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Commit e2ff3940 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes 



During ACPI memory hotplug configuration bind memory blocks residing
in modules removable through the standard ACPI mechanism to struct
acpi_device objects associated with ACPI namespace objects
representing those modules.  Accordingly, unbind those memory blocks
from the struct acpi_device objects when the memory modules in
question are being removed.

When "offline" operation for devices representing memory blocks is
introduced, this will allow the ACPI core's device hot-remove code to
use it to carry out remove_memory() for those memory blocks and check
the results of that before it actually removes the modules holding
them from the system.

Since walk_memory_range() is used for accessing all memory blocks
corresponding to a given ACPI namespace object, it is exported from
memory_hotplug.c so that the code in acpi_memhotplug.c can use it.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: default avatarVasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Reviewed-by: default avatarToshi Kani <toshi.kani@hp.com>
parent ac212b69

drivers/acpi/acpi_memhotplug.c

+50 −3
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
 */



#include <linux/acpi.h>

#include <linux/memory.h>

#include <linux/memory_hotplug.h>



#include "internal.h"
@@ -166,13 +167,50 @@ static int acpi_memory_check_device(struct acpi_memory_device *mem_device) 
	return 0;

}



static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)

{

	return PFN_DOWN(info->start_addr);

}



static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)

{

	return PFN_UP(info->start_addr + info->length-1);

}



static int acpi_bind_memblk(struct memory_block *mem, void *arg)

{

	return acpi_bind_one(&mem->dev, (acpi_handle)arg);

}



static int acpi_bind_memory_blocks(struct acpi_memory_info *info,

				   acpi_handle handle)

{

	return walk_memory_range(acpi_meminfo_start_pfn(info),

				 acpi_meminfo_end_pfn(info), (void *)handle,

				 acpi_bind_memblk);

}



static int acpi_unbind_memblk(struct memory_block *mem, void *arg)

{

	acpi_unbind_one(&mem->dev);

	return 0;

}



static void acpi_unbind_memory_blocks(struct acpi_memory_info *info,

				      acpi_handle handle)

{

	walk_memory_range(acpi_meminfo_start_pfn(info),

			  acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);

}



static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)

{

	acpi_handle handle = mem_device->device->handle;

	int result, num_enabled = 0;

	struct acpi_memory_info *info;

	int node;



	node = acpi_get_node(mem_device->device->handle);

	node = acpi_get_node(handle);

	/*

	 * Tell the VM there is more memory here...

	 * Note: Assume that this function returns zero on success
@@ -203,6 +241,12 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) 
		if (result && result != -EEXIST)

			continue;



		result = acpi_bind_memory_blocks(info, handle);

		if (result) {

			acpi_unbind_memory_blocks(info, handle);

			return -ENODEV;

		}



		info->enabled = 1;



		/*
@@ -229,10 +273,11 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) 


static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)

{

	acpi_handle handle = mem_device->device->handle;

	int result = 0, nid;

	struct acpi_memory_info *info, *n;



	nid = acpi_get_node(mem_device->device->handle);

	nid = acpi_get_node(handle);



	list_for_each_entry_safe(info, n, &mem_device->res_list, list) {

		if (!info->enabled)
@@ -240,6 +285,8 @@ static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) 


		if (nid < 0)

			nid = memory_add_physaddr_to_nid(info->start_addr);



		acpi_unbind_memory_blocks(info, handle);

		result = remove_memory(nid, info->start_addr, info->length);

		if (result)

			return result;
@@ -300,7 +347,7 @@ static int acpi_memory_device_add(struct acpi_device *device, 
	if (result) {

		dev_err(&device->dev, "acpi_memory_enable_device() error\n");

		acpi_memory_device_free(mem_device);

		return -ENODEV;

		return result;

	}



	dev_dbg(&device->dev, "Memory device configured by ACPI\n");

include/linux/memory_hotplug.h

+2 −0
Original line number Diff line number Diff line
@@ -245,6 +245,8 @@ static inline int is_mem_section_removable(unsigned long pfn, 
static inline void try_offline_node(int nid) {}

#endif /* CONFIG_MEMORY_HOTREMOVE */



extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,

		void *arg, int (*func)(struct memory_block *, void *));

extern int mem_online_node(int nid);

extern int add_memory(int nid, u64 start, u64 size);

extern int arch_add_memory(int nid, u64 start, u64 size);

mm/memory_hotplug.c

+3 −1
Original line number Diff line number Diff line
@@ -1618,6 +1618,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) 
{

	return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);

}

#endif /* CONFIG_MEMORY_HOTREMOVE */



/**

 * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
@@ -1631,7 +1632,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) 
 *

 * Returns the return value of func.

 */

static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,

int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,

		void *arg, int (*func)(struct memory_block *, void *))

{

	struct memory_block *mem = NULL;
@@ -1668,6 +1669,7 @@ static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, 
	return 0;

}



#ifdef CONFIG_MEMORY_HOTREMOVE

/**

 * offline_memory_block_cb - callback function for offlining memory block

 * @mem: the memory block to be offlined