[Qemu-devel] [PATCH 03/12] pseries: Move XICS initialization before cpu initialization

[David Gibson <david@gibson.dropbear.id.au>]

From: Ben Herrenschmidt <benh@kernel.crashing.org>

Currently, the pseries machine initializes the cpus, then the XICS
interrupt controller.  However, to support the upcoming in-kernel XICS
implementation we will need to initialize the irq controller before the
vcpus.  This patch makes the necesssary rearrangement.  This means the
xics init code can no longer auto-detect the number of cpus ("interrupt
servers" in XICS terminology) and so we must pass that in explicitly from
the platform code.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/spapr.c |   12 +++++++-----
 hw/xics.c  |   52 +++++++++++++++++++++++-----------------------------
 hw/xics.h  |    3 ++-
 3 files changed, 32 insertions(+), 35 deletions(-)

diff --git a/hw/spapr.c b/hw/spapr.c
index eafee03..dc2349c 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -747,6 +747,11 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
         spapr->htab_shift++;
     }
 
+    /* Set up Interrupt Controller before we create the VCPUs */
+    spapr->icp = xics_system_init(smp_cpus * kvmppc_smt_threads() / smp_threads,
+                                  XICS_IRQS);
+    spapr->next_irq = XICS_IRQ_BASE;
+
     /* init CPUs */
     if (cpu_model == NULL) {
         cpu_model = kvm_enabled() ? "host" : "POWER7";
@@ -759,6 +764,8 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
         }
         env = &cpu->env;
 
+        xics_cpu_setup(spapr->icp, env);
+
         /* Set time-base frequency to 512 MHz */
         cpu_ppc_tb_init(env, TIMEBASE_FREQ);
 
@@ -798,11 +805,6 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
     }
     g_free(filename);
 
-
-    /* Set up Interrupt Controller */
-    spapr->icp = xics_system_init(XICS_IRQS);
-    spapr->next_irq = XICS_IRQ_BASE;
-
     /* Set up EPOW events infrastructure */
     spapr_events_init(spapr);
 
diff --git a/hw/xics.c b/hw/xics.c
index b8887cd..f72dfae 100644
--- a/hw/xics.c
+++ b/hw/xics.c
@@ -510,42 +510,36 @@ static void xics_reset(void *opaque)
     }
 }
 
-struct icp_state *xics_system_init(int nr_irqs)
+void xics_cpu_setup(struct icp_state *icp, CPUPPCState *env)
 {
-    CPUPPCState *env;
-    int max_server_num;
-    struct icp_state *icp;
-    struct ics_state *ics;
+    struct icp_server_state *ss = &icp->ss[env->cpu_index];
 
-    max_server_num = -1;
-    for (env = first_cpu; env != NULL; env = env->next_cpu) {
-        if (env->cpu_index > max_server_num) {
-            max_server_num = env->cpu_index;
-        }
-    }
+    assert(env->cpu_index < icp->nr_servers);
 
-    icp = g_malloc0(sizeof(*icp));
-    icp->nr_servers = max_server_num + 1;
-    icp->ss = g_malloc0(icp->nr_servers*sizeof(struct icp_server_state));
+    switch (PPC_INPUT(env)) {
+    case PPC_FLAGS_INPUT_POWER7:
+        ss->output = env->irq_inputs[POWER7_INPUT_INT];
+        break;
 
-    for (env = first_cpu; env != NULL; env = env->next_cpu) {
-        struct icp_server_state *ss = &icp->ss[env->cpu_index];
+    case PPC_FLAGS_INPUT_970:
+        ss->output = env->irq_inputs[PPC970_INPUT_INT];
+        break;
 
-        switch (PPC_INPUT(env)) {
-        case PPC_FLAGS_INPUT_POWER7:
-            ss->output = env->irq_inputs[POWER7_INPUT_INT];
-            break;
+    default:
+        fprintf(stderr, "XICS interrupt controller does not support this CPU "
+                "bus model\n");
+        abort();
+    }
+}
 
-        case PPC_FLAGS_INPUT_970:
-            ss->output = env->irq_inputs[PPC970_INPUT_INT];
-            break;
+struct icp_state *xics_system_init(int nr_servers, int nr_irqs)
+{
+    struct icp_state *icp;
+    struct ics_state *ics;
 
-        default:
-            hw_error("XICS interrupt model does not support this CPU bus "
-                     "model\n");
-            exit(1);
-        }
-    }
+    icp = g_malloc0(sizeof(*icp));
+    icp->nr_servers = nr_servers;
+    icp->ss = g_malloc0(icp->nr_servers*sizeof(struct icp_server_state));
 
     ics = g_malloc0(sizeof(*ics));
     ics->nr_irqs = nr_irqs;
diff --git a/hw/xics.h b/hw/xics.h
index c3bf008..b43678a 100644
--- a/hw/xics.h
+++ b/hw/xics.h
@@ -35,6 +35,7 @@ struct icp_state;
 qemu_irq xics_get_qirq(struct icp_state *icp, int irq);
 void xics_set_irq_type(struct icp_state *icp, int irq, bool lsi);
 
-struct icp_state *xics_system_init(int nr_irqs);
+struct icp_state *xics_system_init(int nr_servers, int nr_irqs);
+void xics_cpu_setup(struct icp_state *icp, CPUPPCState *env);
 
 #endif /* __XICS_H__ */
-- 
1.7.10.4