powerpc/pseries: Update CPU maps when device tree is updated

Platform events such as partition migration or the new PRRN firmware
feature can cause the NUMA characteristics of a CPU to change, and these
changes will be reflected in the device tree nodes for the affected
CPUs.

This patch registers a handler for Open Firmware device tree updates
and reconfigures the CPU and node maps whenever the associativity
changes. Currently, this is accomplished by marking the affected CPUs in
the cpu_associativity_changes_mask and allowing
arch_update_cpu_topology() to retrieve the new associativity information
using hcall_vphn().

Protecting the NUMA cpu maps from concurrent access during an update
operation will be addressed in a subsequent patch in this series.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 3 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/firmware.h b/arch/powerpc/include/asm/firmware.h
index 6e336e0978b1..0df54646f968 100644
--- a/arch/powerpc/include/asm/firmware.h
+++ b/arch/powerpc/include/asm/firmware.h
@@ -51,6 +51,7 @@
 #define FW_FEATURE_SET_MODE     ASM_CONST(0x0000000040000000)
 #define FW_FEATURE_BEST_ENERGY  ASM_CONST(0x0000000080000000)
 #define FW_FEATURE_TYPE1_AFFINITY ASM_CONST(0x0000000100000000)
+#define FW_FEATURE_PRRN         ASM_CONST(0x0000000200000000)
 
 #ifndef __ASSEMBLY__
 
@@ -66,7 +67,7 @@ enum {
                 FW_FEATURE_MULTITCE | FW_FEATURE_SPLPAR | FW_FEATURE_LPAR |
                 FW_FEATURE_CMO | FW_FEATURE_VPHN | FW_FEATURE_XCMO |
                 FW_FEATURE_SET_MODE | FW_FEATURE_BEST_ENERGY |
-                FW_FEATURE_TYPE1_AFFINITY,
+                FW_FEATURE_TYPE1_AFFINITY | FW_FEATURE_PRRN,
         FW_FEATURE_PSERIES_ALWAYS = 0,
         FW_FEATURE_POWERNV_POSSIBLE = FW_FEATURE_OPAL | FW_FEATURE_OPALv2,
         FW_FEATURE_POWERNV_ALWAYS = 0,
diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
index 2ea8b856d605..bc2da154f68b 100644
--- a/arch/powerpc/include/asm/prom.h
+++ b/arch/powerpc/include/asm/prom.h
@@ -128,6 +128,7 @@ struct of_drconf_cell {
 #define OV5_CMO                 0x0480  /* Cooperative Memory Overcommitment */
 #define OV5_XCMO                0x0440  /* Page Coalescing */
 #define OV5_TYPE1_AFFINITY      0x0580  /* Type 1 NUMA affinity */
+#define OV5_PRRN                0x0540  /* Platform Resource Reassignment */
 #define OV5_PFO_HW_RNG          0x0E80  /* PFO Random Number Generator */
 #define OV5_PFO_HW_842          0x0E40  /* PFO Compression Accelerator */
 #define OV5_PFO_HW_ENCR         0x0E20  /* PFO Encryption Accelerator */