[PATCH 4/6 v5] Memory DLPAR Handling

Nathan Fontenot
2009-10-28T20:57:20Z

This adds the capability to DLPAR add and remove memory from the kernel. The
patch registers handlers for the arch-specific probe and release memory
callouts to handle addition/removal of memory to the system and the associated
device tree updates.

Signed-off-by: Nathan Fontenot <nfont at austin.ibm.com>
---

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c 2009-10-28 15:21:38.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c 2009-10-28 15:21:49.000000000 -0500
@@ -16,6 +16,10 @@
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
+#include <linux/memory_hotplug.h>
+#include <linux/sysdev.h>
+#include <linux/sysfs.h>
+

#include <asm/prom.h>
#include <asm/machdep.h>
@@ -404,11 +408,189 @@
return 0;
}

+#ifdef CONFIG_MEMORY_HOTPLUG
+
+static struct property *clone_property(struct property *old_prop)
+{
+ struct property *new_prop;
+
+ new_prop = kzalloc((sizeof *new_prop), GFP_KERNEL);
+ if (!new_prop)
+ return NULL;
+
+ new_prop->name = kstrdup(old_prop->name, GFP_KERNEL);
+ new_prop->value = kzalloc(old_prop->length + 1, GFP_KERNEL);
+ if (!new_prop->name || !new_prop->value) {
+ free_property(new_prop);
+ return NULL;
+ }
+
+ memcpy(new_prop->value, old_prop->value, old_prop->length);
+ new_prop->length = old_prop->length;
+
+ return new_prop;
+}
+
+#ifdef CONFIG_ARCH_MEMORY_PROBE
+
+int memory_probe(u64 phys_addr)
+{
+ struct device_node *dn = NULL;
+ struct property *new_prop;
+ struct property *old_prop;
+ struct of_drconf_cell *drmem;
+ const u64 *lmb_size;
+ int num_entries, i;
+ int rc = -EINVAL;
+
+ if (!phys_addr)
+ goto memory_probe_exit;
+
+ dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+ if (!dn)
+ goto memory_probe_exit;
+
+ lmb_size = of_get_property(dn, "ibm,lmb-size", NULL);
+ if (!lmb_size)
+ goto memory_probe_exit;
+
+ old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+ if (!old_prop)
+ goto memory_probe_exit;
+
+ num_entries = *(u32 *)old_prop->value;
+ drmem = (struct of_drconf_cell *)
+ ((char *)old_prop->value + sizeof(u32));
+
+ for (i = 0; i < num_entries; i++) {
+ u64 lmb_end_addr = drmem[i].base_addr + *lmb_size;
+ if (phys_addr >= drmem[i].base_addr
+ && phys_addr < lmb_end_addr)
+ break;
+ }
+
+ if (i >= num_entries)
+ goto memory_probe_exit;
+
+ if (drmem[i].flags & DRCONF_MEM_ASSIGNED) {
+ /* This lmb is already adssigned to the system, nothing to do */
+ rc = 0;
+ goto memory_probe_exit;
+ }
+
+ rc = acquire_drc(drmem[i].drc_index);
+ if (rc) {
+ rc = -EINVAL;
+ goto memory_probe_exit;
+ }
+
+ new_prop = clone_property(old_prop);
+ drmem = (struct of_drconf_cell *)
+ ((char *)new_prop->value + sizeof(u32));
+
+ drmem[i].flags |= DRCONF_MEM_ASSIGNED;
+ rc = prom_update_property(dn, new_prop, old_prop);
+ if (rc) {
+ free_property(new_prop);
+ rc = -EINVAL;
+ goto memory_probe_exit;
+ }
+
+ rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+ PSERIES_DRCONF_MEM_ADD,
+ &drmem[i].base_addr);
+ if (rc == NOTIFY_BAD) {
+ prom_update_property(dn, old_prop, new_prop);
+ release_drc(drmem[i].drc_index);
+ rc = -EINVAL;
+ } else
+ rc = 0;
+
+memory_probe_exit:
+ of_node_put(dn);
+ return rc;
+}
+
+#endif /* CONFIG_ARCH_MEMORY_PROBE */
+
+#ifdef CONFIG_ARCH_MEMORY_RELEASE
+
+static int memory_release(const char *buf, size_t count)
+{
+ unsigned long drc_index;
+ struct device_node *dn;
+ struct property *new_prop, *old_prop;
+ struct of_drconf_cell *drmem;
+ int num_entries;
+ int i;
+ int rc = -EINVAL;
+
+ rc = strict_strtoul(buf, 0, &drc_index);
+ if (rc)
+ return rc;
+
+ dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+ if (!dn)
+ return rc;
+
+ old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+ if (!old_prop)
+ goto memory_release_exit;
+
+ num_entries = *(u32 *)old_prop->value;
+ drmem = (struct of_drconf_cell *)
+ ((char *)old_prop->value + sizeof(u32));
+
+ for (i = 0; i < num_entries; i++) {
+ if (drmem[i].drc_index == drc_index)
+ break;
+ }
+
+ if (i >= num_entries)
+ goto memory_release_exit;
+
+ new_prop = clone_property(old_prop);
+ drmem = (struct of_drconf_cell *)
+ ((char *)new_prop->value + sizeof(u32));
+
+ drmem[i].flags &= ~DRCONF_MEM_ASSIGNED;
+ rc = prom_update_property(dn, new_prop, old_prop);
+ if (rc) {
+ free_property(new_prop);
+ rc = -EINVAL;
+ goto memory_release_exit;
+ }
+
+ rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+ PSERIES_DRCONF_MEM_REMOVE,
+ &drmem[i].base_addr);
+ if (rc != NOTIFY_BAD)
+ rc = release_drc(drc_index);
+
+ if (rc) {
+ prom_update_property(dn, old_prop, new_prop);
+ rc = -EINVAL;
+ }
+
+memory_release_exit:
+ of_node_put(dn);
+ return rc ? rc : count;
+}
+#endif /* CONFIG_ARCH_MEMORY_RELEASE */
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
static int pseries_dlpar_init(void)
{
if (!machine_is(pseries))
return 0;

+#ifdef CONFIG_ARCH_MEMORY_RELEASE
+ ppc_md.memory_release = memory_release;
+#endif
+#ifdef CONFIG_ARCH_MEMORY_PROBE
+ ppc_md.memory_probe = memory_probe;
+#endif
+
return 0;
}
device_initcall(pseries_dlpar_init);