[PATCH 15/17] ppc/pnv: convert pec->stacks[] into pec->phbs[]

[Daniel Henrique Barboza]

This patch changes the design of the PEC device to use PHB4s instead of
PecStacks. After all the recent changes, PHB4s now contain all the
information needed for their proper functioning, not relying on PecStack
in any capacity.

All changes are being made in a single patch to avoid renaming parts of
the PecState and leaving the code in a strange way. E.g. rename
PecClass->num_stacks to num_phbs, which would then read a
pnv_pec_num_stacks[] array. To avoid mixing the old and new design more
than necessary it's clearer to do these changes in a single step.

The name changes made are:

- in PnvPhb4PecState, rename PHB4_PEC_MAX_STACKS to PHB4_PEC_MAX_PHBS,
'num_stacks' to 'num_phbs' and convert "PnvPhb4PecStack
stacks[PHB4_PEC_MAX_STACKS]" to "PnvPHB4 *phbs[PHB4_PEC_MAX_PHBS]";

- in PnvPhb4PecClass, rename *num_stacks to *num_phbs;

- pnv_pec_num_stacks[] is renamed to pnv_pec_num_phbs[].

The logical changes:

- pnv_pec_default_phb_realize():
  * init the PnvPHB4 qdev and assign it to the corresponding
pec->phbs[phb_number];
  * do not use stack->phb anymore;

- pnv_pec_realize():
  * use the new default_phb_realize() to init/realize each PHB if
running with defaults;

- pnv_pec_instance_init(): removed since we're creating the PHBs during
pec_realize();

- pnv_phb4_get_stack():
  * renamed to pnv_phb4_get_pec() and returns a PnvPhb4PecState*;
  * assign the right pec->phbs[] pointer to the phb;
  * set 'phb_number' of the PHB given that the information is already
available;

- pnv_phb4_realize(): use 'phb->pec' instead of 'stack'.

This design change shouldn't caused any behavioral change in the runtime
of the machine.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/pci-host/pnv_phb4.c         | 31 +++++++--------
 hw/pci-host/pnv_phb4_pec.c     | 71 ++++++++++------------------------
 include/hw/pci-host/pnv_phb4.h | 10 ++---
 3 files changed, 40 insertions(+), 72 deletions(-)

diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
index 25b4248776..a9ec42ce2c 100644
--- a/hw/pci-host/pnv_phb4.c
+++ b/hw/pci-host/pnv_phb4.c
@@ -1360,7 +1360,7 @@ int pnv_phb4_pec_get_phb_id(PnvPhb4PecState *pec, int 
stack_index)
     int offset = 0;
 
     while (index--) {
-        offset += pecc->num_stacks[index];
+        offset += pecc->num_phbs[index];
     }
 
     return offset + stack_index;
@@ -1510,8 +1510,8 @@ static void pnv_phb4_instance_init(Object *obj)
     object_initialize_child(obj, "source", &phb->xsrc, TYPE_XIVE_SOURCE);
 }
 
-static PnvPhb4PecStack *pnv_phb4_get_stack(PnvChip *chip, PnvPHB4 *phb,
-                                           Error **errp)
+static PnvPhb4PecState *pnv_phb4_get_pec(PnvChip *chip, PnvPHB4 *phb,
+                                         Error **errp)
 {
     Pnv9Chip *chip9 = PNV9_CHIP(chip);
     int chip_id = phb->chip_id;
@@ -1520,14 +1520,19 @@ static PnvPhb4PecStack *pnv_phb4_get_stack(PnvChip 
*chip, PnvPHB4 *phb,
 
     for (i = 0; i < chip->num_pecs; i++) {
         /*
-         * For each PEC, check the amount of stacks it supports
-         * and see if the given phb4 index matches a stack.
+         * For each PEC, check the amount of phbs it supports
+         * and see if the given phb4 index matches an index.
          */
         PnvPhb4PecState *pec = &chip9->pecs[i];
 
-        for (j = 0; j < pec->num_stacks; j++) {
+        for (j = 0; j < pec->num_phbs; j++) {
             if (index == pnv_phb4_pec_get_phb_id(pec, j)) {
-                return &pec->stacks[j];
+                pec->phbs[j] = phb;
+
+                /* Set phb-number now since we already have it */
+                object_property_set_int(OBJECT(phb), "phb-number",
+                                               j, &error_abort);
+                return pec;
             }
         }
     }
@@ -1552,7 +1557,6 @@ static void pnv_phb4_realize(DeviceState *dev, Error 
**errp)
     if (!phb->pec) {
         PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
         PnvChip *chip = pnv_get_chip(pnv, phb->chip_id);
-        PnvPhb4PecStack *stack;
         PnvPhb4PecClass *pecc;
         BusState *s;
 
@@ -1561,23 +1565,16 @@ static void pnv_phb4_realize(DeviceState *dev, Error 
**errp)
             return;
         }
 
-        stack = pnv_phb4_get_stack(chip, phb, &local_err);
+        phb->pec = pnv_phb4_get_pec(chip, phb, &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
             return;
         }
 
-        /*
-         * All other phb properties but 'pec', 'version' and
-         * 'phb-number' are already set.
-         */
-        object_property_set_link(OBJECT(phb), "pec", OBJECT(stack->pec),
-                                 &error_abort);
+        /* All other phb properties are already set */
         pecc = PNV_PHB4_PEC_GET_CLASS(phb->pec);
         object_property_set_int(OBJECT(phb), "version", pecc->version,
                                 &error_fatal);
-        object_property_set_int(OBJECT(phb), "phb-number",
-                                stack->stack_no, &error_abort);
 
         /*
          * Reparent user created devices to the chip to build
diff --git a/hw/pci-host/pnv_phb4_pec.c b/hw/pci-host/pnv_phb4_pec.c
index 3339e0ea3d..61d7add25a 100644
--- a/hw/pci-host/pnv_phb4_pec.c
+++ b/hw/pci-host/pnv_phb4_pec.c
@@ -112,40 +112,29 @@ static const MemoryRegionOps pnv_pec_pci_xscom_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
-static void pnv_pec_default_phb_realize(PnvPhb4PecStack *stack,
+static void pnv_pec_default_phb_realize(PnvPhb4PecState *pec,
                                         int phb_number,
                                         Error **errp)
 {
-    PnvPhb4PecState *pec = stack->pec;
+    PnvPHB4 *phb = PNV_PHB4(qdev_new(TYPE_PNV_PHB4));
     PnvPhb4PecClass *pecc = PNV_PHB4_PEC_GET_CLASS(pec);
     int phb_id = pnv_phb4_pec_get_phb_id(pec, phb_number);
 
-    stack->phb = PNV_PHB4(qdev_new(TYPE_PNV_PHB4));
-
-    object_property_set_int(OBJECT(stack->phb), "phb-number", phb_number,
+    object_property_set_int(OBJECT(phb), "phb-number", phb_number,
                             &error_abort);
-    object_property_set_link(OBJECT(stack->phb), "pec", OBJECT(pec),
+    object_property_set_link(OBJECT(phb), "pec", OBJECT(pec),
                              &error_abort);
-    object_property_set_int(OBJECT(stack->phb), "chip-id", pec->chip_id,
+    object_property_set_int(OBJECT(phb), "chip-id", pec->chip_id,
                             &error_fatal);
-    object_property_set_int(OBJECT(stack->phb), "index", phb_id,
+    object_property_set_int(OBJECT(phb), "index", phb_id,
                             &error_fatal);
-    object_property_set_int(OBJECT(stack->phb), "version", pecc->version,
+    object_property_set_int(OBJECT(phb), "version", pecc->version,
                             &error_fatal);
 
-    if (!sysbus_realize(SYS_BUS_DEVICE(stack->phb), errp)) {
-        return;
-    }
-}
-
-static void pnv_pec_instance_init(Object *obj)
-{
-    PnvPhb4PecState *pec = PNV_PHB4_PEC(obj);
-    int i;
+    pec->phbs[phb_number] = phb;
 
-    for (i = 0; i < PHB4_PEC_MAX_STACKS; i++) {
-        object_initialize_child(obj, "stack[*]", &pec->stacks[i],
-                                TYPE_PNV_PHB4_PEC_STACK);
+    if (!sysbus_realize(SYS_BUS_DEVICE(phb), errp)) {
+        return;
     }
 }
 
@@ -161,30 +150,13 @@ static void pnv_pec_realize(DeviceState *dev, Error 
**errp)
         return;
     }
 
-    pec->num_stacks = pecc->num_stacks[pec->index];
-
-    /* Create stacks */
-    for (i = 0; i < pec->num_stacks; i++) {
-        PnvPhb4PecStack *stack = &pec->stacks[i];
-        Object *stk_obj = OBJECT(stack);
-
-        object_property_set_int(stk_obj, "stack-no", i, &error_abort);
-        object_property_set_link(stk_obj, "pec", OBJECT(pec), &error_abort);
+    pec->num_phbs = pecc->num_phbs[pec->index];
 
-        if (defaults_enabled()) {
-            pnv_pec_default_phb_realize(stack, i, errp);
+    /* Create PHBs if running with defaults */
+    if (defaults_enabled()) {
+        for (i = 0; i < pec->num_phbs; i++) {
+            pnv_pec_default_phb_realize(pec, i, errp);
         }
-
-        /*
-         * qdev gets angry if we don't realize 'stack' here, even
-         * if stk_realize() is now empty.
-         */
-        if (!qdev_realize(DEVICE(stk_obj), NULL, errp)) {
-            return;
-        }
-    }
-    for (; i < PHB4_PEC_MAX_STACKS; i++) {
-        object_unparent(OBJECT(&pec->stacks[i]));
     }
 
     /* Initialize the XSCOM regions for the PEC registers */
@@ -230,7 +202,7 @@ static int pnv_pec_dt_xscom(PnvXScomInterface *dev, void 
*fdt,
     _FDT((fdt_setprop(fdt, offset, "compatible", pecc->compat,
                       pecc->compat_size)));
 
-    for (i = 0; i < pec->num_stacks; i++) {
+    for (i = 0; i < pec->num_phbs; i++) {
         int phb_id = pnv_phb4_pec_get_phb_id(pec, i);
         int stk_offset;
 
@@ -266,11 +238,11 @@ static uint32_t pnv_pec_xscom_nest_base(PnvPhb4PecState 
*pec)
 }
 
 /*
- * PEC0 -> 1 stack
- * PEC1 -> 2 stacks
- * PEC2 -> 3 stacks
+ * PEC0 -> 1 phb
+ * PEC1 -> 2 phb
+ * PEC2 -> 3 phbs
  */
-static const uint32_t pnv_pec_num_stacks[] = { 1, 2, 3 };
+static const uint32_t pnv_pec_num_phbs[] = { 1, 2, 3 };
 
 static void pnv_pec_class_init(ObjectClass *klass, void *data)
 {
@@ -295,14 +267,13 @@ static void pnv_pec_class_init(ObjectClass *klass, void 
*data)
     pecc->stk_compat = stk_compat;
     pecc->stk_compat_size = sizeof(stk_compat);
     pecc->version = PNV_PHB4_VERSION;
-    pecc->num_stacks = pnv_pec_num_stacks;
+    pecc->num_phbs = pnv_pec_num_phbs;
 }
 
 static const TypeInfo pnv_pec_type_info = {
     .name          = TYPE_PNV_PHB4_PEC,
     .parent        = TYPE_DEVICE,
     .instance_size = sizeof(PnvPhb4PecState),
-    .instance_init = pnv_pec_instance_init,
     .class_init    = pnv_pec_class_init,
     .class_size    = sizeof(PnvPhb4PecClass),
     .interfaces    = (InterfaceInfo[]) {
diff --git a/include/hw/pci-host/pnv_phb4.h b/include/hw/pci-host/pnv_phb4.h
index 90eb4575f8..170de2e752 100644
--- a/include/hw/pci-host/pnv_phb4.h
+++ b/include/hw/pci-host/pnv_phb4.h
@@ -206,10 +206,10 @@ struct PnvPhb4PecState {
     uint64_t pci_regs[PHB4_PEC_PCI_REGS_COUNT];
     MemoryRegion pci_regs_mr;
 
-    /* Stacks */
-    #define PHB4_PEC_MAX_STACKS     3
-    uint32_t num_stacks;
-    PnvPhb4PecStack stacks[PHB4_PEC_MAX_STACKS];
+    /* PHBs */
+    #define PHB4_PEC_MAX_PHBS     3
+    uint32_t num_phbs;
+    PnvPHB4 *phbs[PHB4_PEC_MAX_PHBS];
 
     PnvChip *chip;
 };
@@ -227,7 +227,7 @@ struct PnvPhb4PecClass {
     const char *stk_compat;
     int stk_compat_size;
     uint64_t version;
-    const uint32_t *num_stacks;
+    const uint32_t *num_phbs;
 };
 
 #endif /* PCI_HOST_PNV_PHB4_H */
-- 
2.33.1