[PATCH 3/3] ARM: Use generic interface to simplify crashkernel reservation

Jinjie Ruan
2024-07-08T13:29:52Z

Currently, x86, arm64, riscv and loongarch has been switched to generic
crashkernel reservation. With the help of function parse_crashkernel()
and generic reserve_crashkernel_generic(), arm32 crashkernel reservation
can also be simplified by steps:

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

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

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

The old reserve_crashkernel() can be removed.

Following test cases have been performed as expected on QEMU vexpress-a9
(1GB system memory):

1) crashkernel=4G,high // invalid
2) crashkernel=1G,high // invalid
3) crashkernel=1G,high crashkernel=0M,low // invalid
4) crashkernel=256M,high // invalid
5) crashkernel=256M,low // invalid
6) crashkernel=256M crashkernel=256M,high // high is ignored, ok
7) crashkernel=256M crashkernel=256M,low // low is ignored, ok
8) crashkernel=256M,high crashkernel=256M,low // invalid
9) crashkernel=256M,high crashkernel=4G,low // invalid
10) crashkernel=256M // ok
11) crashkernel=512M // ok
12) crashkernel=256M@0x88000000 // ok
13) crashkernel=256M@0x78000000 // ok
14) crashkernel=512M@0x78000000 // ok

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/arm/Kconfig | 3 ++
arch/arm/include/asm/crash_reserve.h | 24 +++++++++++
arch/arm/kernel/setup.c | 62 ++++------------------------
3 files changed, 36 insertions(+), 53 deletions(-)
create mode 100644 arch/arm/include/asm/crash_reserve.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 68990e1645d5..02e620e185c0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1596,6 +1596,9 @@ config ATAGS_PROC
config ARCH_SUPPORTS_CRASH_DUMP
def_bool y

+config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+ def_bool CRASH_RESERVE
+
config AUTO_ZRELADDR
bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
diff --git a/arch/arm/include/asm/crash_reserve.h b/arch/arm/include/asm/crash_reserve.h
new file mode 100644
index 000000000000..85c9298bd3b7
--- /dev/null
+++ b/arch/arm/include/asm/crash_reserve.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ARM_CRASH_RESERVE_H
+#define _ARM_CRASH_RESERVE_H
+
+/*
+ * The crash region must be aligned to 128MB to avoid
+ * zImage relocating below the reserved region.
+ */
+#define CRASH_ALIGN (128 << 20)
+
+#define CRASH_ADDR_LOW_MAX crash_addr_low_max()
+#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM()
+
+static inline unsigned long crash_addr_low_max(void)
+{
+ unsigned long long crash_max = idmap_to_phys((u32)~0);
+ unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
+
+ return (crash_max > lowmem_max) ? lowmem_max : crash_max;
+}
+
+
+#define HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
+#endif
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 59e1a13b5cf6..3a8b6f08f4ec 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -979,13 +979,6 @@ static int __init init_machine_late(void)
}
late_initcall(init_machine_late);

-#ifdef CONFIG_CRASH_RESERVE
-/*
- * The crash region must be aligned to 128MB to avoid
- * zImage relocating below the reserved region.
- */
-#define CRASH_ALIGN (128 << 20)
-
static inline unsigned long long get_total_mem(void)
{
unsigned long total;
@@ -994,61 +987,27 @@ static inline unsigned long long get_total_mem(void)
return total << PAGE_SHIFT;
}

-/**
- * reserve_crashkernel() - reserves memory are for crash kernel
- *
- * This function reserves memory area given in "crashkernel=" kernel command
- * line parameter. The memory reserved is used by a 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_size, crash_base;
+ unsigned long long low_size = 0;
unsigned long long total_mem;
+ bool high = false;
int ret;

+ if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
+ return;
+
total_mem = get_total_mem();
ret = parse_crashkernel(boot_command_line, total_mem,
&crash_size, &crash_base,
- NULL, NULL);
+ &low_size, &high);
/* invalid value specified or crashkernel=0 */
crash_size = (phys_addr_t)crash_size;
if (ret || !crash_size)
return;

- if (crash_base <= 0) {
- unsigned long long crash_max = idmap_to_phys((u32)~0);
- unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
- if (crash_max > lowmem_max)
- crash_max = lowmem_max;
-
- crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
- CRASH_ALIGN, crash_max);
- if (!crash_base) {
- pr_err("crashkernel reservation failed - No suitable area found.\n");
- return;
- }
- } else {
- unsigned long long crash_max = crash_base + crash_size;
- unsigned long long start;
-
- start = memblock_phys_alloc_range(crash_size, SECTION_SIZE,
- crash_base, crash_max);
- if (!start) {
- pr_err("crashkernel reservation failed - memory is in use.\n");
- return;
- }
- }
-
- pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
- (unsigned long)(crash_size >> 20),
- (unsigned long)(crash_base >> 20),
- (unsigned long)(total_mem >> 20));
-
- /* The crashk resource must always be located in normal mem */
- crashk_res.start = crash_base;
- crashk_res.end = crash_base + crash_size - 1;
- insert_resource(&iomem_resource, &crashk_res);
+ reserve_crashkernel_generic(boot_command_line, crash_size, crash_base, low_size, high);

if (arm_has_idmap_alias()) {
/*
@@ -1065,9 +1024,6 @@ static void __init reserve_crashkernel(void)
insert_resource(&iomem_resource, &crashk_boot_res);
}
}
-#else
-static inline void reserve_crashkernel(void) {}
-#endif /* CONFIG_CRASH_RESERVE*/

void __init hyp_mode_check(void)
{
@@ -1190,7 +1146,7 @@ void __init setup_arch(char **cmdline_p)
if (!is_smp())
hyp_mode_check();

- reserve_crashkernel();
+ arch_reserve_crashkernel();

#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
--
2.34.1