pci root complex: support for tile architecture

This change enables PCI root complex support for TILEPro.  Unlike
TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI
support consists of hypervisor upcalls for PIO, DMA, etc.  However,
the performance is fine for the devices we have tested with so far
(1Gb Ethernet, SATA, etc.).

The <asm/io.h> header was tweaked to be a little bit more aggressive
about disabling attempts to map/unmap IO port space.  The hacky
<asm/pci-bridge.h> header was rolled into the <asm/pci.h> header
and the result was simplified.  Both of the latter two headers were
preliminary versions not meant for release before now - oh well.

There is one quirk for our TILEmpower platform, which accidentally
negotiates up to 5GT and needs to be kicked down to 2.5GT.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/Kconfig

@@ -329,6 +329,18 @@ endmenu  # Tilera-specific configuration
 
 menu "Bus options"
 
+config PCI
+	bool "PCI support"
+	default y
+	select PCI_DOMAINS
+	---help---
+	  Enable PCI root complex support, so PCIe endpoint devices can
+	  be attached to the Tile chip.  Many, but not all, PCI devices
+	  are supported under Tilera's root complex driver.
+
+config PCI_DOMAINS
+	bool
+
 config NO_IOMEM
 	def_bool !PCI
 

arch/tile/include/asm/io.h

@@ -55,9 +55,6 @@ extern void iounmap(volatile void __iomem *addr);
 #define ioremap_writethrough(physaddr, size)	ioremap(physaddr, size)
 #define ioremap_fullcache(physaddr, size)	ioremap(physaddr, size)
 
-void __iomem *ioport_map(unsigned long port, unsigned int len);
-extern inline void ioport_unmap(void __iomem *addr) {}
-
 #define mmiowb()
 
 /* Conversion between virtual and physical mappings.  */
@@ -189,12 +186,22 @@ static inline void memcpy_toio(volatile void __iomem *dst, const void *src,
  * we never run, uses them unconditionally.
  */
 
-static inline int ioport_panic(void)
+static inline long ioport_panic(void)
 {
 	panic("inb/outb and friends do not exist on tile");
 	return 0;
 }
 
+static inline void __iomem *ioport_map(unsigned long port, unsigned int len)
+{
+	return (void __iomem *) ioport_panic();
+}
+
+static inline void ioport_unmap(void __iomem *addr)
+{
+	ioport_panic();
+}
+
 static inline u8 inb(unsigned long addr)
 {
 	return ioport_panic();

arch/tile/include/asm/pci.h

@@ -15,7 +15,29 @@
 #ifndef _ASM_TILE_PCI_H
 #define _ASM_TILE_PCI_H
 
-#include <asm/pci-bridge.h>
+#include <linux/pci.h>
+
+/*
+ * Structure of a PCI controller (host bridge)
+ */
+struct pci_controller {
+	int index;		/* PCI domain number */
+	struct pci_bus *root_bus;
+
+	int first_busno;
+	int last_busno;
+
+	int hv_cfg_fd[2];	/* config{0,1} fds for this PCIe controller */
+	int hv_mem_fd;		/* fd to Hypervisor for MMIO operations */
+
+	struct pci_ops *ops;
+
+	int irq_base;		/* Base IRQ from the Hypervisor	*/
+	int plx_gen1;		/* flag for PLX Gen 1 configuration */
+
+	/* Address ranges that are routed to this controller/bridge. */
+	struct resource mem_resources[3];
+};
 
 /*
  * The hypervisor maps the entirety of CPA-space as bus addresses, so
@@ -24,56 +46,12 @@
  */
 #define PCI_DMA_BUS_IS_PHYS     1
 
-struct pci_controller *pci_bus_to_hose(int bus);
-unsigned char __init common_swizzle(struct pci_dev *dev, unsigned char *pinp);
 int __init tile_pci_init(void);
-void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
-void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
-void __devinit pcibios_fixup_bus(struct pci_bus *bus);
 
-int __devinit _tile_cfg_read(struct pci_controller *hose,
-				    int bus,
-				    int slot,
-				    int function,
-				    int offset,
-				    int size,
-				    u32 *val);
-int __devinit _tile_cfg_write(struct pci_controller *hose,
-				     int bus,
-				     int slot,
-				     int function,
-				     int offset,
-				     int size,
-				     u32 val);
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+static inline void pci_iounmap(struct pci_dev *dev, void __iomem *addr) {}
 
-/*
- * These are used to to config reads and writes in the early stages of
- * setup before the driver infrastructure has been set up enough to be
- * able to do config reads and writes.
- */
-#define early_cfg_read(where, size, value) \
-	_tile_cfg_read(controller, \
-		       current_bus, \
-		       pci_slot, \
-		       pci_fn, \
-		       where, \
-		       size, \
-		       value)
-
-#define early_cfg_write(where, size, value) \
-	_tile_cfg_write(controller, \
-		       current_bus, \
-		       pci_slot, \
-		       pci_fn, \
-		       where, \
-		       size, \
-		       value)
-
-
-
-#define PCICFG_BYTE	1
-#define PCICFG_WORD	2
-#define PCICFG_DWORD	4
+void __devinit pcibios_fixup_bus(struct pci_bus *bus);
 
 #define	TILE_NUM_PCIE	2
 
@@ -88,41 +66,38 @@ static inline int pci_proc_domain(struct pci_bus *bus)
 }
 
 /*
- * I/O space is currently not supported.
+ * pcibios_assign_all_busses() tells whether or not the bus numbers
+ * should be reassigned, in case the BIOS didn't do it correctly, or
+ * in case we don't have a BIOS and we want to let Linux do it.
  */
+static inline int pcibios_assign_all_busses(void)
+{
+	return 1;
+}
 
-#define TILE_PCIE_LOWER_IO		0x0
-#define TILE_PCIE_UPPER_IO		0x10000
-#define TILE_PCIE_PCIE_IO_SIZE		0x0000FFFF
-
-#define _PAGE_NO_CACHE		0
-#define _PAGE_GUARDED		0
-
-
-#define pcibios_assign_all_busses()    pci_assign_all_buses
-extern int pci_assign_all_buses;
-
+/*
+ * No special bus mastering setup handling.
+ */
 static inline void pcibios_set_master(struct pci_dev *dev)
 {
-	/* No special bus mastering setup handling */
 }
 
 #define PCIBIOS_MIN_MEM		0
-#define PCIBIOS_MIN_IO		TILE_PCIE_LOWER_IO
+#define PCIBIOS_MIN_IO		0
 
 /*
  * This flag tells if the platform is TILEmpower that needs
  * special configuration for the PLX switch chip.
  */
-extern int blade_pci;
+extern int tile_plx_gen1;
+
+/* Use any cpu for PCI. */
+#define cpumask_of_pcibus(bus) cpu_online_mask
 
 /* implement the pci_ DMA API in terms of the generic device dma_ one */
 #include <asm-generic/pci-dma-compat.h>
 
 /* generic pci stuff */
 #include <asm-generic/pci.h>
 
-/* Use any cpu for PCI. */
-#define cpumask_of_pcibus(bus) cpu_online_mask
-
 #endif /* _ASM_TILE_PCI_H */

arch/tile/kernel/Makefile

@@ -15,3 +15,4 @@ obj-$(CONFIG_SMP)		+= smpboot.o smp.o tlb.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
+obj-$(CONFIG_PCI)		+= pci.o