riscv: 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/riscv/Kconfig.

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

[chenjiahao16@huawei.com: fix crashkernel reserving problem on RISC-V]
Link: https://lkml.kernel.org/r/20230925024333.730964-1-chenjiahao16@huawei.com
Link: https://lkml.kernel.org/r/20230914033142.676708-9-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d607ab0f7c6dafa4f754f34a910ef66464e5a06d..25474f8c12b79b70a00769f622a266da754b3208 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -694,6 +694,9 @@ config ARCH_SUPPORTS_KEXEC_PURGATORY
 config ARCH_SUPPORTS_CRASH_DUMP
        def_bool y
 
+config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+       def_bool CRASH_CORE
+
 config COMPAT
        bool "Kernel support for 32-bit U-mode"
        default 64BIT

diff --git a/arch/riscv/include/asm/crash_core.h b/arch/riscv/include/asm/crash_core.h
new file mode 100644 (file)
index 0000000..e1874b2
--- /dev/null
+++ b/arch/riscv/include/asm/crash_core.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _RISCV_CRASH_CORE_H
+#define _RISCV_CRASH_CORE_H
+
+#define CRASH_ALIGN                    PMD_SIZE
+
+#define CRASH_ADDR_LOW_MAX             dma32_phys_limit
+#define CRASH_ADDR_HIGH_MAX            memblock_end_of_DRAM()
+
+extern phys_addr_t memblock_end_of_DRAM(void);
+#endif

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 3e23e1786d0521678c111c5a94ed33332403b556..441da1839c947803cdcbe177e4292e2b81a9db49 100644 (file)
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -116,6 +116,8 @@ static inline void wait_for_interrupt(void)
        __asm__ __volatile__ ("wfi");
 }
 
+extern phys_addr_t dma32_phys_limit;
+
 struct device_node;
 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index e600aab116a4093a5a45285f3e14e32e917f54ba..aac853ae4eb74e8e228551eb94720611e241c32c 100644 (file)
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -173,19 +173,6 @@ static void __init init_resources(void)
        if (ret < 0)
                goto error;
 
-#ifdef CONFIG_KEXEC_CORE
-       if (crashk_res.start != crashk_res.end) {
-               ret = add_resource(&iomem_resource, &crashk_res);
-               if (ret < 0)
-                       goto error;
-       }
-       if (crashk_low_res.start != crashk_low_res.end) {
-               ret = add_resource(&iomem_resource, &crashk_low_res);
-               if (ret < 0)
-                       goto error;
-       }
-#endif
-
 #ifdef CONFIG_CRASH_DUMP
        if (elfcorehdr_size > 0) {
                elfcorehdr_res.start = elfcorehdr_addr;

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 9fe448900059c1729cbd62a7a0b286c2c93219b7..d9a4e87028644f962f1c51ad3a89c8b475063e05 100644 (file)
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -65,7 +65,7 @@ extern char _start[];
 void *_dtb_early_va __initdata;
 uintptr_t _dtb_early_pa __initdata;
 
-static phys_addr_t dma32_phys_limit __initdata;
+phys_addr_t dma32_phys_limit __initdata;
 
 static void __init zone_sizes_init(void)
 {
@@ -1333,28 +1333,6 @@ static inline void setup_vm_final(void)
 }
 #endif /* CONFIG_MMU */
 
-/* Reserve 128M low memory by default for swiotlb buffer */
-#define DEFAULT_CRASH_KERNEL_LOW_SIZE  (128UL << 20)
-
-static int __init reserve_crashkernel_low(unsigned long long low_size)
-{
-       unsigned long long low_base;
-
-       low_base = memblock_phys_alloc_range(low_size, PMD_SIZE, 0, dma32_phys_limit);
-       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%016llx - 0x%016llx (%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;
-
-       return 0;
-}
-
 /*
  * reserve_crashkernel() - reserves memory for crash kernel
  *
@@ -1362,122 +1340,25 @@ static int __init reserve_crashkernel_low(unsigned long long low_size)
  * 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_base = 0;
-       unsigned long long crash_size = 0;
-       unsigned long long crash_low_size = 0;
-       unsigned long search_start = memblock_start_of_DRAM();
-       unsigned long search_end = (unsigned long)dma32_phys_limit;
+       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 = 0;
+       int ret;
 
        if (!IS_ENABLED(CONFIG_KEXEC_CORE))
                return;
-       /*
-        * Don't reserve a region for a crash kernel on a crash kernel
-        * since it doesn't make much sense and we have limited memory
-        * resources.
-        */
-       if (is_kdump_kernel()) {
-               pr_info("crashkernel: ignoring reservation request\n");
-               return;
-       }
 
        ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
-                               &crash_size, &crash_base, NULL, NULL);
-       if (ret == -ENOENT) {
-               /* Fallback to crashkernel=X,[high,low] */
-               ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base);
-               if (ret || !crash_size)
-                       return;
-
-               /*
-                * crashkernel=Y,low is valid only when crashkernel=X,high
-                * is passed.
-                */
-               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_start = (unsigned long)dma32_phys_limit;
-               search_end = memblock_end_of_DRAM();
-               high = true;
-       } else if (ret || !crash_size) {
-               /* Invalid argument value specified */
+                               &crash_size, &crash_base,
+                               &low_size, &high);
+       if (ret)
                return;
-       }
-
-       crash_size = PAGE_ALIGN(crash_size);
-
-       if (crash_base) {
-               fixed_base = true;
-               search_start = crash_base;
-               search_end = crash_base + crash_size;
-       }
-
-       /*
-        * Current riscv boot protocol requires 2MB alignment for
-        * RV64 and 4MB alignment for RV32 (hugepage size)
-        *
-        * Try to alloc from 32bit addressible physical memory so that
-        * swiotlb can work on the crash kernel.
-        */
-       crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
-                                              search_start, search_end);
-       if (crash_base == 0) {
-               /*
-                * For crashkernel=size[KMG]@offset[KMG], print out failure
-                * message if can't reserve the specified region.
-                */
-               if (fixed_base) {
-                       pr_warn("crashkernel: allocating failed with given size@offset\n");
-                       return;
-               }
-
-               if (high) {
-                       /*
-                        * For crashkernel=size[KMG],high, if the first attempt was
-                        * for high memory, fall back to low memory.
-                        */
-                       search_start = memblock_start_of_DRAM();
-                       search_end = (unsigned long)dma32_phys_limit;
-               } else {
-                       /*
-                        * 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.
-                        */
-                       search_start = (unsigned long)dma32_phys_limit;
-                       search_end = memblock_end_of_DRAM();
-                       crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
-               }
-
-               crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
-                                                      search_start, search_end);
-               if (crash_base == 0) {
-                       pr_warn("crashkernel: couldn't allocate %lldKB\n",
-                               crash_size >> 10);
-                       return;
-               }
-       }
-
-       if ((crash_base >= dma32_phys_limit) && 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);
 
-       crashk_res.start = crash_base;
-       crashk_res.end = crash_base + crash_size - 1;
+       reserve_crashkernel_generic(cmdline, crash_size, crash_base,
+                                   low_size, high);
 }
 
 void __init paging_init(void)
@@ -1495,7 +1376,7 @@ void __init misc_mem_init(void)
        arch_numa_init();
        sparse_init();
        zone_sizes_init();
-       reserve_crashkernel();
+       arch_reserve_crashkernel();
        memblock_dump_all();
 }