[Qemu-devel] [PATCH 01/19] ppc/xive: hardwire the Physical CAM line of the thread context

[Cédric Le Goater]

By default on P9, the HW CAM line (23bits) is hardwired to :

      0x000||0b1||4Bit chip number||7Bit Thread number.

When the block group mode is enabled at the controller level (PowerNV),
the CAM line is changed for CAM compares to :

      4Bit chip number||0x001||7Bit Thread number

This will require changes in xive_presenter_tctx_match() possibly.
This is a lowlevel functionality of the HW controller and it is not
strictly needed. Leave it for later.

Signed-off-by: Cédric Le Goater <address@hidden>
---
 include/hw/ppc/xive.h |  1 +
 hw/intc/xive.c        | 53 ++++++++++++++++++++++++++++++++++++++++---
 hw/ppc/pnv_core.c     | 16 ++++++++-----
 3 files changed, 61 insertions(+), 9 deletions(-)

diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
index ec3bb2aae45a..04d54e8315f7 100644
--- a/include/hw/ppc/xive.h
+++ b/include/hw/ppc/xive.h
@@ -319,6 +319,7 @@ typedef struct XiveTCTX {
     qemu_irq    output;
 
     uint8_t     regs[XIVE_TM_RING_COUNT * XIVE_TM_RING_SIZE];
+    uint32_t    hw_cam;
 } XiveTCTX;
 
 /*
diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 2e9b8efd4342..f5642f2338de 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -469,6 +469,12 @@ static void xive_tctx_realize(DeviceState *dev, Error 
**errp)
     Object *obj;
     Error *local_err = NULL;
 
+    if (!tctx->hw_cam) {
+        error_setg(errp, "XIVE: HW CAM is not set for CPU %d",
+                   tctx->cs->cpu_index);
+        return;
+    }
+
     obj = object_property_get_link(OBJECT(dev), "cpu", &local_err);
     if (!obj) {
         error_propagate(errp, local_err);
@@ -509,11 +515,17 @@ static const VMStateDescription vmstate_xive_tctx = {
     },
 };
 
+static Property  xive_tctx_properties[] = {
+    DEFINE_PROP_UINT32("hw-cam", XiveTCTX, hw_cam, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void xive_tctx_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->desc = "XIVE Interrupt Thread Context";
+    dc->props = xive_tctx_properties;
     dc->realize = xive_tctx_realize;
     dc->unrealize = xive_tctx_unrealize;
     dc->vmsd = &vmstate_xive_tctx;
@@ -526,8 +538,21 @@ static const TypeInfo xive_tctx_info = {
     .class_init    = xive_tctx_class_init,
 };
 
+/*
+ * The HW CAM line (23bits) is hardwired to :
+ *
+ *   0x000||0b1||4Bit chip number||7Bit Thread number.
+ */
+static uint32_t hw_cam_line(uint8_t chip_id, uint8_t tid)
+{
+    return 1 << 11 | (chip_id & 0xf) << 7 | (tid & 0x7f);
+}
+
 Object *xive_tctx_create(Object *cpu, XiveRouter *xrtr, Error **errp)
 {
+    CPUPPCState *env = &POWERPC_CPU(cpu)->env;
+    uint32_t pir = env->spr_cb[SPR_PIR].default_value;
+    uint32_t hw_cam = hw_cam_line((pir >> 8) & 0xf, pir & 0x7f);
     Error *local_err = NULL;
     Object *obj;
 
@@ -535,6 +560,10 @@ Object *xive_tctx_create(Object *cpu, XiveRouter *xrtr, 
Error **errp)
     object_property_add_child(cpu, TYPE_XIVE_TCTX, obj, &error_abort);
     object_unref(obj);
     object_property_add_const_link(obj, "cpu", cpu, &error_abort);
+    object_property_set_int(obj, hw_cam, "hw-cam", &local_err);
+    if (local_err) {
+        goto error;
+    }
     object_property_set_bool(obj, true, "realized", &local_err);
     if (local_err) {
         goto error;
@@ -1112,14 +1141,28 @@ XiveTCTX *xive_router_get_tctx(XiveRouter *xrtr, 
CPUState *cs)
     return xrc->get_tctx(xrtr, cs);
 }
 
+/*
+ * When the block grouping is enabled, the CAM line is changed to :
+ *
+ *   4Bit chip number||0x001||7Bit Thread number.
+ */
+static bool xive_presenter_tctx_match_hw(XiveRouter *xrtr, XiveTCTX *tctx,
+                                         uint8_t nvt_blk, uint32_t nvt_idx)
+{
+    /* TODO: block group support */
+    return tctx->hw_cam == hw_cam_line(nvt_blk, nvt_idx);
+}
+
 /*
  * The thread context register words are in big-endian format.
  */
-static int xive_presenter_tctx_match(XiveTCTX *tctx, uint8_t format,
+static int xive_presenter_tctx_match(XiveRouter *xrtr,
+                                     XiveTCTX *tctx, uint8_t format,
                                      uint8_t nvt_blk, uint32_t nvt_idx,
                                      bool cam_ignore, uint32_t logic_serv)
 {
     uint32_t cam = xive_nvt_cam_line(nvt_blk, nvt_idx);
+    uint32_t qw3w2 = xive_tctx_word2(&tctx->regs[TM_QW3_HV_PHYS]);
     uint32_t qw2w2 = xive_tctx_word2(&tctx->regs[TM_QW2_HV_POOL]);
     uint32_t qw1w2 = xive_tctx_word2(&tctx->regs[TM_QW1_OS]);
     uint32_t qw0w2 = xive_tctx_word2(&tctx->regs[TM_QW0_USER]);
@@ -1142,7 +1185,11 @@ static int xive_presenter_tctx_match(XiveTCTX *tctx, 
uint8_t format,
 
         /* F=0 & i=0: Specific NVT notification */
 
-        /* TODO (PowerNV) : PHYS ring */
+        /* PHYS ring */
+        if ((be32_to_cpu(qw3w2) & TM_QW3W2_VT) &&
+            xive_presenter_tctx_match_hw(xrtr, tctx, nvt_blk, nvt_idx)) {
+            return TM_QW3_HV_PHYS;
+        }
 
         /* HV POOL ring */
         if ((be32_to_cpu(qw2w2) & TM_QW2W2_VP) &&
@@ -1199,7 +1246,7 @@ static bool xive_presenter_match(XiveRouter *xrtr, 
uint8_t format,
          * Check the thread context CAM lines and record matches. We
          * will handle CPU exception delivery later
          */
-        ring = xive_presenter_tctx_match(tctx, format, nvt_blk, nvt_idx,
+        ring = xive_presenter_tctx_match(xrtr, tctx, format, nvt_blk, nvt_idx,
                                          cam_ignore, logic_serv);
         /*
          * Save the context and follow on to catch duplicates, that we
diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c
index 7c806da720c6..f035522b4ec9 100644
--- a/hw/ppc/pnv_core.c
+++ b/hw/ppc/pnv_core.c
@@ -114,12 +114,6 @@ static void pnv_realize_vcpu(PowerPCCPU *cpu, PnvChip 
*chip, Error **errp)
         return;
     }
 
-    pcc->intc_create(chip, cpu, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        return;
-    }
-
     core_pir = object_property_get_uint(OBJECT(cpu), "core-pir", &error_abort);
 
     /*
@@ -129,6 +123,16 @@ static void pnv_realize_vcpu(PowerPCCPU *cpu, PnvChip 
*chip, Error **errp)
      */
     pir->default_value = core_pir + thread_index;
 
+    /*
+     * On P9, the interrupt presenter needs to hardwire the PIR value
+     * in the thread interrupt context of the CPU.
+     */
+    pcc->intc_create(chip, cpu, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
     /* Set time-base frequency to 512 MHz */
     cpu_ppc_tb_init(env, PNV_TIMEBASE_FREQ);
 
-- 
2.20.1