This patch adds the ability to do memory hotplug remove in the kernel.
Currently the hotplug add/remove of memory is handled by the drmgr
command. The drmgr command performs the add/remove by performing
some work in user-space and making requests to the kernel to handle
other pieces. By moving all of the work to the kernel we can do the
add and remove faster, and provide a common place to do memory hotplug
for both the PowerVM and PowerKVM environments.
Signed-off-by: Nathan Fontenot <nf...@linux.vnet.ibm.com>
---
arch/powerpc/platforms/pseries/hotplug-memory.c | 140 +++++++++++++++++++++++
1 file changed, 139 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index b254773..160c424 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -193,7 +193,137 @@ static int pseries_remove_mem_node(struct device_node *np)
pseries_remove_memblock(base, lmb_size);
return 0;
}
+
+static int lmb_is_removable(struct of_drconf_cell *lmb)
+{
+ int i, scns_per_block;
+ int rc = 1;
+ unsigned long pfn, block_sz;
+ u64 phys_addr;
+
+ phys_addr = be64_to_cpu(lmb->base_addr);
+ block_sz = memory_block_size_bytes();
+ scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
+
+ for (i = 0; i < scns_per_block; i++) {
+ pfn = PFN_DOWN(phys_addr);
+ if (!pfn_present(pfn))
+ continue;
+
+ rc &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
+ phys_addr += MIN_MEMORY_BLOCK_SIZE;
+ }
+
+ return rc;
+}
+
+static int dlpar_add_one_lmb(struct of_drconf_cell *);
+
+static int dlpar_remove_one_lmb(struct of_drconf_cell *lmb)
+{
+ struct memory_block *mem_block;
+ unsigned long block_sz;
+ u64 phys_addr;
+ int nid, rc;
+
+ block_sz = memory_block_size_bytes();
+ phys_addr = be64_to_cpu(lmb->base_addr);
+ nid = memory_add_physaddr_to_nid(phys_addr);
+
+ if (!pfn_valid(phys_addr >> PAGE_SHIFT)) {
+ memblock_remove(phys_addr, block_sz);
+ return 0;
+ }
+
+ mem_block = lmb_to_memblock(lmb);
+ if (!mem_block)
+ return -EINVAL;
+
+ rc = device_offline(&mem_block->dev);
+ put_device(&mem_block->dev);
+ if (rc)
+ return rc;
+
+ remove_memory(nid, phys_addr, block_sz);
+ memblock_remove(phys_addr, block_sz);
+
+ return 0;
+}
+
+static int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
+{
+ struct of_drconf_cell *lmb;
+ struct device_node *dn;
+ struct property *prop;
+ int lmbs_to_remove, lmbs_removed = 0;
+ int i, entries;
+ int rc = -EINVAL;
+ uint32_t *p;
+
+ if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) {
+ lmbs_to_remove = be32_to_cpu(hp_elog->_drc_u.drc_count);
+ pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
+ } else {
+ lmbs_to_remove = 1;
+ pr_info("Attempting to hot-remove LMB, drc index %x\n",
+ be32_to_cpu(hp_elog->_drc_u.drc_index));
+ }
+
+ dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+ if (!dn)
+ return -EINVAL;
+
+ prop = dlpar_clone_drconf_property(dn);
+ if (!prop) {
+ of_node_put(dn);
+ return -EINVAL;
+ }
+
+ p = prop->value;
+ entries = be32_to_cpu(*p++);
+ lmb = (struct of_drconf_cell *)p;
+
+ for (i = 0; i < entries; i++, lmb++) {
+ u32 drc_index = be32_to_cpu(lmb->drc_index);
+
+ if (lmbs_to_remove == lmbs_removed)
+ break;
+
+ if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX
+ && lmb->drc_index != hp_elog->_drc_u.drc_index)
+ continue;
+
+ if (!(be32_to_cpu(lmb->flags) & DRCONF_MEM_ASSIGNED)
+ || !lmb_is_removable(lmb))
+ continue;
+
+ rc = dlpar_remove_one_lmb(lmb);
+ if (rc)
+ continue;
+
+ rc = dlpar_release_drc(drc_index);
+ if (rc) {
+ dlpar_add_one_lmb(lmb);
+ continue;
+ }
+
+ lmb->flags &= cpu_to_be32(~DRCONF_MEM_ASSIGNED);
+ lmbs_removed++;
+ pr_info("Memory at %llx (drc index %x) has been hot-removed\n",
+ be64_to_cpu(lmb->base_addr), drc_index);
+ }
+
+ if (lmbs_removed)
+ rc = of_update_property(dn, prop);
+ else
+ dlpar_free_drconf_property(prop);
+
+ of_node_put(dn);
+ return rc ? rc : lmbs_removed;
+}
+
#else
+
static inline int pseries_remove_memblock(unsigned long base,
unsigned int memblock_size)
{
@@ -203,6 +333,11 @@ static inline int pseries_remove_mem_node(struct
device_node *np)
{
return 0;
}
+static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
+{
+ return -EOPNOTSUPP;
+}
+
#endif /* CONFIG_MEMORY_HOTREMOVE */
static int dlpar_add_one_lmb(struct of_drconf_cell *lmb)
@@ -320,7 +455,7 @@ static int dlpar_memory_add(struct pseries_hp_errorlog
*hp_elog)
int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
{
- int rc = 0;
+ int rc;
if (hp_elog->id_type != PSERIES_HP_ELOG_ID_DRC_COUNT
&& hp_elog->id_type != PSERIES_HP_ELOG_ID_DRC_INDEX)
@@ -332,6 +467,9 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
case PSERIES_HP_ELOG_ACTION_ADD:
rc = dlpar_memory_add(hp_elog);
break;
+ case PSERIES_HP_ELOG_ACTION_REMOVE:
+ rc = dlpar_memory_remove(hp_elog);
+ break;
default:
pr_err("Invalid action (%d) specified\n", hp_elog->action);
rc = -EINVAL;
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