From patchwork Thu Mar 6 18:51:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 14005185 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BB1CE26FDA6; Thu, 6 Mar 2025 18:53:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741287236; cv=none; b=SjEjl4CZrLAOYQvs/lpm1vWrWti22F09E/jid1Pyir0NrQApHWsL/5A2hj+rSowPOU+KcV6EeQgqhYAemW6qw/szyuH7AxxiX6Q5lpzac7XyVIIaxIQyXdjURfjB6Tbzx2U1yLO+HfTR6oPk42ABZJHaaZqdgY0v7iHF6oB3u8A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741287236; c=relaxed/simple; bh=N82KtXPTFRyks1M44cPPRNwY3qzMhZjfhHPDkzfY8rc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hQsiy5mLa1QIPy4EeiHBmSFRsO7b/jowLQ28pGLsmoPYOOPKpHEbDSTSnBXCrY6bWJjJFGqaYks4quqkLHjJ03PVmXi9p6JMp0/tDEi+XNdifeLMgI04QRrf7slFqtfmyXl7H0OVD0VOhlSF1YWtGZIFoV5O2sQelFDPkU+ZSug= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KHBmfR60; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KHBmfR60" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC2AFC4CEE0; Thu, 6 Mar 2025 18:53:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741287236; bh=N82KtXPTFRyks1M44cPPRNwY3qzMhZjfhHPDkzfY8rc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KHBmfR60iylGj76PcT5SR7iJdsxbhA2Op+45b52Rs6V3kvzzkbh7AD6HEff+L65Hh xV0sL9zAxkHRgn2L9BsKzOGu3B/4Z0X1T/iAyacvyctkIjJOG4pG91QEtBsGACBUg8 nU35JgjU4cUQEzRF+SZgMrTeY64fMzNGDm2r6hZWXBdNPRBOi5QSkoA2qThxQvajNu fmWs3Nb6Wt2+0q0UN7j2wVSLURdOagBUsixRBdAqyIFyK5FmhDQI0oLDouhgQERSL1 vd5xfzqJGRd07zHsmoNtbnlpkmmbxEcGXST9cCCGirN8KhrhPFUgVkjm8Wfik22qcU T4FkPG9Lanq/g== From: Mike Rapoport To: Andrew Morton Cc: Alexander Gordeev , Andreas Larsson , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Brian Cain , Catalin Marinas , Dave Hansen , "David S. Miller" , Dinh Nguyen , Geert Uytterhoeven , Gerald Schaefer , Guo Ren , Heiko Carstens , Helge Deller , Huacai Chen , Ingo Molnar , Jiaxun Yang , Johannes Berg , John Paul Adrian Glaubitz , Madhavan Srinivasan , Matt Turner , Max Filippov , Michael Ellerman , Michal Simek , Mike Rapoport , Palmer Dabbelt , Peter Zijlstra , Richard Weinberger , Russell King , Stafford Horne , Thomas Bogendoerfer , Thomas Gleixner , Vasily Gorbik , Vineet Gupta , Will Deacon , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: [PATCH 10/13] arch, mm: set high_memory in free_area_init() Date: Thu, 6 Mar 2025 20:51:20 +0200 Message-ID: <20250306185124.3147510-11-rppt@kernel.org> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250306185124.3147510-1-rppt@kernel.org> References: <20250306185124.3147510-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Mike Rapoport (Microsoft)" 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) --- 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 #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;