From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/xtensa/mm/init.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 arch/xtensa/mm/init.c (limited to 'arch/xtensa/mm/init.c') diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c new file mode 100644 index 000000000..fe83a6833 --- /dev/null +++ b/arch/xtensa/mm/init.c @@ -0,0 +1,202 @@ +/* + * arch/xtensa/mm/init.c + * + * Derived from MIPS, PPC. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2014 - 2016 Cadence Design Systems Inc. + * + * Chris Zankel + * Joe Taylor + * Marc Gauthier + * Kevin Chea + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +/* + * Initialize the bootmem system and give it all low memory we have available. + */ + +void __init bootmem_init(void) +{ + /* Reserve all memory below PHYS_OFFSET, as memory + * accounting doesn't work for pages below that address. + * + * If PHYS_OFFSET is zero reserve page at address 0: + * successfull allocations should never return NULL. + */ + memblock_reserve(0, PHYS_OFFSET ? PHYS_OFFSET : 1); + + early_init_fdt_scan_reserved_mem(); + + if (!memblock_phys_mem_size()) + panic("No memory found!\n"); + + min_low_pfn = PFN_UP(memblock_start_of_DRAM()); + min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET)); + max_pfn = PFN_DOWN(memblock_end_of_DRAM()); + max_low_pfn = min(max_pfn, MAX_LOW_PFN); + + early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT, + (phys_addr_t)max_low_pfn << PAGE_SHIFT); + + memblock_set_current_limit(PFN_PHYS(max_low_pfn)); + dma_contiguous_reserve(PFN_PHYS(max_low_pfn)); + + memblock_dump_all(); +} + +static void __init print_vm_layout(void) +{ + pr_info("virtual kernel memory layout:\n" +#ifdef CONFIG_KASAN + " kasan : 0x%08lx - 0x%08lx (%5lu MB)\n" +#endif +#ifdef CONFIG_MMU + " vmalloc : 0x%08lx - 0x%08lx (%5lu MB)\n" +#endif +#ifdef CONFIG_HIGHMEM + " pkmap : 0x%08lx - 0x%08lx (%5lu kB)\n" + " fixmap : 0x%08lx - 0x%08lx (%5lu kB)\n" +#endif + " lowmem : 0x%08lx - 0x%08lx (%5lu MB)\n" + " .text : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .rodata : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .data : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .init : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .bss : 0x%08lx - 0x%08lx (%5lu kB)\n", +#ifdef CONFIG_KASAN + KASAN_SHADOW_START, KASAN_SHADOW_START + KASAN_SHADOW_SIZE, + KASAN_SHADOW_SIZE >> 20, +#endif +#ifdef CONFIG_MMU + VMALLOC_START, VMALLOC_END, + (VMALLOC_END - VMALLOC_START) >> 20, +#ifdef CONFIG_HIGHMEM + PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE, + (LAST_PKMAP*PAGE_SIZE) >> 10, + FIXADDR_START, FIXADDR_END, + (FIXADDR_END - FIXADDR_START) >> 10, +#endif + PAGE_OFFSET, PAGE_OFFSET + + (max_low_pfn - min_low_pfn) * PAGE_SIZE, +#else + min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE, +#endif + ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20, + (unsigned long)_text, (unsigned long)_etext, + (unsigned long)(_etext - _text) >> 10, + (unsigned long)__start_rodata, (unsigned long)__end_rodata, + (unsigned long)(__end_rodata - __start_rodata) >> 10, + (unsigned long)_sdata, (unsigned long)_edata, + (unsigned long)(_edata - _sdata) >> 10, + (unsigned long)__init_begin, (unsigned long)__init_end, + (unsigned long)(__init_end - __init_begin) >> 10, + (unsigned long)__bss_start, (unsigned long)__bss_stop, + (unsigned long)(__bss_stop - __bss_start) >> 10); +} + +void __init arch_zone_limits_init(unsigned long *max_zone_pfns) +{ + max_zone_pfns[ZONE_NORMAL] = max_low_pfn; +#ifdef CONFIG_HIGHMEM + max_zone_pfns[ZONE_HIGHMEM] = max_pfn; +#endif +} + +void __init zones_init(void) +{ + print_vm_layout(); +} + +static void __init parse_memmap_one(char *p) +{ + char *oldp; + unsigned long start_at, mem_size; + + if (!p) + return; + + oldp = p; + mem_size = memparse(p, &p); + if (p == oldp) + return; + + switch (*p) { + case '@': + start_at = memparse(p + 1, &p); + memblock_add(start_at, mem_size); + break; + + case '$': + start_at = memparse(p + 1, &p); + memblock_reserve(start_at, mem_size); + break; + + case 0: + memblock_reserve(mem_size, -mem_size); + break; + + default: + pr_warn("Unrecognized memmap syntax: %s\n", p); + break; + } +} + +static int __init parse_memmap_opt(char *str) +{ + while (str) { + char *k = strchr(str, ','); + + if (k) + *k++ = 0; + + parse_memmap_one(str); + str = k; + } + + return 0; +} +early_param("memmap", parse_memmap_opt); + +#ifdef CONFIG_MMU +static const pgprot_t protection_map[16] = { + [VM_NONE] = PAGE_NONE, + [VM_READ] = PAGE_READONLY, + [VM_WRITE] = PAGE_COPY, + [VM_WRITE | VM_READ] = PAGE_COPY, + [VM_EXEC] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC, + [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC, + [VM_SHARED] = PAGE_NONE, + [VM_SHARED | VM_READ] = PAGE_READONLY, + [VM_SHARED | VM_WRITE] = PAGE_SHARED, + [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, + [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC +}; +DECLARE_VM_GET_PAGE_PROT +#endif -- cgit v1.3.1