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Commit 9ac8cde9 authored by Nathan Fontenot's avatar Nathan Fontenot Committed by Benjamin Herrenschmidt
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powerpc/pseries: Use remove_memory() to remove memory 



The memory remove code for powerpc/pseries should call remove_memory()
so that we are holding the hotplug_memory lock during memory remove
operations.

This patch updates the memory node remove handler to call remove_memory()
and adds a ppc_md.remove_memory() entry to handle pseries specific work
that is called from arch_remove_memory().

During memory remove in pseries_remove_memblock() we have to stay with
removing memory one section at a time. This is needed because of how memory
resources are handled. During memory add for pseries (via the probe file in
sysfs) we add memory one section at a time which gives us a memory resource
for each section. Future patches will aim to address this so will not have
to remove memory one section at a time.

Signed-off-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 22d651dc

arch/powerpc/include/asm/machdep.h

+4 −0
Original line number Diff line number Diff line
@@ -282,6 +282,10 @@ struct machdep_calls { 
#ifdef CONFIG_ARCH_RANDOM

	int (*get_random_long)(unsigned long *v);

#endif



#ifdef CONFIG_MEMORY_HOTREMOVE

	int (*remove_memory)(u64, u64);

#endif

};



extern void e500_idle(void);

arch/powerpc/mm/mem.c

+6 −1
Original line number Diff line number Diff line
@@ -139,9 +139,14 @@ int arch_remove_memory(u64 start, u64 size) 
	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;

	int ret;



	zone = page_zone(pfn_to_page(start_pfn));

	return __remove_pages(zone, start_pfn, nr_pages);

	ret = __remove_pages(zone, start_pfn, nr_pages);

	if (!ret && (ppc_md.remove_memory))

		ret = ppc_md.remove_memory(start, size);



	return ret;

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */

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

+39 −44
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/memblock.h>

#include <linux/vmalloc.h>

#include <linux/memory.h>

#include <linux/memory_hotplug.h>



#include <asm/firmware.h>

#include <asm/machdep.h>
@@ -75,13 +76,27 @@ unsigned long memory_block_size_bytes(void) 
}



#ifdef CONFIG_MEMORY_HOTREMOVE

static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)

static int pseries_remove_memory(u64 start, u64 size)

{

	unsigned long start, start_pfn;

	struct zone *zone;

	int ret;

	unsigned long section;

	unsigned long sections_to_remove;



	/* Remove htab bolted mappings for this section of memory */

	start = (unsigned long)__va(start);

	ret = remove_section_mapping(start, start + size);



	/* Ensure all vmalloc mappings are flushed in case they also

	 * hit that section of memory

	 */

	vm_unmap_aliases();



	return ret;

}



static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)

{

	unsigned long block_sz, start_pfn;

	int sections_per_block;

	int i, nid;



	start_pfn = base >> PAGE_SHIFT;
@@ -90,45 +105,21 @@ static int pseries_remove_memblock(unsigned long base, unsigned int memblock_siz 
		return 0;

	}



	zone = page_zone(pfn_to_page(start_pfn));

	block_sz = memory_block_size_bytes();

	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;

	nid = memory_add_physaddr_to_nid(base);



	/*

	 * Remove section mappings and sysfs entries for the

	 * section of the memory we are removing.

	 *

	 * NOTE: Ideally, this should be done in generic code like

	 * remove_memory(). But remove_memory() gets called by writing

	 * to sysfs "state" file and we can't remove sysfs entries

	 * while writing to it. So we have to defer it to here.

	 */

	sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;

	for (section = 0; section < sections_to_remove; section++) {

		unsigned long pfn = start_pfn + section * PAGES_PER_SECTION;

		ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);

		if (ret)

			return ret;

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

		remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);

		base += MIN_MEMORY_BLOCK_SIZE;

	}



	/*

	 * Update memory regions for memory remove

	 */

	/* Update memory regions for memory remove */

	memblock_remove(base, memblock_size);



	/*

	 * Remove htab bolted mappings for this section of memory

	 */

	start = (unsigned long)__va(base);

	ret = remove_section_mapping(start, start + memblock_size);



	/* Ensure all vmalloc mappings are flushed in case they also

	 * hit that section of memory

	 */

	vm_unmap_aliases();



	return ret;

	return 0;

}



static int pseries_remove_memory(struct device_node *np)

static int pseries_remove_mem_node(struct device_node *np)

{

	const char *type;

	const unsigned int *regs;
@@ -153,8 +144,8 @@ static int pseries_remove_memory(struct device_node *np) 
	base = *(unsigned long *)regs;

	lmb_size = regs[3];



	ret = pseries_remove_memblock(base, lmb_size);

	return ret;

	pseries_remove_memblock(base, lmb_size);

	return 0;

}

#else

static inline int pseries_remove_memblock(unsigned long base,
@@ -162,13 +153,13 @@ static inline int pseries_remove_memblock(unsigned long base, 
{

	return -EOPNOTSUPP;

}

static inline int pseries_remove_memory(struct device_node *np)

static inline int pseries_remove_mem_node(struct device_node *np)

{

	return -EOPNOTSUPP;

}

#endif /* CONFIG_MEMORY_HOTREMOVE */



static int pseries_add_memory(struct device_node *np)

static int pseries_add_mem_node(struct device_node *np)

{

	const char *type;

	const unsigned int *regs;
@@ -254,10 +245,10 @@ static int pseries_memory_notifier(struct notifier_block *nb, 


	switch (action) {

	case OF_RECONFIG_ATTACH_NODE:

		err = pseries_add_memory(node);

		err = pseries_add_mem_node(node);

		break;

	case OF_RECONFIG_DETACH_NODE:

		err = pseries_remove_memory(node);

		err = pseries_remove_mem_node(node);

		break;

	case OF_RECONFIG_UPDATE_PROPERTY:

		pr = (struct of_prop_reconfig *)node;
@@ -277,6 +268,10 @@ static int __init pseries_memory_hotplug_init(void) 
	if (firmware_has_feature(FW_FEATURE_LPAR))

		of_reconfig_notifier_register(&pseries_mem_nb);



#ifdef CONFIG_MEMORY_HOTREMOVE

	ppc_md.remove_memory = pseries_remove_memory;

#endif



	return 0;

}

machine_device_initcall(pseries, pseries_memory_hotplug_init);