[PATCH v2 05/19] pci: setup bridges and traverse buses behind them
Lucas Stach
dev at lynxeye.de
Sat Oct 4 10:40:11 PDT 2014
Signed-off-by: Lucas Stach <dev at lynxeye.de>
---
drivers/pci/pci.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++--
include/linux/pci_regs.h | 28 +++++++++++++++
2 files changed, 117 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 115d8a3..59f942d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -211,9 +211,73 @@ static void setup_device(struct pci_dev *dev, int max_bar)
pci_register_device(dev);
}
+static void prescan_setup_bridge(struct pci_dev *dev)
+{
+ u16 cmdstat;
+
+ pci_read_config_word(dev, PCI_COMMAND, &cmdstat);
+
+ /* Configure bus number registers */
+ pci_write_config_byte(dev, PCI_PRIMARY_BUS, dev->bus->number);
+ pci_write_config_byte(dev, PCI_SECONDARY_BUS, dev->subordinate->number);
+ pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, 0xff);
+
+ if (last_mem) {
+ /* Set up memory and I/O filter limits, assume 32-bit I/O space */
+ pci_write_config_word(dev, PCI_MEMORY_BASE,
+ (last_mem & 0xfff00000) >> 16);
+ cmdstat |= PCI_COMMAND_MEMORY;
+ }
+
+ if (last_mem_pref) {
+ /* Set up memory and I/O filter limits, assume 32-bit I/O space */
+ pci_write_config_word(dev, PCI_PREF_MEMORY_BASE,
+ (last_mem_pref & 0xfff00000) >> 16);
+ cmdstat |= PCI_COMMAND_MEMORY;
+ } else {
+
+ /* We don't support prefetchable memory for now, so disable */
+ pci_write_config_word(dev, PCI_PREF_MEMORY_BASE, 0x1000);
+ pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT, 0x0);
+ }
+
+ if (last_io) {
+ pci_write_config_byte(dev, PCI_IO_BASE,
+ (last_io & 0x0000f000) >> 8);
+ pci_write_config_word(dev, PCI_IO_BASE_UPPER16,
+ (last_io & 0xffff0000) >> 16);
+ cmdstat |= PCI_COMMAND_IO;
+ }
+
+ /* Enable memory and I/O accesses, enable bus master */
+ pci_write_config_word(dev, PCI_COMMAND, cmdstat | PCI_COMMAND_MASTER);
+}
+
+static void postscan_setup_bridge(struct pci_dev *dev)
+{
+ /* limit subordinate to last used bus number */
+ pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, bus_index - 1);
+
+ if (last_mem)
+ pci_write_config_word(dev, PCI_MEMORY_LIMIT,
+ ((last_mem - 1) & 0xfff00000) >> 16);
+
+ if (last_mem_pref)
+ pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT,
+ ((last_mem_pref - 1) & 0xfff00000) >> 16);
+
+ if (last_io) {
+ pci_write_config_byte(dev, PCI_IO_LIMIT,
+ ((last_io - 1) & 0x0000f000) >> 8);
+ pci_write_config_word(dev, PCI_IO_LIMIT_UPPER16,
+ ((last_io - 1) & 0xffff0000) >> 16);
+ }
+}
+
unsigned int pci_scan_bus(struct pci_bus *bus)
{
struct pci_dev *dev;
+ struct pci_bus *child_bus;
unsigned int devfn, l, max, class;
unsigned char cmd, tmp, hdr_type, is_multi = 0;
@@ -264,8 +328,8 @@ unsigned int pci_scan_bus(struct pci_bus *bus)
DBG("PCI: %02x:%02x [%04x:%04x]\n", bus->number, dev->devfn,
dev->vendor, dev->device);
- switch (hdr_type & 0x7f) { /* header type */
- case PCI_HEADER_TYPE_NORMAL: /* standard header */
+ switch (hdr_type & 0x7f) {
+ case PCI_HEADER_TYPE_NORMAL:
if (class == PCI_CLASS_BRIDGE_PCI)
goto bad;
@@ -278,7 +342,28 @@ unsigned int pci_scan_bus(struct pci_bus *bus)
setup_device(dev, 6);
break;
- default: /* unknown header */
+ case PCI_HEADER_TYPE_BRIDGE:
+ setup_device(dev, 2);
+
+ child_bus = pci_alloc_bus();
+ /* inherit parent properties */
+ child_bus->host = bus->host;
+ child_bus->ops = bus->host->pci_ops;
+ child_bus->resource[PCI_BUS_RESOURCE_MEM] =
+ bus->resource[PCI_BUS_RESOURCE_MEM];
+ child_bus->resource[PCI_BUS_RESOURCE_MEM_PREF] =
+ bus->resource[PCI_BUS_RESOURCE_MEM_PREF];
+ child_bus->resource[PCI_BUS_RESOURCE_IO] =
+ bus->resource[PCI_BUS_RESOURCE_IO];
+ child_bus->number = bus_index++;
+ list_add_tail(&child_bus->node, &bus->children);
+ dev->subordinate = child_bus;
+
+ prescan_setup_bridge(dev);
+ pci_scan_bus(child_bus);
+ postscan_setup_bridge(dev);
+ break;
+ default:
bad:
printk(KERN_ERR "PCI: %02x:%02x [%04x/%04x/%06x] has unknown header type %02x, ignoring.\n",
bus->number, dev->devfn, dev->vendor, dev->device, class, hdr_type);
@@ -298,6 +383,7 @@ unsigned int pci_scan_bus(struct pci_bus *bus)
*
* Return how far we've got finding sub-buses.
*/
+ max = bus_index;
DBG("PCI: pci_scan_bus returning with max=%02x\n", max);
return max;
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 14a3ed3..8669fc7 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -107,4 +107,32 @@
#define PCI_ROM_ADDRESS_ENABLE 0x01
#define PCI_ROM_ADDRESS_MASK (~0x7ffUL)
+/* Header type 1 (PCI-to-PCI bridges) */
+#define PCI_PRIMARY_BUS 0x18 /* Primary bus number */
+#define PCI_SECONDARY_BUS 0x19 /* Secondary bus number */
+#define PCI_SUBORDINATE_BUS 0x1a /* Highest bus number behind the bridge */
+#define PCI_SEC_LATENCY_TIMER 0x1b /* Latency timer for secondary interface */
+#define PCI_IO_BASE 0x1c /* I/O range behind the bridge */
+#define PCI_IO_LIMIT 0x1d
+#define PCI_IO_RANGE_TYPE_MASK 0x0fUL /* I/O bridging type */
+#define PCI_IO_RANGE_TYPE_16 0x00
+#define PCI_IO_RANGE_TYPE_32 0x01
+#define PCI_IO_RANGE_MASK (~0x0fUL) /* Standard 4K I/O windows */
+#define PCI_IO_1K_RANGE_MASK (~0x03UL) /* Intel 1K I/O windows */
+#define PCI_SEC_STATUS 0x1e /* Secondary status register, only bit 14 used */
+#define PCI_MEMORY_BASE 0x20 /* Memory range behind */
+#define PCI_MEMORY_LIMIT 0x22
+#define PCI_MEMORY_RANGE_TYPE_MASK 0x0fUL
+#define PCI_MEMORY_RANGE_MASK (~0x0fUL)
+#define PCI_PREF_MEMORY_BASE 0x24 /* Prefetchable memory range behind */
+#define PCI_PREF_MEMORY_LIMIT 0x26
+#define PCI_PREF_RANGE_TYPE_MASK 0x0fUL
+#define PCI_PREF_RANGE_TYPE_32 0x00
+#define PCI_PREF_RANGE_TYPE_64 0x01
+#define PCI_PREF_RANGE_MASK (~0x0fUL)
+#define PCI_PREF_BASE_UPPER32 0x28 /* Upper half of prefetchable memory range */
+#define PCI_PREF_LIMIT_UPPER32 0x2c
+#define PCI_IO_BASE_UPPER16 0x30 /* Upper half of I/O addresses */
+#define PCI_IO_LIMIT_UPPER16 0x32
+
#endif /* LINUX_PCI_REGS_H */
--
1.9.3
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