Implement the PAPR (pSeries) virtualized interrupt controller (xics)

PAPR defines an interrupt control architecture which is logically divided
into ICS (Interrupt Control Presentation, each unit is responsible for
presenting interrupts to a particular "interrupt server", i.e. CPU) and
ICS (Interrupt Control Source, each unit responsible for one or more
hardware interrupts as numbered globally across the system).  All PAPR
virtual IO devices expect to deliver interrupts via this mechanism.  In
Linux, this interrupt controller system is handled by the "xics" driver.

On pSeries systems, access to the interrupt controller is virtualized via
hypercalls and RTAS methods.  However, the virtualized interface is very
similar to the underlying interrupt controller hardware, and similar PICs
exist un-virtualized in some other systems.

This patch implements both the ICP and ICS sides of the PAPR interrupt
controller.  For now, only the hypercall virtualized interface is provided,
however it would be relatively straightforward to graft an emulated
register interface onto the underlying interrupt logic if we want to add
a machine with a hardware ICS/ICP system in the future.

There are some limitations in this implementation: it is assumed for now
that only one instance of the ICS exists, although a full xics system can
have several, each responsible for a different group of hardware irqs.
ICP/ICS can handle both level-sensitve (LSI) and message signalled (MSI)
interrupt inputs.  For now, this implementation supports only MSI
interrupts, since that is used by PAPR virtual IO devices.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 27 insertions, 0 deletions

diff --git a/hw/spapr.c b/hw/spapr.c
index 6c64de82d..b5aefd72c 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -34,6 +34,7 @@
 
 #include "hw/spapr.h"
 #include "hw/spapr_vio.h"
+#include "hw/xics.h"
 
 #include <libfdt.h>
 
@@ -45,6 +46,7 @@
 #define TIMEBASE_FREQ           512000000ULL
 
 #define MAX_CPUS                32
+#define XICS_IRQS		1024
 
 sPAPREnvironment *spapr;
 
@@ -64,6 +66,7 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
     uint32_t end_prop = cpu_to_be32(initrd_base + initrd_size);
     uint32_t pft_size_prop[] = {0, cpu_to_be32(hash_shift)};
     char hypertas_prop[] = "hcall-pft\0hcall-term\0hcall-dabr";
+    uint32_t interrupt_server_ranges_prop[] = {0, cpu_to_be32(smp_cpus)};
     int i;
     char *modelname;
     int ret;
@@ -125,6 +128,7 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
 
     for (i = 0; i < smp_cpus; i++) {
         CPUState *env = envs[i];
+        uint32_t gserver_prop[] = {cpu_to_be32(i), 0}; /* HACK! */
         char *nodename;
         uint32_t segs[] = {cpu_to_be32(28), cpu_to_be32(40),
                            0xffffffff, 0xffffffff};
@@ -155,6 +159,9 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
                            pft_size_prop, sizeof(pft_size_prop))));
         _FDT((fdt_property_string(fdt, "status", "okay")));
         _FDT((fdt_property(fdt, "64-bit", NULL, 0)));
+        _FDT((fdt_property_cell(fdt, "ibm,ppc-interrupt-server#s", i)));
+        _FDT((fdt_property(fdt, "ibm,ppc-interrupt-gserver#s",
+                           gserver_prop, sizeof(gserver_prop))));
 
         if (envs[i]->mmu_model & POWERPC_MMU_1TSEG) {
             _FDT((fdt_property(fdt, "ibm,processor-segment-sizes",
@@ -176,6 +183,20 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
 
     _FDT((fdt_end_node(fdt)));
 
+    /* interrupt controller */
+    _FDT((fdt_begin_node(fdt, "interrupt-controller@0")));
+
+    _FDT((fdt_property_string(fdt, "device_type",
+                              "PowerPC-External-Interrupt-Presentation")));
+    _FDT((fdt_property_string(fdt, "compatible", "IBM,ppc-xicp")));
+    _FDT((fdt_property_cell(fdt, "reg", 0)));
+    _FDT((fdt_property(fdt, "interrupt-controller", NULL, 0)));
+    _FDT((fdt_property(fdt, "ibm,interrupt-server-ranges",
+                       interrupt_server_ranges_prop,
+                       sizeof(interrupt_server_ranges_prop))));
+
+    _FDT((fdt_end_node(fdt)));
+
     /* vdevice */
     _FDT((fdt_begin_node(fdt, "vdevice")));
 
@@ -183,6 +204,8 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
     _FDT((fdt_property_string(fdt, "compatible", "IBM,vdevice")));
     _FDT((fdt_property_cell(fdt, "#address-cells", 0x1)));
     _FDT((fdt_property_cell(fdt, "#size-cells", 0x0)));
+    _FDT((fdt_property_cell(fdt, "#interrupt-cells", 0x2)));
+    _FDT((fdt_property(fdt, "interrupt-controller", NULL, 0)));
 
     _FDT((fdt_end_node(fdt)));
 
@@ -296,6 +319,10 @@ static void ppc_spapr_init(ram_addr_t ram_size,
     }
     qemu_free(filename);
 
+    /* Set up Interrupt Controller */
+    spapr->icp = xics_system_init(smp_cpus, envs, XICS_IRQS);
+
+    /* Set up VIO bus */
     spapr->vio_bus = spapr_vio_bus_init();
 
     for (i = 0; i < MAX_SERIAL_PORTS; i++) {