forked from Minki/linux
72d7c3b33c
1. replace find_e820_area with memblock_find_in_range 2. replace reserve_early with memblock_x86_reserve_range 3. replace free_early with memblock_x86_free_range. 4. NO_BOOTMEM will switch to use memblock too. 5. use _e820, _early wrap in the patch, in following patch, will replace them all 6. because memblock_x86_free_range support partial free, we can remove some special care 7. Need to make sure that memblock_find_in_range() is called after memblock_x86_fill() so adjust some calling later in setup.c::setup_arch() -- corruption_check and mptable_update -v2: Move reserve_brk() early Before fill_memblock_area, to avoid overlap between brk and memblock_find_in_range() that could happen We have more then 128 RAM entry in E820 tables, and memblock_x86_fill() could use memblock_find_in_range() to find a new place for memblock.memory.region array. and We don't need to use extend_brk() after fill_memblock_area() So move reserve_brk() early before fill_memblock_area(). -v3: Move find_smp_config early To make sure memblock_find_in_range not find wrong place, if BIOS doesn't put mptable in right place. -v4: Treat RESERVED_KERN as RAM in memblock.memory. and they are already in memblock.reserved already.. use __NOT_KEEP_MEMBLOCK to make sure memblock related code could be freed later. -v5: Generic version __memblock_find_in_range() is going from high to low, and for 32bit active_region for 32bit does include high pages need to replace the limit with memblock.default_alloc_limit, aka get_max_mapped() -v6: Use current_limit instead -v7: check with MEMBLOCK_ERROR instead of -1ULL or -1L -v8: Set memblock_can_resize early to handle EFI with more RAM entries -v9: update after kmemleak changes in mainline Suggested-by: David S. Miller <davem@davemloft.net> Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
164 lines
3.8 KiB
C
164 lines
3.8 KiB
C
#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/kthread.h>
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#include <linux/workqueue.h>
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#include <linux/memblock.h>
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#include <asm/proto.h>
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/*
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* Some BIOSes seem to corrupt the low 64k of memory during events
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* like suspend/resume and unplugging an HDMI cable. Reserve all
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* remaining free memory in that area and fill it with a distinct
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* pattern.
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*/
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#define MAX_SCAN_AREAS 8
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static int __read_mostly memory_corruption_check = -1;
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static unsigned __read_mostly corruption_check_size = 64*1024;
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static unsigned __read_mostly corruption_check_period = 60; /* seconds */
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static struct scan_area {
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u64 addr;
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u64 size;
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} scan_areas[MAX_SCAN_AREAS];
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static int num_scan_areas;
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static __init int set_corruption_check(char *arg)
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{
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char *end;
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memory_corruption_check = simple_strtol(arg, &end, 10);
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return (*end == 0) ? 0 : -EINVAL;
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}
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early_param("memory_corruption_check", set_corruption_check);
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static __init int set_corruption_check_period(char *arg)
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{
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char *end;
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corruption_check_period = simple_strtoul(arg, &end, 10);
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return (*end == 0) ? 0 : -EINVAL;
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}
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early_param("memory_corruption_check_period", set_corruption_check_period);
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static __init int set_corruption_check_size(char *arg)
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{
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char *end;
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unsigned size;
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size = memparse(arg, &end);
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if (*end == '\0')
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corruption_check_size = size;
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return (size == corruption_check_size) ? 0 : -EINVAL;
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}
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early_param("memory_corruption_check_size", set_corruption_check_size);
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void __init setup_bios_corruption_check(void)
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{
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u64 addr = PAGE_SIZE; /* assume first page is reserved anyway */
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if (memory_corruption_check == -1) {
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memory_corruption_check =
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#ifdef CONFIG_X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
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1
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#else
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0
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#endif
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;
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}
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if (corruption_check_size == 0)
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memory_corruption_check = 0;
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if (!memory_corruption_check)
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return;
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corruption_check_size = round_up(corruption_check_size, PAGE_SIZE);
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while (addr < corruption_check_size && num_scan_areas < MAX_SCAN_AREAS) {
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u64 size;
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addr = memblock_x86_find_in_range_size(addr, &size, PAGE_SIZE);
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if (addr == MEMBLOCK_ERROR)
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break;
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if (addr >= corruption_check_size)
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break;
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if ((addr + size) > corruption_check_size)
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size = corruption_check_size - addr;
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memblock_x86_reserve_range(addr, addr + size, "SCAN RAM");
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scan_areas[num_scan_areas].addr = addr;
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scan_areas[num_scan_areas].size = size;
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num_scan_areas++;
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/* Assume we've already mapped this early memory */
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memset(__va(addr), 0, size);
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addr += size;
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}
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printk(KERN_INFO "Scanning %d areas for low memory corruption\n",
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num_scan_areas);
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}
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void check_for_bios_corruption(void)
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{
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int i;
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int corruption = 0;
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if (!memory_corruption_check)
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return;
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for (i = 0; i < num_scan_areas; i++) {
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unsigned long *addr = __va(scan_areas[i].addr);
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unsigned long size = scan_areas[i].size;
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for (; size; addr++, size -= sizeof(unsigned long)) {
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if (!*addr)
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continue;
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printk(KERN_ERR "Corrupted low memory at %p (%lx phys) = %08lx\n",
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addr, __pa(addr), *addr);
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corruption = 1;
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*addr = 0;
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}
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}
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WARN_ONCE(corruption, KERN_ERR "Memory corruption detected in low memory\n");
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}
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static void check_corruption(struct work_struct *dummy);
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static DECLARE_DELAYED_WORK(bios_check_work, check_corruption);
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static void check_corruption(struct work_struct *dummy)
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{
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check_for_bios_corruption();
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schedule_delayed_work(&bios_check_work,
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round_jiffies_relative(corruption_check_period*HZ));
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}
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static int start_periodic_check_for_corruption(void)
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{
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if (!memory_corruption_check || corruption_check_period == 0)
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return 0;
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printk(KERN_INFO "Scanning for low memory corruption every %d seconds\n",
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corruption_check_period);
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/* First time we run the checks right away */
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schedule_delayed_work(&bios_check_work, 0);
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return 0;
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}
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module_init(start_periodic_check_for_corruption);
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