arm64: kdump: use generic interface to simplify crashkernel reservation

With the help of newly changed function parse_crashkernel() and generic
reserve_crashkernel_generic(), crashkernel reservation can be simplified
by steps:

1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
   CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
   DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;

2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
   reserve_crashkernel_generic();

3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
   arch/arm64/Kconfig.

The old reserve_crashkernel_low() and reserve_crashkernel() can be
removed.

Link: https://lkml.kernel.org/r/20230914033142.676708-8-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b10515c0200b4044cf37a98cbf83b743664c1b65..e7d374d994adaa5fe40f2965e57d64675b92581f 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1483,6 +1483,9 @@ config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG
 config ARCH_SUPPORTS_CRASH_DUMP
        def_bool y
 
+config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+       def_bool CRASH_CORE
+
 config TRANS_TABLE
        def_bool y
        depends on HIBERNATION || KEXEC_CORE

diff --git a/arch/arm64/include/asm/crash_core.h b/arch/arm64/include/asm/crash_core.h
new file mode 100644 (file)
index 0000000..9f5c8d3
--- /dev/null
+++ b/arch/arm64/include/asm/crash_core.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ARM64_CRASH_CORE_H
+#define _ARM64_CRASH_CORE_H
+
+/* Current arm64 boot protocol requires 2MB alignment */
+#define CRASH_ALIGN                     SZ_2M
+
+#define CRASH_ADDR_LOW_MAX              arm64_dma_phys_limit
+#define CRASH_ADDR_HIGH_MAX             (PHYS_MASK + 1)
+#endif

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 801c59c39a8fc5e2220aaecac4df0053e2d5114b..f2bf32e1937150fec61d1973590e36d97f3e1f19 100644 (file)
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -64,15 +64,6 @@ EXPORT_SYMBOL(memstart_addr);
  */
 phys_addr_t __ro_after_init arm64_dma_phys_limit;
 
-/* Current arm64 boot protocol requires 2MB alignment */
-#define CRASH_ALIGN                    SZ_2M
-
-#define CRASH_ADDR_LOW_MAX             arm64_dma_phys_limit
-#define CRASH_ADDR_HIGH_MAX            (PHYS_MASK + 1)
-#define CRASH_HIGH_SEARCH_BASE         SZ_4G
-
-#define DEFAULT_CRASH_KERNEL_LOW_SIZE  (128UL << 20)
-
 /*
  * To make optimal use of block mappings when laying out the linear
  * mapping, round down the base of physical memory to a size that can
@@ -100,140 +91,25 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit;
 #define ARM64_MEMSTART_ALIGN   (1UL << ARM64_MEMSTART_SHIFT)
 #endif
 
-static int __init reserve_crashkernel_low(unsigned long long low_size)
-{
-       unsigned long long low_base;
-
-       low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
-       if (!low_base) {
-               pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size);
-               return -ENOMEM;
-       }
-
-       pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld MB)\n",
-               low_base, low_base + low_size, low_size >> 20);
-
-       crashk_low_res.start = low_base;
-       crashk_low_res.end   = low_base + low_size - 1;
-       insert_resource(&iomem_resource, &crashk_low_res);
-
-       return 0;
-}
-
-/*
- * reserve_crashkernel() - reserves memory for crash kernel
- *
- * This function reserves memory area given in "crashkernel=" kernel command
- * line parameter. The memory reserved is used by dump capture kernel when
- * primary kernel is crashing.
- */
-static void __init reserve_crashkernel(void)
+static void __init arch_reserve_crashkernel(void)
 {
-       unsigned long long crash_low_size = 0, search_base = 0;
-       unsigned long long crash_max = CRASH_ADDR_LOW_MAX;
+       unsigned long long low_size = 0;
        unsigned long long crash_base, crash_size;
        char *cmdline = boot_command_line;
-       bool fixed_base = false;
        bool high = false;
        int ret;
 
        if (!IS_ENABLED(CONFIG_KEXEC_CORE))
                return;
 
-       /* crashkernel=X[@offset] */
        ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
-                               &crash_size, &crash_base, NULL, NULL);
-       if (ret == -ENOENT) {
-               ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base);
-               if (ret || !crash_size)
-                       return;
-
-               /*
-                * crashkernel=Y,low can be specified or not, but invalid value
-                * is not allowed.
-                */
-               ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base);
-               if (ret == -ENOENT)
-                       crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
-               else if (ret)
-                       return;
-
-               search_base = CRASH_HIGH_SEARCH_BASE;
-               crash_max = CRASH_ADDR_HIGH_MAX;
-               high = true;
-       } else if (ret || !crash_size) {
-               /* The specified value is invalid */
+                               &crash_size, &crash_base,
+                               &low_size, &high);
+       if (ret)
                return;
-       }
-
-       crash_size = PAGE_ALIGN(crash_size);
-
-       /* User specifies base address explicitly. */
-       if (crash_base) {
-               fixed_base = true;
-               search_base = crash_base;
-               crash_max = crash_base + crash_size;
-       }
-
-retry:
-       crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
-                                              search_base, crash_max);
-       if (!crash_base) {
-               /*
-                * For crashkernel=size[KMG]@offset[KMG], print out failure
-                * message if can't reserve the specified region.
-                */
-               if (fixed_base) {
-                       pr_warn("crashkernel reservation failed - memory is in use.\n");
-                       return;
-               }
-
-               /*
-                * For crashkernel=size[KMG], if the first attempt was for
-                * low memory, fall back to high memory, the minimum required
-                * low memory will be reserved later.
-                */
-               if (!high && crash_max == CRASH_ADDR_LOW_MAX) {
-                       crash_max = CRASH_ADDR_HIGH_MAX;
-                       search_base = CRASH_ADDR_LOW_MAX;
-                       crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
-                       goto retry;
-               }
-
-               /*
-                * For crashkernel=size[KMG],high, if the first attempt was
-                * for high memory, fall back to low memory.
-                */
-               if (high && crash_max == CRASH_ADDR_HIGH_MAX) {
-                       crash_max = CRASH_ADDR_LOW_MAX;
-                       search_base = 0;
-                       goto retry;
-               }
-               pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
-                       crash_size);
-               return;
-       }
-
-       if ((crash_base >= CRASH_ADDR_LOW_MAX) && crash_low_size &&
-            reserve_crashkernel_low(crash_low_size)) {
-               memblock_phys_free(crash_base, crash_size);
-               return;
-       }
-
-       pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
-               crash_base, crash_base + crash_size, crash_size >> 20);
-
-       /*
-        * The crashkernel memory will be removed from the kernel linear
-        * map. Inform kmemleak so that it won't try to access it.
-        */
-       kmemleak_ignore_phys(crash_base);
-       if (crashk_low_res.end)
-               kmemleak_ignore_phys(crashk_low_res.start);
 
-       crashk_res.start = crash_base;
-       crashk_res.end = crash_base + crash_size - 1;
-       insert_resource(&iomem_resource, &crashk_res);
+       reserve_crashkernel_generic(cmdline, crash_size, crash_base,
+                                   low_size, high);
 }
 
 /*
@@ -479,7 +355,7 @@ void __init bootmem_init(void)
         * request_standard_resources() depends on crashkernel's memory being
         * reserved, so do it here.
         */
-       reserve_crashkernel();
+       arch_reserve_crashkernel();
 
        memblock_dump_all();
 }