Commit eae0dfcc authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

powerpc/fadump: avoid holes in boot memory area when fadump is registered 



To register fadump, boot memory area - the size of low memory chunk that
is required for a kernel to boot successfully when booted with restricted
memory, is assumed to have no holes. But this memory area is currently
not protected from hot-remove operations. So, fadump could fail to
re-register after a memory hot-remove operation, if memory is removed
from boot memory area. To avoid this, ensure that memory from boot
memory area is not hot-removed when fadump is registered.

Signed-off-by: default avatarHari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: default avatarMahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent a77af552

arch/powerpc/include/asm/fadump.h

+1 −0
Original line number Diff line number Diff line
@@ -203,6 +203,7 @@ struct fad_crash_memory_ranges { 
	unsigned long long	size;

};



extern int is_fadump_boot_memory_area(u64 addr, ulong size);

extern int early_init_dt_scan_fw_dump(unsigned long node,

		const char *uname, int depth, void *data);

extern int fadump_reserve_mem(void);

arch/powerpc/kernel/fadump.c

+12 −0
Original line number Diff line number Diff line
@@ -113,6 +113,18 @@ int __init early_init_dt_scan_fw_dump(unsigned long node, 
	return 1;

}



/*

 * If fadump is registered, check if the memory provided

 * falls within boot memory area.

 */

int is_fadump_boot_memory_area(u64 addr, ulong size)

{

	if (!fw_dump.dump_registered)

		return 0;



	return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size;

}



int is_fadump_active(void)

{

	return fw_dump.dump_active;

arch/powerpc/platforms/pseries/hotplug-memory.c

+7 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <asm/machdep.h>

#include <asm/prom.h>

#include <asm/sparsemem.h>

#include <asm/fadump.h>

#include "pseries.h"



static bool rtas_hp_event;
@@ -406,6 +407,12 @@ static bool lmb_is_removable(struct of_drconf_cell *lmb) 
	scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;

	phys_addr = lmb->base_addr;



#ifdef CONFIG_FA_DUMP

	/* Don't hot-remove memory that falls in fadump boot memory area */

	if (is_fadump_boot_memory_area(phys_addr, block_sz))

		return false;

#endif



	for (i = 0; i < scns_per_block; i++) {

		pfn = PFN_DOWN(phys_addr);

		if (!pfn_present(pfn))

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