x86, kdump: Retore crashkernel= to allocate under 896M

[~andy/linux] / arch / x86 / kernel / setup.c

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 12349202cae71be073b113e49a1fc4a157642455..a85a144f2052bc43bcc1c78c5119f2f1e6dbcf7e 100644 (file)
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -507,11 +507,14 @@ static void __init memblock_x86_reserve_range_setup_data(void)
 /*
  * Keep the crash kernel below this limit.  On 32 bits earlier kernels
  * would limit the kernel to the low 512 MiB due to mapping restrictions.
+ * On 64bit, old kexec-tools need to under 896MiB.
  */
 #ifdef CONFIG_X86_32
-# define CRASH_KERNEL_ADDR_MAX (512 << 20)
+# define CRASH_KERNEL_ADDR_LOW_MAX     (512 << 20)
+# define CRASH_KERNEL_ADDR_HIGH_MAX    (512 << 20)
 #else
-# define CRASH_KERNEL_ADDR_MAX MAXMEM
+# define CRASH_KERNEL_ADDR_LOW_MAX     (896UL<<20)
+# define CRASH_KERNEL_ADDR_HIGH_MAX    MAXMEM
 #endif
 
 static void __init reserve_crashkernel_low(void)
@@ -525,6 +528,7 @@ static void __init reserve_crashkernel_low(void)
        int ret;
 
        total_low_mem = memblock_mem_size(1UL<<(32-PAGE_SHIFT));
+       /* crashkernel_low=YM */
        ret = parse_crashkernel_low(boot_command_line, total_low_mem,
                                                &low_size, &base);
        if (ret != 0) {
@@ -569,14 +573,22 @@ static void __init reserve_crashkernel(void)
        const unsigned long long alignment = 16<<20;    /* 16M */
        unsigned long long total_mem;
        unsigned long long crash_size, crash_base;
+       bool high = false;
        int ret;
 
        total_mem = memblock_phys_mem_size();
 
+       /* crashkernel=XM */
        ret = parse_crashkernel(boot_command_line, total_mem,
                        &crash_size, &crash_base);
-       if (ret != 0 || crash_size <= 0)
-               return;
+       if (ret != 0 || crash_size <= 0) {
+               /* crashkernel_high=XM */
+               ret = parse_crashkernel_high(boot_command_line, total_mem,
+                               &crash_size, &crash_base);
+               if (ret != 0 || crash_size <= 0)
+                       return;
+               high = true;
+       }
 
        /* 0 means: find the address automatically */
        if (crash_base <= 0) {
@@ -584,7 +596,9 @@ static void __init reserve_crashkernel(void)
                 *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
                 */
                crash_base = memblock_find_in_range(alignment,
-                              CRASH_KERNEL_ADDR_MAX, crash_size, alignment);
+                                       high ? CRASH_KERNEL_ADDR_HIGH_MAX :
+                                              CRASH_KERNEL_ADDR_LOW_MAX,
+                                       crash_size, alignment);
 
                if (!crash_base) {
                        pr_info("crashkernel reservation failed - No suitable area found.\n");