[Qemu-devel] [PATCH 13/25] pci: make pci configuration transaction more accurate.

[Isaku Yamahata]

This patch sorts out/enhances pci code to track pci bus topology
accurately.
- Track host bus bridge with pci domain number. Although the
  current qemu support only pci domian 0 yet.
- Track pci bridge parent-child relationship.
When looking down from pci host bus for pci sub bus, be aware of
secondary bus/subordinate bus.
Thus pci configuration transaction is more accurately emulated.

This patch adds new member to PCIBus to track pci bus topology.
Since qdev already tracks down bus relationship, those new member
wouldn't be necessary.
However it would be addressed later because not all the pci device
isn't converted to qdev yet.

Signed-off-by: Isaku Yamahata <address@hidden>
---
 hw/apb_pci.c     |    4 +-
 hw/pci-hotplug.c |    6 +-
 hw/pci.c         |  121 ++++++++++++++++++++++++++++++++++++++++--------------
 hw/pci.h         |   11 ++++-
 4 files changed, 103 insertions(+), 39 deletions(-)

diff --git a/hw/apb_pci.c b/hw/apb_pci.c
index eb77042..599e354 100644
--- a/hw/apb_pci.c
+++ b/hw/apb_pci.c
@@ -253,10 +253,10 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
     pci_create_simple(d->host_state.bus, 0, "pbm");
     /* APB secondary busses */
     *bus2 = pci_bridge_init(d->host_state.bus, 8, PCI_VENDOR_ID_SUN,
-                            PCI_DEVICE_ID_SUN_SIMBA, pci_apb_map_irq,
+                            PCI_DEVICE_ID_SUN_SIMBA, 1, 1, pci_apb_map_irq,
                             "Advanced PCI Bus secondary bridge 1");
     *bus3 = pci_bridge_init(d->host_state.bus, 9, PCI_VENDOR_ID_SUN,
-                            PCI_DEVICE_ID_SUN_SIMBA, pci_apb_map_irq,
+                            PCI_DEVICE_ID_SUN_SIMBA, 2, 2, pci_apb_map_irq,
                             "Advanced PCI Bus secondary bridge 2");
 
     return d->host_state.bus;
diff --git a/hw/pci-hotplug.c b/hw/pci-hotplug.c
index f3dc421..890ecc3 100644
--- a/hw/pci-hotplug.c
+++ b/hw/pci-hotplug.c
@@ -65,7 +65,7 @@ void drive_hot_add(Monitor *mon, const QDict *qdict)
         return;
     }
 
-    dev = pci_find_device(pci_bus, slot, 0);
+    dev = pci_find_device(pci_find_host_bus(0), pci_bus, slot, 0);
     if (!dev) {
         monitor_printf(mon, "no pci device with address %s\n", pci_addr);
         return;
@@ -201,7 +201,7 @@ void pci_device_hot_remove(Monitor *mon, const char 
*pci_addr)
         return;
     }
 
-    d = pci_find_device(bus, slot, 0);
+    d = pci_find_device(pci_find_host_bus(0), bus, slot, 0);
     if (!d) {
         monitor_printf(mon, "slot %d empty\n", slot);
         return;
@@ -228,7 +228,7 @@ static int pci_match_fn(void *dev_private, void *arg)
  */
 void pci_device_hot_remove_success(int pcibus, int slot)
 {
-    PCIDevice *d = pci_find_device(pcibus, slot, 0);
+    PCIDevice *d = pci_find_device(pci_find_host_bus(0), pcibus, slot, 0);
     int class_code;
 
     if (!d) {
diff --git a/hw/pci.c b/hw/pci.c
index 75af2cd..223d36a 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -34,9 +34,12 @@
 # define PCI_DPRINTF(format, ...)       do { } while (0)
 #endif
 
+#define PCI_BUS_NUM_MAX 255
 struct PCIBus {
     BusState qbus;
     int bus_num;
+    int sub_bus;
+
     int devfn_min;
     pci_set_irq_fn set_irq;
     pci_map_irq_fn map_irq;
@@ -44,7 +47,10 @@ struct PCIBus {
     void *irq_opaque;
     PCIDevice *devices[256];
     PCIDevice *parent_dev;
-    PCIBus *next;
+
+    QLIST_HEAD(, PCIBus) child; /* this will be replaced by qdev later */
+    QLIST_ENTRY(PCIBus) sibling;/* this will be replaced by qdev later */
+
     /* The bus IRQ state is the logical OR of the connected devices.
        Keep a count of the number of devices with raised IRQs.  */
     int nirq;
@@ -69,7 +75,13 @@ static void pci_set_irq(void *opaque, int irq_num, int 
level);
 target_phys_addr_t pci_mem_base;
 static uint16_t pci_default_sub_vendor_id = PCI_SUBVENDOR_ID_REDHAT_QUMRANET;
 static uint16_t pci_default_sub_device_id = PCI_SUBDEVICE_ID_QEMU;
-static PCIBus *first_bus;
+
+struct PCIHostBus {
+    int domain;
+    struct PCIBus *bus;
+    QLIST_ENTRY(PCIHostBus) next;
+};
+static QLIST_HEAD(, PCIHostBus) host_buses;
 
 static const VMStateDescription vmstate_pcibus = {
     .name = "PCIBUS",
@@ -98,6 +110,28 @@ static void pci_bus_reset(void *opaque)
     }
 }
 
+static void pci_host_bus_register(int domain, PCIBus *bus)
+{
+    struct PCIHostBus *host;
+    host = qemu_mallocz(sizeof(*host));
+    host->domain = domain;
+    host->bus = bus;
+    QLIST_INSERT_HEAD(&host_buses, host, next);
+}
+
+PCIBus *pci_find_host_bus(int domain)
+{
+    struct PCIHostBus *host;
+
+    QLIST_FOREACH(host, &host_buses, next) {
+        if (host->domain == domain) {
+            return host->bus;
+        }
+    }
+
+    return NULL;
+}
+
 PCIBus *pci_register_bus(DeviceState *parent, const char *name,
                          pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
                          void *irq_opaque, int devfn_min, int nirq)
@@ -112,14 +146,20 @@ PCIBus *pci_register_bus(DeviceState *parent, const char 
*name,
     bus->devfn_min = devfn_min;
     bus->nirq = nirq;
     bus->irq_count = qemu_mallocz(nirq * sizeof(bus->irq_count[0]));
-    bus->next = first_bus;
-    first_bus = bus;
+
+    /* host bridge */
+    bus->bus_num = 0;
+    bus->sub_bus = PCI_BUS_NUM_MAX;
+    QLIST_INIT(&bus->child);
+    pci_host_bus_register(0, bus); /* for now only pci domain 0 is supported */
+
     vmstate_register(nbus++, &vmstate_pcibus, bus);
     qemu_register_reset(pci_bus_reset, bus);
     return bus;
 }
 
-static PCIBus *pci_register_secondary_bus(PCIDevice *dev,
+static PCIBus *pci_register_secondary_bus(PCIBus *parent,
+                                          PCIDevice *dev,
                                           pci_map_irq_fn map_irq,
                                           const char *name)
 {
@@ -128,8 +168,11 @@ static PCIBus *pci_register_secondary_bus(PCIDevice *dev,
     bus = FROM_QBUS(PCIBus, qbus_create(&pci_bus_info, &dev->qdev, name));
     bus->map_irq = map_irq;
     bus->parent_dev = dev;
-    bus->next = dev->bus->next;
-    dev->bus->next = bus;
+
+    bus->bus_num = dev->config[PCI_SECONDARY_BUS];
+    bus->sub_bus = dev->config[PCI_SUBORDINATE_BUS];
+    QLIST_INIT(&bus->child);
+    QLIST_INSERT_HEAD(&parent->child, bus, sibling);
     return bus;
 }
 
@@ -242,7 +285,7 @@ static int pci_parse_devaddr(const char *addr, int *domp, 
int *busp, unsigned *s
        return -1;
 
     /* Note: QEMU doesn't implement domains other than 0 */
-    if (dom != 0 || pci_find_bus(bus) == NULL)
+    if (dom != 0 || pci_find_bus(pci_find_host_bus(0), bus) == NULL)
        return -1;
 
     *domp = dom;
@@ -272,7 +315,7 @@ static PCIBus *pci_get_bus_devfn(int *devfnp, const char 
*devaddr)
 
     if (!devaddr) {
         *devfnp = -1;
-        return pci_find_bus(0);
+        return pci_find_bus(pci_find_host_bus(0), 0);
     }
 
     if (pci_parse_devaddr(devaddr, &dom, &bus, &slot) < 0) {
@@ -280,7 +323,7 @@ static PCIBus *pci_get_bus_devfn(int *devfnp, const char 
*devaddr)
     }
 
     *devfnp = slot << 3;
-    return pci_find_bus(bus);
+    return pci_find_bus(pci_find_host_bus(0), bus);
 }
 
 static void pci_init_cmask(PCIDevice *dev)
@@ -577,8 +620,7 @@ void pci_data_write(void *opaque, uint32_t addr, uint32_t 
val, int len)
                 addr, val, len);
 #endif
     bus_num = (addr >> 16) & 0xff;
-    while (s && s->bus_num != bus_num)
-        s = s->next;
+    s = pci_find_bus(s, bus_num);
     if (!s)
         return;
     pci_dev = s->devices[(addr >> 8) & 0xff];
@@ -599,8 +641,7 @@ uint32_t pci_data_read(void *opaque, uint32_t addr, int len)
     uint32_t val;
 
     bus_num = (addr >> 16) & 0xff;
-    while (s && s->bus_num != bus_num)
-        s= s->next;
+    s = pci_find_bus(s, bus_num);
     if (!s)
         goto fail;
     pci_dev = s->devices[(addr >> 8) & 0xff];
@@ -707,7 +748,7 @@ static const pci_class_desc pci_class_descriptions[] =
     { 0, NULL}
 };
 
-static void pci_info_device(PCIDevice *d)
+static void pci_info_device(PCIBus *bus, PCIDevice *d)
 {
     Monitor *mon = cur_mon;
     int i, class;
@@ -774,30 +815,32 @@ static void pci_info_device(PCIDevice *d)
     }
     monitor_printf(mon, "      id \"%s\"\n", d->qdev.id ? d->qdev.id : "");
     if (class == 0x0604 && d->config[0x19] != 0) {
-        pci_for_each_device(d->config[0x19], pci_info_device);
+        pci_for_each_device(bus, d->config[0x19], pci_info_device);
     }
 }
 
-void pci_for_each_device(int bus_num, void (*fn)(PCIDevice *d))
+void pci_for_each_device(PCIBus *bus, int bus_num,
+                         void (*fn)(PCIBus *b, PCIDevice *d))
 {
-    PCIBus *bus = first_bus;
     PCIDevice *d;
     int devfn;
 
-    while (bus && bus->bus_num != bus_num)
-        bus = bus->next;
+    bus = pci_find_bus(bus, bus_num);
     if (bus) {
         for(devfn = 0; devfn < 256; devfn++) {
             d = bus->devices[devfn];
             if (d)
-                fn(d);
+                fn(bus, d);
         }
     }
 }
 
 void pci_info(Monitor *mon)
 {
-    pci_for_each_device(0, pci_info_device);
+    struct PCIHostBus *host;
+    QLIST_FOREACH(host, &host_buses, next) {
+        pci_for_each_device(host->bus, 0, pci_info_device);
+    }
 }
 
 PCIDevice *pci_create(const char *name, const char *devaddr)
@@ -881,22 +924,33 @@ static void pci_bridge_write_config(PCIDevice *d,
 
     pci_default_write_config(d, address, val, len);
     s->bus->bus_num = d->config[PCI_SECONDARY_BUS];
+    s->bus->sub_bus = d->config[PCI_SUBORDINATE_BUS];
 }
 
-PCIBus *pci_find_bus(int bus_num)
+PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
 {
-    PCIBus *bus = first_bus;
+    PCIBus *sec;
 
-    while (bus && bus->bus_num != bus_num)
-        bus = bus->next;
+    if (!bus)
+        return NULL;
 
-    return bus;
+    if (bus->bus_num == bus_num) {
+        return bus;
+    }
+
+    /* try child bus */
+    QLIST_FOREACH(sec, &bus->child, sibling) {
+        if (sec->bus_num <= bus_num && bus_num <= sec->sub_bus) {
+            return pci_find_bus(sec, bus_num);
+        }
+    }
+
+    return NULL;
 }
 
-PCIDevice *pci_find_device(int bus_num, int slot, int function)
+PCIDevice *pci_find_device(PCIBus *bus, int bus_num, int slot, int function)
 {
-    PCIBus *bus = pci_find_bus(bus_num);
-
+    bus = pci_find_bus(bus, bus_num);
     if (!bus)
         return NULL;
 
@@ -904,6 +958,7 @@ PCIDevice *pci_find_device(int bus_num, int slot, int 
function)
 }
 
 PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint16_t vid, uint16_t did,
+                        uint8_t sec_bus, uint8_t sub_bus,
                         pci_map_irq_fn map_irq, const char *name)
 {
     PCIBridge *s;
@@ -925,7 +980,11 @@ PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint16_t 
vid, uint16_t did,
         PCI_HEADER_TYPE_MULTI_FUNCTION | PCI_HEADER_TYPE_BRIDGE; // header_type
     s->dev.config[0x1E] = 0xa0; // secondary status
 
-    s->bus = pci_register_secondary_bus(&s->dev, map_irq, name);
+    assert(sec_bus <= sub_bus);
+    s->dev.config[PCI_SECONDARY_BUS] = sec_bus;
+    s->dev.config[PCI_SUBORDINATE_BUS] = sub_bus;
+
+    s->bus = pci_register_secondary_bus(bus, &s->dev, map_irq, name);
     return s->bus;
 }
 
diff --git a/hw/pci.h b/hw/pci.h
index 0455b30..2737440 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -166,6 +166,9 @@ static inline int pci_bar_is_64bit(const PCIIORegion *r)
 
 #define PCI_COMMAND_RESERVED_MASK_HI (PCI_COMMAND_RESERVED >> 8)
 
+/* Header type 1 (PCI-to-PCI bridges) */
+#define PCI_SUBORDINATE_BUS     0x1a    /* Highest bus number behind the 
bridge */
+
 /* Size of the standard PCI config header */
 #define PCI_CONFIG_HEADER_SIZE 0x40
 /* Size of the standard PCI config space */
@@ -274,15 +277,17 @@ PCIDevice *pci_nic_init(NICInfo *nd, const char 
*default_model,
 void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len);
 uint32_t pci_data_read(void *opaque, uint32_t addr, int len);
 int pci_bus_num(PCIBus *s);
-void pci_for_each_device(int bus_num, void (*fn)(PCIDevice *d));
-PCIBus *pci_find_bus(int bus_num);
-PCIDevice *pci_find_device(int bus_num, int slot, int function);
+void pci_for_each_device(PCIBus *bus, int bus_num, void (*fn)(PCIBus *bus, 
PCIDevice *d));
+PCIBus *pci_find_host_bus(int domain);
+PCIBus *pci_find_bus(PCIBus *bus, int bus_num);
+PCIDevice *pci_find_device(PCIBus *bus, int bus_num, int slot, int function);
 
 int pci_read_devaddr(Monitor *mon, const char *addr, int *domp, int *busp,
                      unsigned *slotp);
 
 void pci_info(Monitor *mon);
 PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint16_t vid, uint16_t did,
+                        uint8_t sec_bus, uint8_t sub_bus,
                         pci_map_irq_fn map_irq, const char *name);
 
 static inline void
-- 
1.6.0.2