[PATCH 10/13] arch, mm: set high_memory in free_area_init()
From: Mike Rapoport <rppt@kernel.org>
Date: 2025-03-06 18:53:56
Also in:
linux-alpha, linux-arch, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, linux-um, lkml, loongarch, sparclinux
Subsystem:
alpha port, arm port, arm64 port (aarch64 architecture), c-sky architecture, linux for powerpc (32-bit and 64-bit), loongarch, m68k architecture, memblock and memory management initialization, memory management, memory management - core, memory mapping, microblaze architecture, mips, nios2 architecture, openrisc architecture, parisc architecture, qualcomm hexagon architecture, risc-v architecture, s390 architecture, sparc + ultrasparc (sparc/sparc64), superh, synopsys arc architecture, tensilica xtensa port (xtensa), the rest, user-mode linux (uml), x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Russell King, Catalin Marinas, Will Deacon, Guo Ren, Madhavan Srinivasan, Michael Ellerman, Huacai Chen, Geert Uytterhoeven, Mike Rapoport, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Michal Simek, Thomas Bogendoerfer, Dinh Nguyen, Simon Schuster, Jonas Bonn, Stefan Kristiansson, Stafford Horne, "James E.J. Bottomley", Helge Deller, Brian Cain, Paul Walmsley, Palmer Dabbelt, Albert Ou, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, "David S. Miller", Andreas Larsson, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Vineet Gupta, Chris Zankel, Max Filippov, Linus Torvalds, Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
From: "Mike Rapoport (Microsoft)" <rppt@kernel.org> high_memory defines upper bound on the directly mapped memory. This bound is defined by the beginning of ZONE_HIGHMEM when a system has high memory and by the end of memory otherwise. All this is known to generic memory management initialization code that can set high_memory while initializing core mm structures. Remove per-architecture calculation of high_memory and add a generic version to free_area_init(). Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> --- arch/alpha/mm/init.c | 1 - arch/arc/mm/init.c | 2 -- arch/arm/mm/mmu.c | 2 -- arch/arm/mm/nommu.c | 1 - arch/arm64/mm/init.c | 2 -- arch/csky/mm/init.c | 1 - arch/hexagon/mm/init.c | 6 ------ arch/loongarch/kernel/numa.c | 1 - arch/loongarch/mm/init.c | 2 -- arch/m68k/mm/init.c | 2 -- arch/m68k/mm/mcfmmu.c | 1 - arch/m68k/mm/motorola.c | 2 -- arch/m68k/sun3/config.c | 1 - arch/microblaze/mm/init.c | 2 -- arch/mips/mm/init.c | 2 -- arch/nios2/mm/init.c | 6 ------ arch/openrisc/mm/init.c | 2 -- arch/parisc/mm/init.c | 1 - arch/powerpc/kernel/setup-common.c | 1 - arch/riscv/mm/init.c | 1 - arch/s390/mm/init.c | 2 -- arch/sh/mm/init.c | 7 ------- arch/sparc/mm/init_32.c | 1 - arch/sparc/mm/init_64.c | 2 -- arch/um/kernel/um_arch.c | 1 - arch/x86/kernel/setup.c | 2 -- arch/x86/mm/init_32.c | 3 --- arch/x86/mm/numa_32.c | 3 --- arch/xtensa/mm/init.c | 2 -- mm/memory.c | 8 -------- mm/mm_init.c | 23 +++++++++++++++++++++++ mm/nommu.c | 2 -- 32 files changed, 23 insertions(+), 72 deletions(-)
diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index ec0eeae9c653..3ab2d2f3c917 100644
--- 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) { - 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 7ef883d58dc1..05025122e965 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c@@ -150,8 +150,6 @@ void __init setup_arch_memory(void) */ max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; - high_memory = (void *)(min_high_pfn << PAGE_SHIFT); - arch_pfn_offset = min(min_low_pfn, min_high_pfn); kmap_init(); #endif /* CONFIG_HIGHMEM */
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index f02f872ea8a9..e492d58a0386 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c@@ -1250,8 +1250,6 @@ void __init adjust_lowmem_bounds(void) arm_lowmem_limit = lowmem_limit; - high_memory = __va(arm_lowmem_limit - 1) + 1; - if (!memblock_limit) memblock_limit = arm_lowmem_limit;
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index 1a8f6914ee59..65903ed5e80d 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c@@ -146,7 +146,6 @@ void __init adjust_lowmem_bounds(void) phys_addr_t end; adjust_lowmem_bounds_mpu(); end = memblock_end_of_DRAM(); - high_memory = __va(end - 1) + 1; memblock_set_current_limit(end); }
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 9c0b8d9558fc..a48fcccd67fa 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c@@ -314,8 +314,6 @@ void __init arm64_memblock_init(void) } early_init_fdt_scan_reserved_mem(); - - high_memory = __va(memblock_end_of_DRAM() - 1) + 1; } void __init bootmem_init(void)
diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
index ba6694d6170a..a22801aa503a 100644
--- a/arch/csky/mm/init.c
+++ b/arch/csky/mm/init.c@@ -47,7 +47,6 @@ void __init mem_init(void) #ifdef CONFIG_HIGHMEM unsigned long tmp; #endif - high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); memblock_free_all();
diff --git a/arch/hexagon/mm/init.c b/arch/hexagon/mm/init.c
index 508bb6a8dcc9..d412c2314509 100644
--- a/arch/hexagon/mm/init.c
+++ b/arch/hexagon/mm/init.c@@ -100,12 +100,6 @@ static void __init paging_init(void) * initial kernel segment table's physical address. */ init_mm.context.ptbase = __pa(init_mm.pgd); - - /* - * Start of high memory area. Will probably need something more - * fancy if we... get more fancy. - */ - high_memory = (void *)((bootmem_lastpg + 1) << PAGE_SHIFT); } #ifndef DMA_RESERVE
diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
index 84fe7f854820..8eb489725b1a 100644
--- a/arch/loongarch/kernel/numa.c
+++ b/arch/loongarch/kernel/numa.c@@ -389,7 +389,6 @@ void __init paging_init(void) void __init mem_init(void) { - high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); memblock_free_all(); }
diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
index 00449df50db1..6affa3609188 100644
--- a/arch/loongarch/mm/init.c
+++ b/arch/loongarch/mm/init.c@@ -78,8 +78,6 @@ void __init paging_init(void) void __init mem_init(void) { - high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); - memblock_free_all(); } #endif /* !CONFIG_NUMA */
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index 8b11d0d545aa..e03ac556c59e 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c@@ -66,8 +66,6 @@ void __init paging_init(void) unsigned long end_mem = memory_end & PAGE_MASK; unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, }; - high_memory = (void *) end_mem; - empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE); max_zone_pfn[ZONE_DMA] = end_mem >> PAGE_SHIFT; free_area_init(max_zone_pfn);
diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
index 19a75029036c..1750cf9f0369 100644
--- a/arch/m68k/mm/mcfmmu.c
+++ b/arch/m68k/mm/mcfmmu.c@@ -168,7 +168,6 @@ void __init cf_bootmem_alloc(void) memstart = PAGE_ALIGN(_ramstart); min_low_pfn = PFN_DOWN(_rambase); max_pfn = max_low_pfn = PFN_DOWN(_ramend); - high_memory = (void *)_ramend; /* Reserve kernel text/data/bss */ memblock_reserve(_rambase, memstart - _rambase);
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 73651e093c4d..312efcd4b353 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c@@ -472,8 +472,6 @@ void __init paging_init(void) module_fixup(NULL, __start_fixup, __stop_fixup); flush_icache(); - high_memory = phys_to_virt(max_addr) + 1; - min_low_pfn = availmem >> PAGE_SHIFT; max_pfn = max_low_pfn = (max_addr >> PAGE_SHIFT) + 1;
diff --git a/arch/m68k/sun3/config.c b/arch/m68k/sun3/config.c
index cd8af809e0ca..925818278e34 100644
--- a/arch/m68k/sun3/config.c
+++ b/arch/m68k/sun3/config.c@@ -115,7 +115,6 @@ static void __init sun3_bootmem_alloc(unsigned long memory_start, max_pfn = num_pages = __pa(memory_end) >> PAGE_SHIFT; - high_memory = (void *)memory_end; availmem = memory_start; m68k_setup_node(0);
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 857cd2b44bcf..7e2e342e84c5 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c@@ -120,8 +120,6 @@ void __init setup_memory(void) void __init mem_init(void) { - high_memory = (void *)__va(memory_start + lowmem_size - 1); - /* this will put all memory onto the freelists */ memblock_free_all(); #ifdef CONFIG_HIGHMEM
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 338b3c9fc5bc..99cefb58fba3 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c@@ -419,7 +419,6 @@ void __init paging_init(void) max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn; } #endif - high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); free_area_init(max_zone_pfns); }
@@ -471,7 +470,6 @@ void __init mem_init(void) #else /* CONFIG_NUMA */ void __init mem_init(void) { - high_memory = (void *) __va(get_num_physpages() << PAGE_SHIFT); setup_zero_pages(); /* This comes from node 0 */ memblock_free_all(); }
diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
index 3cafa87ead9e..4ba8dfa0d238 100644
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c@@ -62,12 +62,6 @@ void __init paging_init(void) void __init mem_init(void) { - unsigned long end_mem = memory_end; /* this must not include - kernel stack at top */ - - end_mem &= PAGE_MASK; - high_memory = __va(end_mem); - /* this will put all memory onto the freelists */ memblock_free_all(); }
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index 9093c336e158..72c5952607ac 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c@@ -193,8 +193,6 @@ void __init mem_init(void) { BUG_ON(!mem_map); - high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); - /* clear the zero-page */ memset((void *)empty_zero_page, 0, PAGE_SIZE);
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 2cdfc0b1195c..4fbe354dc9b4 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c@@ -562,7 +562,6 @@ void __init mem_init(void) BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000); #endif - high_memory = __va((max_pfn << PAGE_SHIFT)); memblock_free_all(); #ifdef CONFIG_PA11
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 68d47c53876c..de34c40ccb21 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c@@ -957,7 +957,6 @@ void __init setup_arch(char **cmdline_p) /* Parse memory topology */ mem_topology_setup(); - high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); /* * Release secondary cpus out of their spinloops at 0x60 now that
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 157c9ca51541..ac6d41e86243 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c@@ -295,7 +295,6 @@ static void __init setup_bootmem(void) phys_ram_end = memblock_end_of_DRAM(); min_low_pfn = PFN_UP(phys_ram_base); max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end); - high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 7e64243693c9..08ebc9a9344a 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c@@ -161,8 +161,6 @@ void __init mem_init(void) cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); cpumask_set_cpu(0, mm_cpumask(&init_mm)); - high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); - pv_init(); kfence_split_mapping();
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 72aea5cd1b85..6d459ffba4bc 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c@@ -330,13 +330,6 @@ unsigned int mem_init_done = 0; void __init mem_init(void) { - pg_data_t *pgdat; - - high_memory = NULL; - for_each_online_pgdat(pgdat) - high_memory = max_t(void *, high_memory, - __va(pgdat_end_pfn(pgdat) << PAGE_SHIFT)); - memblock_free_all(); /* Set this up early, so we can take care of the zero page */
diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index 6b58da14edc6..81a468a9c223 100644
--- 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(); - high_memory = __va(max_low_pfn << PAGE_SHIFT); memblock_free_all(); for (i = 0; sp_banks[i].num_bytes != 0; i++) {
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 05882bca5b73..34d46adb9571 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c@@ -2505,8 +2505,6 @@ static void __init register_page_bootmem_info(void) } void __init mem_init(void) { - high_memory = __va(last_valid_pfn << PAGE_SHIFT); - memblock_free_all(); /*
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 6414cbf00572..f24a3ce37ab7 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c@@ -385,7 +385,6 @@ int __init linux_main(int argc, char **argv, char **envp) high_physmem = uml_physmem + physmem_size; end_iomem = high_physmem + iomem_size; - high_memory = (void *) end_iomem; start_vm = VMALLOC_START;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index cebee310e200..5c9ec876915e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c@@ -972,8 +972,6 @@ void __init setup_arch(char **cmdline_p) max_low_pfn = e820__end_of_low_ram_pfn(); else max_low_pfn = max_pfn; - - high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; #endif /* Find and reserve MPTABLE area */
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 6d2f8cb9451e..801b659ead0c 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c@@ -643,9 +643,6 @@ void __init initmem_init(void) highstart_pfn = max_low_pfn; printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", pages_to_mb(highend_pfn - highstart_pfn)); - high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; -#else - high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; #endif memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
diff --git a/arch/x86/mm/numa_32.c b/arch/x86/mm/numa_32.c
index 65fda406e6f2..442ef3facff0 100644
--- a/arch/x86/mm/numa_32.c
+++ b/arch/x86/mm/numa_32.c@@ -41,9 +41,6 @@ void __init initmem_init(void) highstart_pfn = max_low_pfn; printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", pages_to_mb(highend_pfn - highstart_pfn)); - high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; -#else - high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; #endif printk(KERN_NOTICE "%ldMB LOWMEM available.\n", pages_to_mb(max_low_pfn));
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 9f1b0d5fccc7..9b662477b3d4 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c@@ -164,8 +164,6 @@ void __init mem_init(void) { free_highpages(); - high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT); - memblock_free_all(); }
diff --git a/mm/memory.c b/mm/memory.c
index 126fdd3001e3..2351f3f6b9ed 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -113,14 +113,6 @@ static __always_inline bool vmf_orig_pte_uffd_wp(struct vm_fault *vmf) return pte_marker_uffd_wp(vmf->orig_pte); } -/* - * A number of key systems in x86 including ioremap() rely on the assumption - * that high_memory defines the upper bound on direct map memory, then end - * of ZONE_NORMAL. - */ -void *high_memory; -EXPORT_SYMBOL(high_memory); - /* * Randomize the address space (stacks, mmaps, brk, etc.). *
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 50a93714e1c6..5e5f6ba73757 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c@@ -44,6 +44,13 @@ struct page *mem_map; EXPORT_SYMBOL(mem_map); #endif +/* + * high_memory defines the upper bound on direct map memory, then end + * of ZONE_NORMAL. + */ +void *high_memory; +EXPORT_SYMBOL(high_memory); + #ifdef CONFIG_DEBUG_MEMORY_INIT int __meminitdata mminit_loglevel;
@@ -1756,6 +1763,20 @@ static bool arch_has_descending_max_zone_pfns(void) return IS_ENABLED(CONFIG_ARC) && !IS_ENABLED(CONFIG_ARC_HAS_PAE40); } +static void set_high_memory(void) +{ + phys_addr_t highmem = memblock_end_of_DRAM(); + +#ifdef CONFIG_HIGHMEM + unsigned long pfn = arch_zone_lowest_possible_pfn[ZONE_HIGHMEM]; + + if (arch_has_descending_max_zone_pfns() || highmem > PFN_PHYS(pfn)) + highmem = PFN_PHYS(pfn); +#endif + + high_memory = phys_to_virt(highmem - 1) + 1; +} + /** * free_area_init - Initialise all pg_data_t and zone data * @max_zone_pfn: an array of max PFNs for each zone
@@ -1875,6 +1896,8 @@ void __init free_area_init(unsigned long *max_zone_pfn) /* disable hash distribution for systems with a single node */ fixup_hashdist(); + + set_high_memory(); } /**
diff --git a/mm/nommu.c b/mm/nommu.c
index f0209dd26dfa..b9783638fbd4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c@@ -42,8 +42,6 @@ #include <asm/mmu_context.h> #include "internal.h" -void *high_memory; -EXPORT_SYMBOL(high_memory); unsigned long highest_memmap_pfn; int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; int heap_stack_gap = 0;
--
2.47.2