spapr: introduce SpaprMachineState::numa_assoc_array

The next step to centralize all NUMA/associativity handling in
the spapr machine is to create a 'one stop place' for all
things ibm,associativity.

This patch introduces numa_assoc_array, a 2 dimensional array
that will store all ibm,associativity arrays of all NUMA nodes.
This array is initialized in a new spapr_numa_associativity_init()
function, called in spapr_machine_init(). It is being initialized
with the same values used in other ibm,associativity properties
around spapr files (i.e. all zeros, last value is node_id).
The idea is to remove all hardcoded definitions and FDT writes
of ibm,associativity arrays, doing instead a call to the new
helper spapr_numa_write_associativity_dt() helper, that will
be able to write the DT with the correct values.

We'll start small, handling the trivial cases first. The
remaining instances of ibm,associativity will be handled
next.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20200903220639.563090-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 30 insertions, 0 deletions

diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c
index cdf3288..f6b6fe6 100644
--- a/hw/ppc/spapr_numa.c
+++ b/hw/ppc/spapr_numa.c
@@ -15,6 +15,36 @@
 #include "hw/ppc/spapr_numa.h"
 #include "hw/ppc/fdt.h"
 
+
+void spapr_numa_associativity_init(SpaprMachineState *spapr,
+                                   MachineState *machine)
+{
+    int nb_numa_nodes = machine->numa_state->num_nodes;
+    int i;
+
+    /*
+     * For all associativity arrays: first position is the size,
+     * position MAX_DISTANCE_REF_POINTS is always the numa_id,
+     * represented by the index 'i'.
+     *
+     * This will break on sparse NUMA setups, when/if QEMU starts
+     * to support it, because there will be no more guarantee that
+     * 'i' will be a valid node_id set by the user.
+     */
+    for (i = 0; i < nb_numa_nodes; i++) {
+        spapr->numa_assoc_array[i][0] = cpu_to_be32(MAX_DISTANCE_REF_POINTS);
+        spapr->numa_assoc_array[i][MAX_DISTANCE_REF_POINTS] = cpu_to_be32(i);
+    }
+}
+
+void spapr_numa_write_associativity_dt(SpaprMachineState *spapr, void *fdt,
+                                       int offset, int nodeid)
+{
+    _FDT((fdt_setprop(fdt, offset, "ibm,associativity",
+                      spapr->numa_assoc_array[nodeid],
+                      sizeof(spapr->numa_assoc_array[nodeid]))));
+}
+
 /*
  * Helper that writes ibm,associativity-reference-points and
  * max-associativity-domains in the RTAS pointed by @rtas