tile PCI RC: support I/O space access

To enable this functionality, configure CONFIG_TILE_PCI_IO.  Without
this flag, the kernel still assigns I/O address ranges to the
devices, but no TRIO resource and mapping support is provided.

We assign disjoint I/O address ranges to separate PCIe domains.

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

arch/tile/include/asm/io.h

@@ -19,7 +19,8 @@
 #include <linux/bug.h>
 #include <asm/page.h>
 
-#define IO_SPACE_LIMIT 0xfffffffful
+/* Maximum PCI I/O space address supported. */
+#define IO_SPACE_LIMIT 0xffffffff
 
 /*
  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
@@ -281,8 +282,108 @@ static inline void memcpy_toio(volatile void __iomem *dst, const void *src,
 
 #endif
 
+#if CHIP_HAS_MMIO() && defined(CONFIG_TILE_PCI_IO)
+
+static inline u8 inb(unsigned long addr)
+{
+	return readb((volatile void __iomem *) addr);
+}
+
+static inline u16 inw(unsigned long addr)
+{
+	return readw((volatile void __iomem *) addr);
+}
+
+static inline u32 inl(unsigned long addr)
+{
+	return readl((volatile void __iomem *) addr);
+}
+
+static inline void outb(u8 b, unsigned long addr)
+{
+	writeb(b, (volatile void __iomem *) addr);
+}
+
+static inline void outw(u16 b, unsigned long addr)
+{
+	writew(b, (volatile void __iomem *) addr);
+}
+
+static inline void outl(u32 b, unsigned long addr)
+{
+	writel(b, (volatile void __iomem *) addr);
+}
+
+static inline void insb(unsigned long addr, void *buffer, int count)
+{
+	if (count) {
+		u8 *buf = buffer;
+		do {
+			u8 x = inb(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+
+static inline void insw(unsigned long addr, void *buffer, int count)
+{
+	if (count) {
+		u16 *buf = buffer;
+		do {
+			u16 x = inw(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+
+static inline void insl(unsigned long addr, void *buffer, int count)
+{
+	if (count) {
+		u32 *buf = buffer;
+		do {
+			u32 x = inl(addr);
+			*buf++ = x;
+		} while (--count);
+	}
+}
+
+static inline void outsb(unsigned long addr, const void *buffer, int count)
+{
+	if (count) {
+		const u8 *buf = buffer;
+		do {
+			outb(*buf++, addr);
+		} while (--count);
+	}
+}
+
+static inline void outsw(unsigned long addr, const void *buffer, int count)
+{
+	if (count) {
+		const u16 *buf = buffer;
+		do {
+			outw(*buf++, addr);
+		} while (--count);
+	}
+}
+
+static inline void outsl(unsigned long addr, const void *buffer, int count)
+{
+	if (count) {
+		const u32 *buf = buffer;
+		do {
+			outl(*buf++, addr);
+		} while (--count);
+	}
+}
+
+extern void __iomem *ioport_map(unsigned long port, unsigned int len);
+extern void ioport_unmap(void __iomem *addr);
+
+#else
+
 /*
- * The Tile architecture does not support IOPORT, even with PCI.
+ * The TilePro architecture does not support IOPORT, even with PCI.
  * Unfortunately we can't yet simply not declare these methods,
  * since some generic code that compiles into the kernel, but
  * we never run, uses them unconditionally.
@@ -290,7 +391,12 @@ static inline void memcpy_toio(volatile void __iomem *dst, const void *src,
 
 static inline long ioport_panic(void)
 {
+#ifdef __tilegx__
+	panic("PCI IO space support is disabled. Configure the kernel with"
+	      " CONFIG_TILE_PCI_IO to enable it");
+#else
 	panic("inb/outb and friends do not exist on tile");
+#endif
 	return 0;
 }
 
@@ -335,13 +441,6 @@ static inline void outl(u32 b, unsigned long addr)
 	ioport_panic();
 }
 
-#define inb_p(addr)	inb(addr)
-#define inw_p(addr)	inw(addr)
-#define inl_p(addr)	inl(addr)
-#define outb_p(x, addr)	outb((x), (addr))
-#define outw_p(x, addr)	outw((x), (addr))
-#define outl_p(x, addr)	outl((x), (addr))
-
 static inline void insb(unsigned long addr, void *buffer, int count)
 {
 	ioport_panic();
@@ -372,6 +471,15 @@ static inline void outsl(unsigned long addr, const void *buffer, int count)
 	ioport_panic();
 }
 
+#endif /* CHIP_HAS_MMIO() && defined(CONFIG_TILE_PCI_IO) */
+
+#define inb_p(addr)	inb(addr)
+#define inw_p(addr)	inw(addr)
+#define inl_p(addr)	inl(addr)
+#define outb_p(x, addr)	outb((x), (addr))
+#define outw_p(x, addr)	outw((x), (addr))
+#define outl_p(x, addr)	outl((x), (addr))
+
 #define ioread16be(addr)	be16_to_cpu(ioread16(addr))
 #define ioread32be(addr)	be32_to_cpu(ioread32(addr))
 #define iowrite16be(v, addr)	iowrite16(be16_to_cpu(v), (addr))

arch/tile/include/asm/pci.h

@@ -144,6 +144,10 @@ struct pci_controller {
 
 	int pio_mem_index;	/* PIO region index for memory access */
 
+#ifdef CONFIG_TILE_PCI_IO
+	int pio_io_index;	/* PIO region index for I/O space access */
+#endif
+
 	/*
 	 * Mem-Map regions for all the memory controllers so that Linux can
 	 * map all of its physical memory space to the PCI bus.
@@ -153,6 +157,10 @@ struct pci_controller {
 	int index;		/* PCI domain number */
 	struct pci_bus *root_bus;
 
+	/* PCI I/O space resource for this controller. */
+	struct resource io_space;
+	char io_space_name[32];
+
 	/* PCI memory space resource for this controller. */
 	struct resource mem_space;
 	char mem_space_name[32];
@@ -210,7 +218,8 @@ static inline int pcibios_assign_all_busses(void)
 }
 
 #define PCIBIOS_MIN_MEM		0
-#define PCIBIOS_MIN_IO		0
+/* Minimum PCI I/O address, starting at the page boundary. */
+#define PCIBIOS_MIN_IO		PAGE_SIZE
 
 /* Use any cpu for PCI. */
 #define cpumask_of_pcibus(bus) cpu_online_mask