From: Youling Tang <tangyouling@xxxxxxxxxx>
LoongArch already supports two crashkernel regions in kexec-tools, so we
can directly use the common interface to support crashkernel=X,[hign,low]
after commit 0ab97169aa05("crash_core: add generic function to do 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/loongarch/Kconfig.
One can reserve the crash kernel from high memory above DMA zone range
by explicitly passing "crashkernel=X,high"; or reserve a memory range
below 4G with "crashkernel=X,low". Besides, there are few rules need
to take notice:
1) "crashkernel=X,[high,low]" will be ignored if "crashkernel=size"
is specified.
2) "crashkernel=X,low" is valid only when "crashkernel=X,high" is passed
and there is enough memory to be allocated under 4G.
3) When allocating crashkernel above 4G and no "crashkernel=X,low" is
specified, a 128M low memory will be allocated automatically for
swiotlb bounce buffer.
See Documentation/admin-guide/kernel-parameters.txt for more information.
Following test cases have been performed as expected:
1) crashkernel=256M //low=256M
2) crashkernel=1G //low=1G
3) crashkernel=4G //high=4G, low=128M(default)
4) crashkernel=4G crashkernel=256M,high //high=4G, low=128M(default), high is ignored
5) crashkernel=4G crashkernel=256M,low //high=4G, low=128M(default), low is ignored
6) crashkernel=4G,high //high=4G, low=128M(default)
7) crashkernel=256M,low //low=0M, invalid
8) crashkernel=4G,high crashkernel=256M,low //high=4G, low=256M
9) crashkernel=4G,high crashkernel=4G,low //high=0M, low=0M, invalid
10) crashkernel=512M@2560M //low=512M
11) crashkernel=1G,high crashkernel=0M,low //high=1G, low=0M
Recommended usage in general:
1) In the case of small memory: crashkernel=512M
2) In the case of large memory: crashkernel=1024M,high crashkernel=128M,low
Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxx>
---
v2:
Submit information and format adjustments.
arch/loongarch/Kconfig | 3 ++
arch/loongarch/include/asm/crash_core.h | 11 ++++++
arch/loongarch/kernel/setup.c | 46 ++++++-------------------
3 files changed, 25 insertions(+), 35 deletions(-)
create mode 100644 arch/loongarch/include/asm/crash_core.h
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index ee123820a476..02060b2ac3f2 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -575,6 +575,9 @@ config ARCH_SELECTS_CRASH_DUMP
depends on CRASH_DUMP
select RELOCATABLE
+config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+ def_bool CRASH_CORE
+
config RELOCATABLE
bool "Relocatable kernel"
help
diff --git a/arch/loongarch/include/asm/crash_core.h b/arch/loongarch/include/asm/crash_core.h
new file mode 100644
index 000000000000..1f7040d8ed0f
--- /dev/null
+++ b/arch/loongarch/include/asm/crash_core.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _LOONGARCH_CRASH_CORE_H
+#define _LOONGARCH_CRASH_CORE_H
+
+#define CRASH_ALIGN SZ_2M
+
+#define CRASH_ADDR_LOW_MAX SZ_4G
+#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM()
+
+extern phys_addr_t memblock_end_of_DRAM(void);
+#endif
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index d183a745fb85..189cd9575758 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -252,38 +252,23 @@ static void __init arch_reserve_vmcore(void)
#endif
}
-/* 2MB alignment for crash kernel regions */
-#define CRASH_ALIGN SZ_2M
-#define CRASH_ADDR_MAX SZ_4G
-
-static void __init arch_parse_crashkernel(void)
+static void __init arch_reserve_crashkernel(void)
{
-#ifdef CONFIG_KEXEC
- int ret;
- unsigned long long total_mem;
+ unsigned long long low_size = 0;
unsigned long long crash_base, crash_size;
+ char *cmdline = boot_command_line;
+ bool high = false;
+ int ret;
- total_mem = memblock_phys_mem_size();
- ret = parse_crashkernel(boot_command_line, total_mem,
- &crash_size, &crash_base,
- NULL, NULL);
- if (ret < 0 || crash_size <= 0)
+ if (!IS_ENABLED(CONFIG_KEXEC_CORE))
return;
- if (crash_base <= 0) {
- crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, CRASH_ALIGN, CRASH_ADDR_MAX);
- if (!crash_base) {
- pr_warn("crashkernel reservation failed - No suitable area found.\n");
- return;
- }
- } else if (!memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, crash_base + crash_size)) {
- pr_warn("Invalid memory region reserved for crash kernel\n");
+ ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
+ &crash_size, &crash_base, &low_size, &high);
+ if (ret)
return;
- }
- crashk_res.start = crash_base;
- crashk_res.end = crash_base + crash_size - 1;
-#endif
+ reserve_crashkernel_generic(cmdline, crash_size, crash_base, low_size, high);
}
static void __init fdt_setup(void)
@@ -357,7 +342,7 @@ static void __init bootcmdline_init(char **cmdline_p)
void __init platform_init(void)
{
arch_reserve_vmcore();
- arch_parse_crashkernel();
+ arch_reserve_crashkernel();
#ifdef CONFIG_ACPI_TABLE_UPGRADE
acpi_table_upgrade();
@@ -467,15 +452,6 @@ static void __init resource_init(void)
request_resource(res, &data_resource);
request_resource(res, &bss_resource);
}
-
-#ifdef CONFIG_KEXEC
- if (crashk_res.start < crashk_res.end) {
- insert_resource(&iomem_resource, &crashk_res);
- pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
- (unsigned long)((crashk_res.end - crashk_res.start + 1) >> 20),
- (unsigned long)(crashk_res.start >> 20));
- }
-#endif
}
static int __init add_legacy_isa_io(struct fwnode_handle *fwnode,
--
2.40.0
