Commit e3185ee4 authored by Sourabh Jain's avatar Sourabh Jain Committed by Andrew Morton
Browse files

powerpc/crash: use generic crashkernel reservation 

Commit 0ab97169 ("crash_core: add generic function to do reservation")
added a generic function to reserve crashkernel memory.  So let's use the
same function on powerpc and remove the architecture-specific code that
essentially does the same thing.

The generic crashkernel reservation also provides a way to split the
crashkernel reservation into high and low memory reservations, which can
be enabled for powerpc in the future.

Along with moving to the generic crashkernel reservation, the code related
to finding the base address for the crashkernel has been separated into
its own function name get_crash_base() for better readability and
maintainability.

Link: https://lkml.kernel.org/r/20250131113830.925179-8-sourabhjain@linux.ibm.com


Signed-off-by: default avatarSourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: default avatarMahesh Salgaonkar <mahesh@linux.ibm.com>
Acked-by: default avatarHari Bathini <hbathini@linux.ibm.com>
Cc: Baoquan he <bhe@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent bce074bd

arch/powerpc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -721,6 +721,9 @@ config ARCH_SUPPORTS_CRASH_HOTPLUG 
	def_bool y

	depends on PPC64



config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION

	def_bool CRASH_RESERVE



config FA_DUMP

	bool "Firmware-assisted dump"

	depends on CRASH_DUMP && PPC64 && (PPC_RTAS || PPC_POWERNV)

arch/powerpc/include/asm/crash_reserve.h

0 → 100644
+8 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_POWERPC_CRASH_RESERVE_H

#define _ASM_POWERPC_CRASH_RESERVE_H



/* crash kernel regions are Page size agliged */

#define CRASH_ALIGN             PAGE_SIZE



#endif /* _ASM_POWERPC_CRASH_RESERVE_H */

arch/powerpc/include/asm/kexec.h

+2 −2
Original line number Diff line number Diff line
@@ -114,9 +114,9 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, struct crash_mem 


#ifdef CONFIG_CRASH_RESERVE

int __init overlaps_crashkernel(unsigned long start, unsigned long size);

extern void reserve_crashkernel(void);

extern void arch_reserve_crashkernel(void);

#else

static inline void reserve_crashkernel(void) {}

static inline void arch_reserve_crashkernel(void) {}

static inline int overlaps_crashkernel(unsigned long start, unsigned long size) { return 0; }

#endif

arch/powerpc/kernel/prom.c

+1 −1
Original line number Diff line number Diff line
@@ -860,7 +860,7 @@ void __init early_init_devtree(void *params) 
	 */

	if (fadump_reserve_mem() == 0)

#endif

		reserve_crashkernel();

		arch_reserve_crashkernel();

	early_reserve_mem();



	if (memory_limit > memblock_phys_mem_size())

arch/powerpc/kexec/core.c

+39 −51
Original line number Diff line number Diff line
@@ -58,38 +58,20 @@ void machine_kexec(struct kimage *image) 
}



#ifdef CONFIG_CRASH_RESERVE

void __init reserve_crashkernel(void)

{

	unsigned long long crash_size, crash_base, total_mem_sz;

	int ret;



	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();

	/* use common parsing */

	ret = parse_crashkernel(boot_command_line, total_mem_sz,

			&crash_size, &crash_base, NULL, NULL);

	if (ret == 0 && crash_size > 0) {

		crashk_res.start = crash_base;

		crashk_res.end = crash_base + crash_size - 1;

	}



	if (crashk_res.end == crashk_res.start) {

		crashk_res.start = crashk_res.end = 0;

		return;

	}



	/* We might have got these values via the command line or the

	 * device tree, either way sanitise them now. */



	crash_size = resource_size(&crashk_res);

static unsigned long long __init get_crash_base(unsigned long long crash_base)

{



#ifndef CONFIG_NONSTATIC_KERNEL

	if (crashk_res.start != KDUMP_KERNELBASE)

	if (crash_base != KDUMP_KERNELBASE)

		printk("Crash kernel location must be 0x%x\n",

				KDUMP_KERNELBASE);



	crashk_res.start = KDUMP_KERNELBASE;

	return KDUMP_KERNELBASE;

#else

	if (!crashk_res.start) {

	unsigned long long crash_base_align;



	if (!crash_base) {

#ifdef CONFIG_PPC64

		/*

		 * On the LPAR platform place the crash kernel to mid of
@@ -101,45 +83,51 @@ void __init reserve_crashkernel(void) 
		 * kernel starts at 128MB offset on other platforms.

		 */

		if (firmware_has_feature(FW_FEATURE_LPAR))

			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M);

			crash_base = min_t(u64, ppc64_rma_size / 2, SZ_512M);

		else

			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M);

			crash_base = min_t(u64, ppc64_rma_size / 2, SZ_128M);

#else

		crashk_res.start = KDUMP_KERNELBASE;

		crash_base = KDUMP_KERNELBASE;

#endif

	}



	crash_base = PAGE_ALIGN(crashk_res.start);

	if (crash_base != crashk_res.start) {

		printk("Crash kernel base must be aligned to 0x%lx\n",

				PAGE_SIZE);

		crashk_res.start = crash_base;

	}

	crash_base_align = PAGE_ALIGN(crash_base);

	if (crash_base != crash_base_align)

		pr_warn("Crash kernel base must be aligned to 0x%lx\n", PAGE_SIZE);



	return crash_base_align;

#endif

	crash_size = PAGE_ALIGN(crash_size);

	crashk_res.end = crashk_res.start + crash_size - 1;

}



	/* The crash region must not overlap the current kernel */

	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {

		printk(KERN_WARNING

			"Crash kernel can not overlap current kernel\n");

		crashk_res.start = crashk_res.end = 0;

void __init arch_reserve_crashkernel(void)

{

	unsigned long long crash_size, crash_base, crash_end;

	unsigned long long kernel_start, kernel_size;

	unsigned long long total_mem_sz;

	int ret;



	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();



	/* use common parsing */

	ret = parse_crashkernel(boot_command_line, total_mem_sz, &crash_size,

				&crash_base, NULL, NULL);



	if (ret)

		return;

	}



	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "

			"for crashkernel (System RAM: %ldMB)\n",

			(unsigned long)(crash_size >> 20),

			(unsigned long)(crashk_res.start >> 20),

			(unsigned long)(total_mem_sz >> 20));

	crash_base = get_crash_base(crash_base);

	crash_end = crash_base + crash_size - 1;



	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||

	    memblock_reserve(crashk_res.start, crash_size)) {

		pr_err("Failed to reserve memory for crashkernel!\n");

		crashk_res.start = crashk_res.end = 0;

	kernel_start = __pa(_stext);

	kernel_size = _end - _stext;



	/* The crash region must not overlap the current kernel */

	if ((kernel_start + kernel_size > crash_base) && (kernel_start <= crash_end)) {

		pr_warn("Crash kernel can not overlap current kernel\n");

		return;

	}



	reserve_crashkernel_generic(crash_size, crash_base, 0, false);

}



int __init overlaps_crashkernel(unsigned long start, unsigned long size)