[PATCH v2 08/27] pci: implement an emulated PCI-to-PCI bridge
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Mon Jan 28 13:56:17 EST 2013
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
drivers/pci/Kconfig | 3 +
drivers/pci/Makefile | 1 +
drivers/pci/sw-pci-pci-bridge.c | 185 +++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 43 +++++++++
4 files changed, 232 insertions(+)
create mode 100644 drivers/pci/sw-pci-pci-bridge.c
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index f7548e2..6ed3db1 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -122,3 +122,6 @@ config PCI_LABEL
config PCI_SW_HOST_BRIDGE
bool
+
+config PCI_SW_PCI_PCI_BRIDGE
+ bool
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 44ce914..5b48961 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_PCI_IOAPIC) += ioapic.o
# Emulated PCI elements
obj-$(CONFIG_PCI_SW_HOST_BRIDGE) += sw-host-bridge.o
+obj-$(CONFIG_PCI_SW_PCI_PCI_BRIDGE) += sw-pci-pci-bridge.o
# Build the PCI Hotplug drivers if we were asked to
obj-$(CONFIG_HOTPLUG_PCI) += hotplug/
diff --git a/drivers/pci/sw-pci-pci-bridge.c b/drivers/pci/sw-pci-pci-bridge.c
new file mode 100644
index 0000000..25679cc
--- /dev/null
+++ b/drivers/pci/sw-pci-pci-bridge.c
@@ -0,0 +1,185 @@
+/*
+ * Implementation of a simple emulated PCI-to-PCI bridge.
+ *
+ * Thierry Reding <thierry.reding at avionic-design.de>
+ * Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+
+int pci_sw_pci_bridge_init(struct pci_sw_pci_bridge *bridge)
+{
+ if (!bridge)
+ return -EINVAL;
+
+ memset(bridge, 0, sizeof(struct pci_sw_pci_bridge));
+
+ bridge->status = PCI_STATUS_CAP_LIST;
+ bridge->class = PCI_CLASS_BRIDGE_PCI;
+ bridge->header_type = PCI_HEADER_TYPE_BRIDGE;
+ bridge->cache_line_size = 0x10;
+
+ /* We support 32 bits I/O addressing */
+ bridge->iobase = PCI_IO_RANGE_TYPE_32;
+ bridge->iolimit = PCI_IO_RANGE_TYPE_32;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_sw_pci_bridge_init);
+
+int pci_sw_pci_bridge_read(struct pci_sw_pci_bridge *bridge,
+ unsigned int where, int size, u32 *value)
+{
+ switch (where & ~3) {
+ case PCI_VENDOR_ID:
+ *value = bridge->device << 16 | bridge->vendor;
+ break;
+
+ case PCI_COMMAND:
+ *value = bridge->status << 16 | bridge->command;
+ break;
+
+ case PCI_CLASS_REVISION:
+ *value = bridge->class << 16 | bridge->interface << 8 |
+ bridge->revision;
+ break;
+
+ case PCI_CACHE_LINE_SIZE:
+ *value = bridge->bist << 24 | bridge->header_type << 16 |
+ bridge->latency_timer << 8 | bridge->cache_line_size;
+ break;
+
+ case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1:
+ *value = bridge->bar[((where & ~3) - PCI_BASE_ADDRESS_0) / 4];
+ break;
+
+ case PCI_PRIMARY_BUS:
+ *value = (bridge->secondary_latency_timer << 24 |
+ bridge->subordinate_bus << 16 |
+ bridge->secondary_bus << 8 |
+ bridge->primary_bus);
+ break;
+
+ case PCI_IO_BASE:
+ *value = (bridge->secondary_status << 16 |
+ bridge->iolimit << 8 |
+ bridge->iobase);
+ break;
+
+ case PCI_MEMORY_BASE:
+ *value = (bridge->memlimit << 16 | bridge->membase);
+ break;
+
+ case PCI_PREF_MEMORY_BASE:
+ *value = (bridge->prefmemlimit << 16 | bridge->prefmembase);
+ break;
+
+ case PCI_PREF_BASE_UPPER32:
+ *value = bridge->prefbaseupper;
+ break;
+
+ case PCI_PREF_LIMIT_UPPER32:
+ *value = bridge->preflimitupper;
+ break;
+
+ case PCI_IO_BASE_UPPER16:
+ *value = (bridge->iolimitupper << 16 | bridge->iobaseupper);
+ break;
+
+ case PCI_ROM_ADDRESS1:
+ *value = 0;
+ break;
+
+ default:
+ *value = 0xffffffff;
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ }
+
+ if (size == 2)
+ *value = (*value >> (8 * (where & 3))) & 0xffff;
+ else if (size == 1)
+ *value = (*value >> (8 * (where & 3))) & 0xff;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+EXPORT_SYMBOL_GPL(pci_sw_pci_bridge_read);
+
+int pci_sw_pci_bridge_write(struct pci_sw_pci_bridge *bridge,
+ unsigned int where, int size, u32 value)
+{
+ u32 mask, reg;
+ int err;
+
+ if (size == 4)
+ mask = 0x0;
+ else if (size == 2)
+ mask = ~(0xffff << ((where & 3) * 8));
+ else if (size == 1)
+ mask = ~(0xff << ((where & 3) * 8));
+ else
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ err = pci_sw_pci_bridge_read(bridge, where & ~3, 4, ®);
+ if (err)
+ return err;
+
+ value = (reg & mask) | value << ((where & 3) * 8);
+
+ switch (where & ~3) {
+ case PCI_COMMAND:
+ bridge->command = value & 0xffff;
+ bridge->status = value >> 16;
+ break;
+
+ case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1:
+ bridge->bar[((where & ~3) - PCI_BASE_ADDRESS_0) / 4] = value;
+ break;
+
+ case PCI_IO_BASE:
+ /*
+ * We also keep bit 1 set, it is a read-only bit that
+ * indicates we support 32 bits addressing for the
+ * I/O
+ */
+ bridge->iobase = (value & 0xff) | PCI_IO_RANGE_TYPE_32;
+ bridge->iolimit = ((value >> 8) & 0xff) | PCI_IO_RANGE_TYPE_32;
+ bridge->secondary_status = value >> 16;
+ break;
+
+ case PCI_MEMORY_BASE:
+ bridge->membase = value & 0xffff;
+ bridge->memlimit = value >> 16;
+ break;
+
+ case PCI_PREF_MEMORY_BASE:
+ bridge->prefmembase = value & 0xffff;
+ bridge->prefmemlimit = value >> 16;
+ break;
+
+ case PCI_PREF_BASE_UPPER32:
+ bridge->prefbaseupper = value;
+ break;
+
+ case PCI_PREF_LIMIT_UPPER32:
+ bridge->preflimitupper = value;
+ break;
+
+ case PCI_IO_BASE_UPPER16:
+ bridge->iobaseupper = value & 0xffff;
+ bridge->iolimitupper = value >> 16;
+ break;
+
+ default:
+ break;
+ }
+
+ return PCIBIOS_SUCCESSFUL;
+}
+EXPORT_SYMBOL_GPL(pci_sw_pci_bridge_write);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c93e258..b83b4c8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1864,4 +1864,47 @@ extern int pci_sw_host_bridge_read(struct pci_sw_host_bridge *bridge,
extern int pci_sw_host_bridge_write(struct pci_sw_host_bridge *bridge,
unsigned int where, int size, u32 value);
+struct pci_sw_pci_bridge {
+ u16 vendor;
+ u16 device;
+ u16 command;
+ u16 status;
+ u16 class;
+ u8 interface;
+ u8 revision;
+ u8 bist;
+ u8 header_type;
+ u8 latency_timer;
+ u8 cache_line_size;
+ u32 bar[2];
+ u8 primary_bus;
+ u8 secondary_bus;
+ u8 subordinate_bus;
+ u8 secondary_latency_timer;
+ u8 iobase;
+ u8 iolimit;
+ u16 secondary_status;
+ u16 membase;
+ u16 memlimit;
+ u16 prefmembase;
+ u16 prefmemlimit;
+ u32 prefbaseupper;
+ u32 preflimitupper;
+ u16 iobaseupper;
+ u16 iolimitupper;
+ u8 cappointer;
+ u8 reserved1;
+ u16 reserved2;
+ u32 romaddr;
+ u8 intline;
+ u8 intpin;
+ u16 bridgectrl;
+};
+
+extern int pci_sw_pci_bridge_init(struct pci_sw_pci_bridge *bridge);
+extern int pci_sw_pci_bridge_read(struct pci_sw_pci_bridge *bridge,
+ unsigned int where, int size, u32 *value);
+extern int pci_sw_pci_bridge_write(struct pci_sw_pci_bridge *bridge,
+ unsigned int where, int size, u32 value);
+
#endif /* LINUX_PCI_H */
--
1.7.9.5
More information about the linux-arm-kernel
mailing list