[PATCH] powerpc/pseries Use remove_memory() to remove memory
Nathan Fontenot
nfont at linux.vnet.ibm.com
Tue Jan 28 03:54:06 EST 2014
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: Nathan Fontenot <nfont at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/machdep.h | 4 +
arch/powerpc/mm/mem.c | 7 +
arch/powerpc/platforms/pseries/hotplug-memory.c | 85 +++++++++++-------------
3 files changed, 50 insertions(+), 46 deletions(-)
Index: powerpc/arch/powerpc/platforms/pseries/hotplug-memory.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/hotplug-memory.c 2014-01-27 08:47:19.000000000 -0600
+++ powerpc/arch/powerpc/platforms/pseries/hotplug-memory.c 2014-01-27 09:21:54.000000000 -0600
@@ -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 @@
}
#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 @@
return 0;
}
- zone = page_zone(pfn_to_page(start_pfn));
-
- /*
- * 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;
+ block_sz = memory_block_size_bytes();
+ sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
+ nid = memory_add_physaddr_to_nid(base);
+
+ 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 @@
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 @@
{
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 @@
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 @@
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);
Index: powerpc/arch/powerpc/include/asm/machdep.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/machdep.h 2014-01-27 08:47:18.000000000 -0600
+++ powerpc/arch/powerpc/include/asm/machdep.h 2014-01-27 08:48:31.000000000 -0600
@@ -279,6 +279,10 @@
#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);
Index: powerpc/arch/powerpc/mm/mem.c
===================================================================
--- powerpc.orig/arch/powerpc/mm/mem.c 2014-01-27 08:47:18.000000000 -0600
+++ powerpc/arch/powerpc/mm/mem.c 2014-01-27 08:48:31.000000000 -0600
@@ -139,9 +139,14 @@
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 */
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