMBOL(mem_map);
+#endif
+
 #ifdef CONFIG_DEBUG_MEMORY_INIT
 int __meminitdata mminit_loglevel;
 
@@ -1639,7 +1647,7 @@ static void __init alloc_node_mem_map(struct pglist_data *pgdat)
        start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
        offset = pgdat->node_start_pfn - start;
        /*
-                * The zone's endpoints aren't required to be MAX_PAGE_ORDER
+        * The zone's endpoints aren't required to be MAX_PAGE_ORDER
         * aligned but the node_mem_map endpoints must be in order
         * for the buddy allocator to function correctly.
         */
@@ -1655,14 +1663,15 @@ static void __init alloc_node_mem_map(struct pglist_data *pgdat)
        pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
                 __func__, pgdat->node_id, (unsigned long)pgdat,
                 (unsigned long)pgdat->node_mem_map);
-#ifndef CONFIG_NUMA
+
        /* the global mem_map is just set as node 0's */
-       if (pgdat == NODE_DATA(0)) {
-               mem_map = NODE_DATA(0)->node_mem_map;
-               if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
-                       mem_map -= offset;
-       }
-#endif
+       WARN_ON(pgdat != NODE_DATA(0));
+
+       mem_map = pgdat->node_mem_map;
+       if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
+               mem_map -= offset;
+
+       max_mapnr = end - start;
 }
 #else
 static inline void alloc_node_mem_map(struct pglist_data *pgdat) { }

diff --git a/mm/nommu.c b/mm/nommu.c
index 8b31d8396297e547f6dc28e8a0cfc2db0778ae35..43751726f977d7c2f01f9b0e703232a600b0a65f 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -44,16 +44,12 @@
 
 void *high_memory;
 EXPORT_SYMBOL(high_memory);
-struct page *mem_map;
-unsigned long max_mapnr;
-EXPORT_SYMBOL(max_mapnr);
 unsigned long highest_memmap_pfn;
 int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
 int heap_stack_gap = 0;
 
 atomic_long_t mmap_pages_allocated;
 
-EXPORT_SYMBOL(mem_map);
 
 /* list of mapped, potentially shareable regions */
 static struct kmem_cache *vm_region_jar;