[PATCH v4 3/3] ARM: Use generic interface to simplify crashkernel reservation

Jinjie Ruan ruanjinjie at huawei.com
Fri Jul 19 02:57:35 PDT 2024


Currently, x86, arm64, riscv and loongarch has been switched to generic
crashkernel reservation, which is also ready for 32bit system.
So 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 at 0x88000000			// ok
13) crashkernel=256M at 0x78000000			// ok
14) crashkernel=512M at 0x78000000			// ok

Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>
---
v4:
- Remove the Tested-by as suggested.
v3:
- Update the commit message.
---
 arch/arm/Kconfig                     |  3 ++
 arch/arm/include/asm/crash_reserve.h | 24 +++++++++++
 arch/arm/kernel/setup.c              | 63 ++++------------------------
 3 files changed, 36 insertions(+), 54 deletions(-)
 create mode 100644 arch/arm/include/asm/crash_reserve.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index f434afff4a2c..3f198ae63950 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1597,6 +1597,9 @@ 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 e6a857bf0ce6..fc0ada003f6d 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;
@@ -994,60 +987,25 @@ 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 crash_size, crash_base, 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 */
 	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()) {
 		/*
@@ -1064,9 +1022,6 @@ 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)
 {
@@ -1189,7 +1144,7 @@ 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




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