powerpc/pseries: Update LMB associativity index during DLPAR add/remove

The associativity array index specified for a LMB in the device tree,
/ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory, needs to be updated
prior to DLPAR adding a LMB and after DLPAR removing a LMB.

Without doing this step in the DLPAR add process a LMB could be configured
with the incorrect affinity. For a LMB that was not present at boot the
affinity index is set to 0xffffffff, which defaults to adding the LMB to
the first online node since the index is not a valid value. Or, the
affinity index could contain a stale value if the LMB was present at boot
but later DLPAR removed and is being DLPAR added back to the system.

This patch adds a step in the DLPAR add flow to look up the associativity
index for a LMB prior to adding a LMB and setting the associativity to
0xffffffff when a LMB is removed.

This patch also modifies the DLPAR add/remove flow to no longer do a single
update of the device tree property after all of the requested DLPAR
operations are complete and now does a property update during the add
or remove of each LMB.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 294acfd..2ce1385 100644 (file)
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -116,6 +116,155 @@ static struct property *dlpar_clone_drconf_property(struct device_node *dn)
        return new_prop;
 }
 
+static void dlpar_update_drconf_property(struct device_node *dn,
+                                        struct property *prop)
+{
+       struct of_drconf_cell *lmbs;
+       u32 num_lmbs, *p;
+       int i;
+
+       /* Convert the property back to BE */
+       p = prop->value;
+       num_lmbs = *p;
+       *p = cpu_to_be32(*p);
+       p++;
+
+       lmbs = (struct of_drconf_cell *)p;
+       for (i = 0; i < num_lmbs; i++) {
+               lmbs[i].base_addr = cpu_to_be64(lmbs[i].base_addr);
+               lmbs[i].drc_index = cpu_to_be32(lmbs[i].drc_index);
+               lmbs[i].flags = cpu_to_be32(lmbs[i].flags);
+       }
+
+       rtas_hp_event = true;
+       of_update_property(dn, prop);
+       rtas_hp_event = false;
+}
+
+static int dlpar_update_device_tree_lmb(struct of_drconf_cell *lmb)
+{
+       struct device_node *dn;
+       struct property *prop;
+       struct of_drconf_cell *lmbs;
+       u32 *p, num_lmbs;
+       int i;
+
+       dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+       if (!dn)
+               return -ENODEV;
+
+       prop = dlpar_clone_drconf_property(dn);
+       if (!prop) {
+               of_node_put(dn);
+               return -ENODEV;
+       }
+
+       p = prop->value;
+       num_lmbs = *p++;
+       lmbs = (struct of_drconf_cell *)p;
+
+       for (i = 0; i < num_lmbs; i++) {
+               if (lmbs[i].drc_index == lmb->drc_index) {
+                       lmbs[i].flags = lmb->flags;
+                       lmbs[i].aa_index = lmb->aa_index;
+
+                       dlpar_update_drconf_property(dn, prop);
+                       break;
+               }
+       }
+
+       of_node_put(dn);
+       return 0;
+}
+
+static u32 lookup_lmb_associativity_index(struct of_drconf_cell *lmb)
+{
+       struct device_node *parent, *lmb_node, *dr_node;
+       const u32 *lmb_assoc;
+       const u32 *assoc_arrays;
+       u32 aa_index;
+       int aa_arrays, aa_array_entries, aa_array_sz;
+       int i;
+
+       parent = of_find_node_by_path("/");
+       if (!parent)
+               return -ENODEV;
+
+       lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
+                                            parent);
+       of_node_put(parent);
+       if (!lmb_node)
+               return -EINVAL;
+
+       lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
+       if (!lmb_assoc) {
+               dlpar_free_cc_nodes(lmb_node);
+               return -ENODEV;
+       }
+
+       dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+       if (!dr_node) {
+               dlpar_free_cc_nodes(lmb_node);
+               return -ENODEV;
+       }
+
+       assoc_arrays = of_get_property(dr_node,
+                                      "ibm,associativity-lookup-arrays",
+                                      NULL);
+       of_node_put(dr_node);
+       if (!assoc_arrays) {
+               dlpar_free_cc_nodes(lmb_node);
+               return -ENODEV;
+       }
+
+       /* The ibm,associativity-lookup-arrays property is defined to be
+        * a 32-bit value specifying the number of associativity arrays
+        * followed by a 32-bitvalue specifying the number of entries per
+        * array, followed by the associativity arrays.
+        */
+       aa_arrays = be32_to_cpu(assoc_arrays[0]);
+       aa_array_entries = be32_to_cpu(assoc_arrays[1]);
+       aa_array_sz = aa_array_entries * sizeof(u32);
+
+       aa_index = -1;
+       for (i = 0; i < aa_arrays; i++) {
+               int indx = (i * aa_array_entries) + 2;
+
+               if (memcmp(&assoc_arrays[indx], &lmb_assoc[1], aa_array_sz))
+                       continue;
+
+               aa_index = i;
+               break;
+       }
+
+       dlpar_free_cc_nodes(lmb_node);
+       return aa_index;
+}
+
+static int dlpar_add_device_tree_lmb(struct of_drconf_cell *lmb)
+{
+       int aa_index;
+
+       lmb->flags |= DRCONF_MEM_ASSIGNED;
+
+       aa_index = lookup_lmb_associativity_index(lmb);
+       if (aa_index < 0) {
+               pr_err("Couldn't find associativity index for drc index %x\n",
+                      lmb->drc_index);
+               return aa_index;
+       }
+
+       lmb->aa_index = aa_index;
+       return dlpar_update_device_tree_lmb(lmb);
+}
+
+static int dlpar_remove_device_tree_lmb(struct of_drconf_cell *lmb)
+{
+       lmb->flags &= ~DRCONF_MEM_ASSIGNED;
+       lmb->aa_index = 0xffffffff;
+       return dlpar_update_device_tree_lmb(lmb);
+}
+
 static struct memory_block *lmb_to_memblock(struct of_drconf_cell *lmb)
 {
        unsigned long section_nr;
@@ -243,8 +392,8 @@ static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
        memblock_remove(lmb->base_addr, block_sz);
 
        dlpar_release_drc(lmb->drc_index);
+       dlpar_remove_device_tree_lmb(lmb);
 
-       lmb->flags &= ~DRCONF_MEM_ASSIGNED;
        return 0;
 }
 
@@ -435,9 +584,19 @@ static int dlpar_add_lmb(struct of_drconf_cell *lmb)
        if (rc)
                return rc;
 
+       rc = dlpar_add_device_tree_lmb(lmb);
+       if (rc) {
+               pr_err("Couldn't update device tree for drc index %x\n",
+                      lmb->drc_index);
+               dlpar_release_drc(lmb->drc_index);
+               return rc;
+       }
+
        rc = dlpar_add_lmb_memory(lmb);
-       if (rc)
+       if (rc) {
+               dlpar_remove_device_tree_lmb(lmb);
                dlpar_release_drc(lmb->drc_index);
+       }
 
        return rc;
 }
@@ -542,31 +701,6 @@ static int dlpar_memory_add_by_index(u32 drc_index, struct property *prop)
        return rc;
 }
 
-static void dlpar_update_drconf_property(struct device_node *dn,
-                                        struct property *prop)
-{
-       struct of_drconf_cell *lmbs;
-       u32 num_lmbs, *p;
-       int i;
-
-       /* Convert the property back to BE */
-       p = prop->value;
-       num_lmbs = *p;
-       *p = cpu_to_be32(*p);
-       p++;
-
-       lmbs = (struct of_drconf_cell *)p;
-       for (i = 0; i < num_lmbs; i++) {
-               lmbs[i].base_addr = cpu_to_be64(lmbs[i].base_addr);
-               lmbs[i].drc_index = cpu_to_be32(lmbs[i].drc_index);
-               lmbs[i].flags = cpu_to_be32(lmbs[i].flags);
-       }
-
-       rtas_hp_event = true;
-       of_update_property(dn, prop);
-       rtas_hp_event = false;
-}
-
 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 {
        struct device_node *dn;
@@ -614,10 +748,7 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
                break;
        }
 
-       if (rc)
-               dlpar_free_drconf_property(prop);
-       else
-               dlpar_update_drconf_property(dn, prop);
+       dlpar_free_drconf_property(prop);
 
 dlpar_memory_out:
        of_node_put(dn);