ppc/pnv: Add QME region for P10

The Quad Management Engine (QME) manages power related settings for its
quad. The xscom region is separate from the quad xscoms, therefore a new
region is added. The xscoms in a QME select a given core by selecting
the forth nibble.

Implement dummy reads for the stop state history (SSH) and special
wakeup (SPWU) registers. This quietens some sxcom errors when skiboot
boots on p10.

Power9 does not have a QME.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Message-ID: <20230707071213.9924-1-joel@jms.id.au>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

hw/ppc/pnv.c

@@ -1685,6 +1685,9 @@ static void pnv_chip_power10_quad_realize(Pnv10Chip *chip10, Error **errp)
 
         pnv_xscom_add_subregion(chip, PNV10_XSCOM_EQ_BASE(eq->quad_id),
                                 &eq->xscom_regs);
+
+        pnv_xscom_add_subregion(chip, PNV10_XSCOM_QME_BASE(eq->quad_id),
+                                &eq->xscom_qme_regs);
     }
 }
 

hw/ppc/pnv_core.c

@@ -496,7 +496,67 @@ static const MemoryRegionOps pnv_quad_power10_xscom_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
-static void pnv_quad_realize(DeviceState *dev, Error **errp)
+#define P10_QME_SPWU_HYP 0x83c
+#define P10_QME_SSH_HYP  0x82c
+
+static uint64_t pnv_qme_power10_xscom_read(void *opaque, hwaddr addr,
+                                            unsigned int width)
+{
+    uint32_t offset = addr >> 3;
+    uint64_t val = -1;
+
+    /*
+     * Forth nibble selects the core within a quad, mask it to process read
+     * for any core.
+     */
+    switch (offset & ~0xf000) {
+    case P10_QME_SPWU_HYP:
+    case P10_QME_SSH_HYP:
+        return 0;
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: unimp read 0x%08x\n", __func__,
+                      offset);
+    }
+
+    return val;
+}
+
+static void pnv_qme_power10_xscom_write(void *opaque, hwaddr addr,
+                                         uint64_t val, unsigned int width)
+{
+    uint32_t offset = addr >> 3;
+
+    switch (offset) {
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: unimp write 0x%08x\n", __func__,
+                      offset);
+    }
+}
+
+static const MemoryRegionOps pnv_qme_power10_xscom_ops = {
+    .read = pnv_qme_power10_xscom_read,
+    .write = pnv_qme_power10_xscom_write,
+    .valid.min_access_size = 8,
+    .valid.max_access_size = 8,
+    .impl.min_access_size = 8,
+    .impl.max_access_size = 8,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+static void pnv_quad_power9_realize(DeviceState *dev, Error **errp)
+{
+    PnvQuad *eq = PNV_QUAD(dev);
+    PnvQuadClass *pqc = PNV_QUAD_GET_CLASS(eq);
+    char name[32];
+
+    snprintf(name, sizeof(name), "xscom-quad.%d", eq->quad_id);
+    pnv_xscom_region_init(&eq->xscom_regs, OBJECT(dev),
+                          pqc->xscom_ops,
+                          eq, name,
+                          pqc->xscom_size);
+}
+
+static void pnv_quad_power10_realize(DeviceState *dev, Error **errp)
 {
     PnvQuad *eq = PNV_QUAD(dev);
     PnvQuadClass *pqc = PNV_QUAD_GET_CLASS(eq);
@@ -507,6 +567,12 @@ static void pnv_quad_realize(DeviceState *dev, Error **errp)
                           pqc->xscom_ops,
                           eq, name,
                           pqc->xscom_size);
+
+    snprintf(name, sizeof(name), "xscom-qme.%d", eq->quad_id);
+    pnv_xscom_region_init(&eq->xscom_qme_regs, OBJECT(dev),
+                          pqc->xscom_qme_ops,
+                          eq, name,
+                          pqc->xscom_qme_size);
 }
 
 static Property pnv_quad_properties[] = {
@@ -517,6 +583,9 @@ static Property pnv_quad_properties[] = {
 static void pnv_quad_power9_class_init(ObjectClass *oc, void *data)
 {
     PnvQuadClass *pqc = PNV_QUAD_CLASS(oc);
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = pnv_quad_power9_realize;
 
     pqc->xscom_ops = &pnv_quad_power9_xscom_ops;
     pqc->xscom_size = PNV9_XSCOM_EQ_SIZE;
@@ -525,16 +594,21 @@ static void pnv_quad_power9_class_init(ObjectClass *oc, void *data)
 static void pnv_quad_power10_class_init(ObjectClass *oc, void *data)
 {
     PnvQuadClass *pqc = PNV_QUAD_CLASS(oc);
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = pnv_quad_power10_realize;
 
     pqc->xscom_ops = &pnv_quad_power10_xscom_ops;
     pqc->xscom_size = PNV10_XSCOM_EQ_SIZE;
+
+    pqc->xscom_qme_ops = &pnv_qme_power10_xscom_ops;
+    pqc->xscom_qme_size = PNV10_XSCOM_QME_SIZE;
 }
 
 static void pnv_quad_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
 
-    dc->realize = pnv_quad_realize;
     device_class_set_props(dc, pnv_quad_properties);
     dc->user_creatable = false;
 }

include/hw/ppc/pnv_core.h

@@ -66,6 +66,9 @@ struct PnvQuadClass {
 
     const MemoryRegionOps *xscom_ops;
     uint64_t xscom_size;
+
+    const MemoryRegionOps *xscom_qme_ops;
+    uint64_t xscom_qme_size;
 };
 
 #define TYPE_PNV_QUAD "powernv-cpu-quad"
@@ -80,5 +83,6 @@ struct PnvQuad {
 
     uint32_t quad_id;
     MemoryRegion xscom_regs;
+    MemoryRegion xscom_qme_regs;
 };
 #endif /* PPC_PNV_CORE_H */

include/hw/ppc/pnv_xscom.h

@@ -127,6 +127,17 @@ struct PnvXScomInterfaceClass {
 #define PNV10_XSCOM_EC(proc)                    \
     ((0x2 << 16) | ((1 << (3 - (proc))) << 12))
 
+#define PNV10_XSCOM_QME(chiplet) \
+        (PNV10_XSCOM_EQ(chiplet) | (0xE << 16))
+
+/*
+ * Make the region larger by 0x1000 (instead of starting at an offset) so the
+ * modelled addresses start from 0
+ */
+#define PNV10_XSCOM_QME_BASE(core)     \
+    ((uint64_t) PNV10_XSCOM_QME(PNV10_XSCOM_EQ_CHIPLET(core)))
+#define PNV10_XSCOM_QME_SIZE        (0x8000 + 0x1000)
+
 #define PNV10_XSCOM_EQ_BASE(core)     \
     ((uint64_t) PNV10_XSCOM_EQ(PNV10_XSCOM_EQ_CHIPLET(core)))
 #define PNV10_XSCOM_EQ_SIZE        0x20000