ppc: introducing spapr_numa.c NUMA code helper

We're going to make changes in how spapr handles all
ibm,associativity* related properties to enhance our current NUMA
support.

At this moment we have associativity code scattered all around
spapr_* files, with hardcoded values and array sizes. This
makes it harder to change any NUMA specific parameters in
the future. Having everything in the same place allows not
only for easier tuning, but also easier understanding since all
NUMA related code is on the same file.

This patch introduces a new file to gather all NUMA/associativity
handling code in spapr, spapr_numa.c. To get things started, let's
remove associativity-reference-points and max-associativity-domains
code from spapr_dt_rtas() to a new helper called spapr_numa_write_rtas_dt().
This will decouple spapr_dt_rtas() from the NUMA changes that
are going to happen in those two properties.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20200901125645.118026-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/meson.build

@@ -25,7 +25,8 @@ ppc_ss.add(when: 'CONFIG_PSERIES', if_true: files(
   'spapr_irq.c',
   'spapr_tpm_proxy.c',
   'spapr_nvdimm.c',
-  'spapr_rtas_ddw.c'
+  'spapr_rtas_ddw.c',
+  'spapr_numa.c',
 ))
 ppc_ss.add(when: 'CONFIG_SPAPR_RNG', if_true: files('spapr_rng.c'))
 ppc_ss.add(when: ['CONFIG_PSERIES', 'CONFIG_LINUX'], if_true: files(

hw/ppc/spapr.c

@@ -81,6 +81,7 @@
 #include "hw/mem/memory-device.h"
 #include "hw/ppc/spapr_tpm_proxy.h"
 #include "hw/ppc/spapr_nvdimm.h"
+#include "hw/ppc/spapr_numa.h"
 
 #include "monitor/monitor.h"
 
@@ -891,16 +892,9 @@ static int spapr_dt_rng(void *fdt)
 static void spapr_dt_rtas(SpaprMachineState *spapr, void *fdt)
 {
     MachineState *ms = MACHINE(spapr);
-    SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(ms);
     int rtas;
     GString *hypertas = g_string_sized_new(256);
     GString *qemu_hypertas = g_string_sized_new(256);
-    uint32_t refpoints[] = {
-        cpu_to_be32(0x4),
-        cpu_to_be32(0x4),
-        cpu_to_be32(0x2),
-    };
-    uint32_t nr_refpoints = ARRAY_SIZE(refpoints);
     uint64_t max_device_addr = MACHINE(spapr)->device_memory->base +
         memory_region_size(&MACHINE(spapr)->device_memory->mr);
     uint32_t lrdr_capacity[] = {
@@ -910,14 +904,6 @@ static void spapr_dt_rtas(SpaprMachineState *spapr, void *fdt)
         cpu_to_be32(SPAPR_MEMORY_BLOCK_SIZE & 0xffffffff),
         cpu_to_be32(ms->smp.max_cpus / ms->smp.threads),
     };
-    uint32_t maxdomain = cpu_to_be32(spapr->gpu_numa_id > 1 ? 1 : 0);
-    uint32_t maxdomains[] = {
-        cpu_to_be32(4),
-        maxdomain,
-        maxdomain,
-        maxdomain,
-        cpu_to_be32(spapr->gpu_numa_id),
-    };
 
     _FDT(rtas = fdt_add_subnode(fdt, 0, "rtas"));
 
@@ -953,15 +939,7 @@ static void spapr_dt_rtas(SpaprMachineState *spapr, void *fdt)
                      qemu_hypertas->str, qemu_hypertas->len));
     g_string_free(qemu_hypertas, TRUE);
 
-    if (smc->pre_5_1_assoc_refpoints) {
+    spapr_numa_write_rtas_dt(spapr, fdt, rtas);
-        nr_refpoints = 2;
-    }
-
-    _FDT(fdt_setprop(fdt, rtas, "ibm,associativity-reference-points",
-                     refpoints, nr_refpoints * sizeof(refpoints[0])));
-
-    _FDT(fdt_setprop(fdt, rtas, "ibm,max-associativity-domains",
-                     maxdomains, sizeof(maxdomains)));
 
     /*
      * FWNMI reserves RTAS_ERROR_LOG_MAX for the machine check error log,

hw/ppc/spapr_numa.c

@@ -0,0 +1,50 @@
+/*
+ * QEMU PowerPC pSeries Logical Partition NUMA associativity handling
+ *
+ * Copyright IBM Corp. 2020
+ *
+ * Authors:
+ *  Daniel Henrique Barboza      <danielhb413@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "hw/ppc/spapr_numa.h"
+#include "hw/ppc/fdt.h"
+
+/*
+ * Helper that writes ibm,associativity-reference-points and
+ * max-associativity-domains in the RTAS pointed by @rtas
+ * in the DT @fdt.
+ */
+void spapr_numa_write_rtas_dt(SpaprMachineState *spapr, void *fdt, int rtas)
+{
+    SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
+    uint32_t refpoints[] = {
+        cpu_to_be32(0x4),
+        cpu_to_be32(0x4),
+        cpu_to_be32(0x2),
+    };
+    uint32_t nr_refpoints = ARRAY_SIZE(refpoints);
+    uint32_t maxdomain = cpu_to_be32(spapr->gpu_numa_id > 1 ? 1 : 0);
+    uint32_t maxdomains[] = {
+        cpu_to_be32(4),
+        maxdomain,
+        maxdomain,
+        maxdomain,
+        cpu_to_be32(spapr->gpu_numa_id),
+    };
+
+    if (smc->pre_5_1_assoc_refpoints) {
+        nr_refpoints = 2;
+    }
+
+    _FDT(fdt_setprop(fdt, rtas, "ibm,associativity-reference-points",
+                     refpoints, nr_refpoints * sizeof(refpoints[0])));
+
+    _FDT(fdt_setprop(fdt, rtas, "ibm,max-associativity-domains",
+                     maxdomains, sizeof(maxdomains)));
+}

include/hw/ppc/spapr_numa.h

@@ -0,0 +1,20 @@
+/*
+ * QEMU PowerPC pSeries Logical Partition NUMA associativity handling
+ *
+ * Copyright IBM Corp. 2020
+ *
+ * Authors:
+ *  Daniel Henrique Barboza      <danielhb413@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_SPAPR_NUMA_H
+#define HW_SPAPR_NUMA_H
+
+#include "hw/ppc/spapr.h"
+
+void spapr_numa_write_rtas_dt(SpaprMachineState *spapr, void *fdt, int rtas);
+
+#endif /* HW_SPAPR_NUMA_H */