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Commit dab7a7b1 authored by Michael Holzheu's avatar Michael Holzheu Committed by Martin Schwidefsky
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[S390] Add architecture code for unmapping crashkernel memory 



This patch implements the crash_map_pages() function for s390.
KEXEC_CRASH_MEM_ALIGN is set to HPAGE_SIZE, in order to support
kernel mappings that use large pages. We also use HPAGE_SIZE alignment
for CONFIG_HUGETLB_PAGE=n in order to have the same 1 MiB alignment on
all s390 systems.

Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 558df720

arch/s390/include/asm/kexec.h

+3 −0
Original line number Diff line number Diff line
@@ -36,6 +36,9 @@ 
/* Allocate one page for the pdp and the second for the code */

#define KEXEC_CONTROL_PAGE_SIZE 4096



/* Alignment of crashkernel memory */

#define KEXEC_CRASH_MEM_ALIGN HPAGE_SIZE



/* The native architecture */

#define KEXEC_ARCH KEXEC_ARCH_S390

arch/s390/kernel/machine_kexec.c

+31 −0
Original line number Diff line number Diff line
@@ -132,6 +132,37 @@ static int kdump_csum_valid(struct kimage *image) 
#endif

}



/*

 * Map or unmap crashkernel memory

 */

static void crash_map_pages(int enable)

{

	unsigned long size = resource_size(&crashk_res);



	BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||

	       size % KEXEC_CRASH_MEM_ALIGN);

	if (enable)

		vmem_add_mapping(crashk_res.start, size);

	else

		vmem_remove_mapping(crashk_res.start, size);

}



/*

 * Map crashkernel memory

 */

void crash_map_reserved_pages(void)

{

	crash_map_pages(1);

}



/*

 * Unmap crashkernel memory

 */

void crash_unmap_reserved_pages(void)

{

	crash_map_pages(0);

}



/*

 * Give back memory to hypervisor before new kdump is loaded

 */

arch/s390/kernel/setup.c

+6 −4
Original line number Diff line number Diff line
@@ -446,6 +446,7 @@ static void __init setup_resources(void) 
		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;

		switch (memory_chunk[i].type) {

		case CHUNK_READ_WRITE:

		case CHUNK_CRASHK:

			res->name = "System RAM";

			break;

		case CHUNK_READ_ONLY:
@@ -720,8 +721,8 @@ static void __init reserve_crashkernel(void) 
			       &crash_base);

	if (rc || crash_size == 0)

		return;

	crash_base = PAGE_ALIGN(crash_base);

	crash_size = PAGE_ALIGN(crash_size);

	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);

	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);

	if (register_memory_notifier(&kdump_mem_nb))

		return;

	if (!crash_base)
@@ -741,7 +742,7 @@ static void __init reserve_crashkernel(void) 
	crashk_res.start = crash_base;

	crashk_res.end = crash_base + crash_size - 1;

	insert_resource(&iomem_resource, &crashk_res);

	reserve_kdump_bootmem(crash_base, crash_size, CHUNK_READ_WRITE);

	reserve_kdump_bootmem(crash_base, crash_size, CHUNK_CRASHK);

	pr_info("Reserving %lluMB of memory at %lluMB "

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

		crash_size >> 20, crash_base >> 20, memory_end >> 20);
@@ -816,7 +817,8 @@ setup_memory(void) 
	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {

		unsigned long start_chunk, end_chunk, pfn;



		if (memory_chunk[i].type != CHUNK_READ_WRITE)

		if (memory_chunk[i].type != CHUNK_READ_WRITE &&

		    memory_chunk[i].type != CHUNK_CRASHK)

			continue;

		start_chunk = PFN_DOWN(memory_chunk[i].addr);

		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);