@@ -28,6 +28,9 @@
#define KEXEC_ARCH KEXEC_ARCH_AARCH64
+/* 2M alignment for crash kernel regions */
+#define CRASH_ALIGN SZ_2M
+
#ifndef __ASSEMBLY__
/**
@@ -243,6 +243,9 @@ static void __init request_standard_resources(void)
request_resource(res, &kernel_data);
#ifdef CONFIG_KEXEC_CORE
/* Userspace will find "Crash kernel" region in /proc/iomem. */
+ if (crashk_low_res.end && crashk_low_res.start >= res->start &&
+ crashk_low_res.end <= res->end)
+ request_resource(res, &crashk_low_res);
if (crashk_res.end && crashk_res.start >= res->start &&
crashk_res.end <= res->end)
request_resource(res, &crashk_res);
@@ -64,6 +64,7 @@ EXPORT_SYMBOL(memstart_addr);
phys_addr_t arm64_dma_phys_limit __ro_after_init;
#ifdef CONFIG_KEXEC_CORE
+
/*
* reserve_crashkernel() - reserves memory for crash kernel
*
@@ -74,20 +75,30 @@ phys_addr_t arm64_dma_phys_limit __ro_after_init;
static void __init reserve_crashkernel(void)
{
unsigned long long crash_base, crash_size;
+ bool high = false;
int ret;
ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
&crash_size, &crash_base);
/* no crashkernel= or invalid value specified */
- if (ret || !crash_size)
- return;
+ if (ret || !crash_size) {
+ /* crashkernel=X,high */
+ ret = parse_crashkernel_high(boot_command_line,
+ memblock_phys_mem_size(),
+ &crash_size, &crash_base);
+ if (ret || !crash_size)
+ return;
+ high = true;
+ }
crash_size = PAGE_ALIGN(crash_size);
if (crash_base == 0) {
/* Current arm64 boot protocol requires 2MB alignment */
- crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,
- crash_size, SZ_2M);
+ crash_base = memblock_find_in_range(0,
+ high ? memblock_end_of_DRAM()
+ : ARCH_LOW_ADDRESS_LIMIT,
+ crash_size, CRASH_ALIGN);
if (crash_base == 0) {
pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
crash_size);
@@ -105,13 +116,18 @@ static void __init reserve_crashkernel(void)
return;
}
- if (!IS_ALIGNED(crash_base, SZ_2M)) {
+ if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) {
pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n");
return;
}
}
memblock_reserve(crash_base, crash_size);
+ if (crash_base >= SZ_4G && reserve_crashkernel_low()) {
+ memblock_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);
@@ -18,6 +18,9 @@
# define KEXEC_CONTROL_CODE_MAX_SIZE 2048
+/* 16M alignment for crash kernel regions */
+#define CRASH_ALIGN (16 << 20)
+
#ifndef __ASSEMBLY__
#include <linux/string.h>
@@ -447,9 +447,6 @@ static void __init memblock_x86_reserve_range_setup_data(void)
#ifdef CONFIG_KEXEC_CORE
-/* 16M alignment for crash kernel regions */
-#define CRASH_ALIGN (16 << 20)
-
/*
* 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.
@@ -463,59 +460,6 @@ static void __init memblock_x86_reserve_range_setup_data(void)
# define CRASH_ADDR_HIGH_MAX MAXMEM
#endif
-static int __init reserve_crashkernel_low(void)
-{
-#ifdef CONFIG_X86_64
- unsigned long long base, low_base = 0, low_size = 0;
- unsigned long total_low_mem;
- int ret;
-
- total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
-
- /* crashkernel=Y,low */
- ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
- if (ret) {
- /*
- * two parts from lib/swiotlb.c:
- * -swiotlb size: user-specified with swiotlb= or default.
- *
- * -swiotlb overflow buffer: now hardcoded to 32k. We round it
- * to 8M for other buffers that may need to stay low too. Also
- * make sure we allocate enough extra low memory so that we
- * don't run out of DMA buffers for 32-bit devices.
- */
- low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
- } else {
- /* passed with crashkernel=0,low ? */
- if (!low_size)
- return 0;
- }
-
- low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
- if (!low_base) {
- pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
- (unsigned long)(low_size >> 20));
- return -ENOMEM;
- }
-
- ret = memblock_reserve(low_base, low_size);
- if (ret) {
- pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
- return ret;
- }
-
- pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
- (unsigned long)(low_size >> 20),
- (unsigned long)(low_base >> 20),
- (unsigned long)(total_low_mem >> 20));
-
- crashk_low_res.start = low_base;
- crashk_low_res.end = low_base + low_size - 1;
- insert_resource(&iomem_resource, &crashk_low_res);
-#endif
- return 0;
-}
-
static void __init reserve_crashkernel(void)
{
unsigned long long crash_size, crash_base, total_mem;
@@ -573,9 +517,13 @@ static void __init reserve_crashkernel(void)
return;
}
- if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
- memblock_free(crash_base, crash_size);
- return;
+ if (crash_base >= (1ULL << 32)) {
+ if (reserve_crashkernel_low()) {
+ memblock_free(crash_base, crash_size);
+ return;
+ }
+
+ insert_resource(&iomem_resource, &crashk_low_res);
}
pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
@@ -281,6 +281,7 @@ extern void __crash_kexec(struct pt_regs *);
extern void crash_kexec(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
int kexec_crash_loaded(void);
+int __init reserve_crashkernel_low(void);
void crash_save_cpu(struct pt_regs *regs, int cpu);
extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
@@ -39,6 +39,8 @@
#include <linux/compiler.h>
#include <linux/hugetlb.h>
#include <linux/frame.h>
+#include <linux/memblock.h>
+#include <linux/swiotlb.h>
#include <asm/page.h>
#include <asm/sections.h>
@@ -96,6 +98,57 @@ int kexec_crash_loaded(void)
}
EXPORT_SYMBOL_GPL(kexec_crash_loaded);
+int __init reserve_crashkernel_low(void)
+{
+ unsigned long long base, low_base = 0, low_size = 0;
+ unsigned long total_low_mem;
+ int ret;
+
+ total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
+
+ /* crashkernel=Y,low */
+ ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
+ if (ret) {
+ /*
+ * two parts from lib/swiotlb.c:
+ * -swiotlb size: user-specified with swiotlb= or default.
+ *
+ * -swiotlb overflow buffer: now hardcoded to 32k. We round it
+ * to 8M for other buffers that may need to stay low too. Also
+ * make sure we allocate enough extra low memory so that we
+ * don't run out of DMA buffers for 32-bit devices.
+ */
+ low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
+ } else {
+ /* passed with crashkernel=0,low ? */
+ if (!low_size)
+ return 0;
+ }
+
+ low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
+ if (!low_base) {
+ pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
+ (unsigned long)(low_size >> 20));
+ return -ENOMEM;
+ }
+
+ ret = memblock_reserve(low_base, low_size);
+ if (ret) {
+ pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
+ return ret;
+ }
+
+ pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
+ (unsigned long)(low_size >> 20),
+ (unsigned long)(low_base >> 20),
+ (unsigned long)(total_low_mem >> 20));
+
+ crashk_low_res.start = low_base;
+ crashk_low_res.end = low_base + low_size - 1;
+
+ return 0;
+}
+
/*
* When kexec transitions to the new kernel there is a one-to-one
* mapping between physical and virtual addresses. On processors
When crashkernel is reserved above 4G in memory, kernel should reserve some amount of low memory for swiotlb and some DMA buffers. Kernel would try to allocate at least 256M below 4G automatically as x86_64 if crashkernel is above 4G. Meanwhile, support crashkernel=X,[high,low] in arm64. Signed-off-by: Chen Zhou <chenzhou10@huawei.com> --- arch/arm64/include/asm/kexec.h | 3 ++ arch/arm64/kernel/setup.c | 3 ++ arch/arm64/mm/init.c | 26 +++++++++++++---- arch/x86/include/asm/kexec.h | 3 ++ arch/x86/kernel/setup.c | 66 +++++------------------------------------- include/linux/kexec.h | 1 + kernel/kexec_core.c | 53 +++++++++++++++++++++++++++++++++ 7 files changed, 91 insertions(+), 64 deletions(-)