[Qemu-ppc] [PATCH for-2.10 4/8] ppc/pnv: add memory regions for the ICP registers

[Cédric Le Goater]

This provides to a PowerNV chip (POWER8) access to the Interrupt
Management area, which contains the registers of the Interrupt Control
Presenters of each thread. These are used to accept, return, forward
interrupts in the system.

This area is modeled with a per-chip container memory region holding
all the ICP registers. Each thread of a chip is then associated with
its ICP registers using a memory subregion indexed by its PIR number
in the overall region.

Signed-off-by: Cédric Le Goater <address@hidden>
---
 hw/ppc/pnv.c              |  20 +++++++
 hw/ppc/pnv_core.c         | 146 ++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/pnv.h      |  20 +++++++
 include/hw/ppc/pnv_core.h |   1 +
 include/hw/ppc/xics.h     |   3 +
 5 files changed, 190 insertions(+)

diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 461d3535e99c..7b13b08deadf 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -658,6 +658,16 @@ static void pnv_chip_init(Object *obj)
     object_property_add_child(obj, "lpc", OBJECT(&chip->lpc), NULL);
 }
 
+static void pnv_chip_icp_realize(PnvChip *chip, Error **errp)
+{
+    char *name;
+
+    name = g_strdup_printf("icp-%x", chip->chip_id);
+    memory_region_init(&chip->icp_mmio, OBJECT(chip), name, PNV_ICP_SIZE);
+    sysbus_init_mmio(SYS_BUS_DEVICE(chip), &chip->icp_mmio);
+    g_free(name);
+}
+
 static void pnv_chip_realize(DeviceState *dev, Error **errp)
 {
     PnvChip *chip = PNV_CHIP(dev);
@@ -680,6 +690,14 @@ static void pnv_chip_realize(DeviceState *dev, Error 
**errp)
     }
     sysbus_mmio_map(SYS_BUS_DEVICE(chip), 0, PNV_XSCOM_BASE(chip));
 
+    /* Interrupt Management Area. This is the memory region holding
+     * all the Interrupt Control Presenter (ICP) registers */
+    pnv_chip_icp_realize(chip, &error);
+    if (error) {
+        error_propagate(errp, error);
+        return;
+    }
+
     /* Cores */
     pnv_chip_core_sanitize(chip, &error);
     if (error) {
@@ -709,6 +727,8 @@ static void pnv_chip_realize(DeviceState *dev, Error **errp)
         object_property_set_int(OBJECT(pnv_core),
                                 pcc->core_pir(chip, core_hwid),
                                 "pir", &error_fatal);
+        object_property_add_const_link(OBJECT(pnv_core), "xics",
+                                       qdev_get_machine(), &error_fatal);
         object_property_set_bool(OBJECT(pnv_core), true, "realized",
                                  &error_fatal);
         object_unref(OBJECT(pnv_core));
diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c
index d79d530b4881..8633afbff795 100644
--- a/hw/ppc/pnv_core.c
+++ b/hw/ppc/pnv_core.c
@@ -26,6 +26,128 @@
 #include "hw/ppc/pnv_core.h"
 #include "hw/ppc/pnv_xscom.h"
 
+static uint64_t pnv_core_icp_read(void *opaque, hwaddr addr, unsigned width)
+{
+    ICPState *icp = opaque;
+    bool byte0 = (width == 1 && (addr & 0x3) == 0);
+    uint64_t val = 0xffffffff;
+
+    switch (addr & 0xffc) {
+    case 0: /* poll */
+        val = icp_ipoll(icp, NULL);
+        if (byte0) {
+            val >>= 24;
+        } else if (width != 4) {
+            goto bad_access;
+        }
+        break;
+    case 4: /* xirr */
+        if (byte0) {
+            val = icp_ipoll(icp, NULL) >> 24;
+        } else if (width == 4) {
+            val = icp_accept(icp);
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 12:
+        if (byte0) {
+            val = icp->mfrr;
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 16:
+        if (width == 4) {
+            val = icp->links[0];
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 20:
+        if (width == 4) {
+            val = icp->links[1];
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 24:
+        if (width == 4) {
+            val = icp->links[2];
+        } else {
+            goto bad_access;
+        }
+        break;
+    default:
+bad_access:
+        qemu_log_mask(LOG_GUEST_ERROR, "XICS: Bad ICP access 0x%"
+                      HWADDR_PRIx"/%d\n", addr, width);
+    }
+
+    return val;
+}
+
+static void pnv_core_icp_write(void *opaque, hwaddr addr, uint64_t val,
+                              unsigned width)
+{
+    ICPState *icp = opaque;
+    bool byte0 = (width == 1 && (addr & 0x3) == 0);
+
+    switch (addr & 0xffc) {
+    case 4: /* xirr */
+        if (byte0) {
+            icp_set_cppr(icp, val);
+        } else if (width == 4) {
+            icp_eoi(icp, val);
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 12:
+        if (byte0) {
+            icp_set_mfrr(icp, val);
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 16:
+        if (width == 4) {
+            icp->links[0] = val;
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 20:
+        if (width == 4) {
+            icp->links[1] = val;
+        } else {
+            goto bad_access;
+        }
+        break;
+    case 24:
+        if (width == 4) {
+            icp->links[2] = val;
+        } else {
+            goto bad_access;
+        }
+        break;
+    default:
+bad_access:
+        qemu_log_mask(LOG_GUEST_ERROR, "XICS: Bad ICP access 0x%"
+                      HWADDR_PRIx"/%d\n", addr, width);
+    }
+}
+
+static const MemoryRegionOps pnv_core_icp_ops = {
+    .read = pnv_core_icp_read,
+    .write = pnv_core_icp_write,
+    .valid.min_access_size = 1,
+    .valid.max_access_size = 4,
+    .impl.min_access_size = 1,
+    .impl.max_access_size = 4,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
 static void powernv_cpu_reset(void *opaque)
 {
     PowerPCCPU *cpu = opaque;
@@ -129,6 +251,14 @@ static void pnv_core_realize_child(Object *child, Error 
**errp)
     }
 }
 
+static ICPState *xics_get_icp_per_pir(XICSFabric *xi, int pir)
+{
+    int index = xics_get_cpu_index_by_pir(pir);
+    assert(index != -1);
+
+    return xics_icp_get(xi, index);
+}
+
 static void pnv_core_realize(DeviceState *dev, Error **errp)
 {
     PnvCore *pc = PNV_CORE(OBJECT(dev));
@@ -140,6 +270,14 @@ static void pnv_core_realize(DeviceState *dev, Error 
**errp)
     void *obj;
     int i, j;
     char name[32];
+    Object *xi;
+
+    xi = object_property_get_link(OBJECT(dev), "xics", &local_err);
+    if (!xi) {
+        error_setg(errp, "%s: required link 'xics' not found: %s",
+                   __func__, error_get_pretty(local_err));
+        return;
+    }
 
     pc->threads = g_malloc0(size * cc->nr_threads);
     for (i = 0; i < cc->nr_threads; i++) {
@@ -169,6 +307,14 @@ static void pnv_core_realize(DeviceState *dev, Error 
**errp)
     snprintf(name, sizeof(name), "xscom-core.%d", cc->core_id);
     pnv_xscom_region_init(&pc->xscom_regs, OBJECT(dev), &pnv_core_xscom_ops,
                           pc, name, PNV_XSCOM_EX_CORE_SIZE);
+
+    pc->icp_mmios = g_new0(MemoryRegion, cc->nr_threads);
+    for (i = 0; i < cc->nr_threads; i++) {
+        ICPState *icp = xics_get_icp_per_pir(XICS_FABRIC(xi), pc->pir + i);
+        snprintf(name, sizeof(name), "icp-core.%d", cc->core_id);
+        memory_region_init_io(&pc->icp_mmios[i], OBJECT(dev),
+                              &pnv_core_icp_ops, icp, name, 0x1000);
+    }
     return;
 
 err:
diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
index 6a0b004cea93..f11215ea31f2 100644
--- a/include/hw/ppc/pnv.h
+++ b/include/hw/ppc/pnv.h
@@ -55,6 +55,7 @@ typedef struct PnvChip {
     MemoryRegion xscom_mmio;
     MemoryRegion xscom;
     AddressSpace xscom_as;
+    MemoryRegion icp_mmio;
 
     PnvLpcController lpc;
 } PnvChip;
@@ -130,4 +131,23 @@ typedef struct PnvMachineState {
 #define PNV_XSCOM_BASE(chip)                                            \
     (chip->xscom_base + ((uint64_t)(chip)->chip_id) * PNV_XSCOM_SIZE)
 
+/*
+ * XSCOM 0x20109CA defines the ICP BAR:
+ *
+ * 0:29   : bits 14 to 43 of address to define 1 MB region.
+ * 30     : 1 to enable ICP to receive loads/stores against its BAR region
+ * 31:63  : Constant 0
+ *
+ * Usually defined as :
+ *
+ *      0xffffe00200000000 -> 0x0003ffff80000000
+ *      0xffffe00600000000 -> 0x0003ffff80100000
+ *      0xffffe02200000000 -> 0x0003ffff80800000
+ *      0xffffe02600000000 -> 0x0003ffff80900000
+ *
+ * TODO: make a macro using the chip hw id
+ */
+#define PNV_ICP_BASE(chip)   0x0003ffff80000000ull
+#define PNV_ICP_SIZE         0x0000000000100000ull
+
 #endif /* _PPC_PNV_H */
diff --git a/include/hw/ppc/pnv_core.h b/include/hw/ppc/pnv_core.h
index 2955a41c901f..f2fad8f6361b 100644
--- a/include/hw/ppc/pnv_core.h
+++ b/include/hw/ppc/pnv_core.h
@@ -38,6 +38,7 @@ typedef struct PnvCore {
     uint32_t pir;
 
     MemoryRegion xscom_regs;
+    MemoryRegion *icp_mmios;
 } PnvCore;
 
 typedef struct PnvCoreClass {
diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
index c2032cac55f6..a3dcdf93bbe3 100644
--- a/include/hw/ppc/xics.h
+++ b/include/hw/ppc/xics.h
@@ -78,6 +78,9 @@ struct ICPState {
     bool cap_irq_xics_enabled;
 
     XICSFabric *xics;
+
+    /* for the PowerNV ICP registers (not used by Linux). */
+    uint32_t links[3];
 };
 
 #define TYPE_ICS_BASE "ics-base"
-- 
2.7.4