[PATCH 09/20] tile PCI RC: support I/O space access

From: Chris Metcalf
Date: Mon Aug 05 2013 - 16:43:12 EST


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@xxxxxxxxxx>
---
arch/tile/Kconfig | 10 ++++
arch/tile/include/asm/io.h | 126 +++++++++++++++++++++++++++++++++++++++----
arch/tile/include/asm/pci.h | 11 +++-
arch/tile/kernel/pci_gx.c | 128 +++++++++++++++++++++++++++++++++++++++++---
4 files changed, 257 insertions(+), 18 deletions(-)

diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 24565a7..bfff769 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -396,6 +396,16 @@ config NO_IOMEM
config NO_IOPORT
def_bool !PCI

+config TILE_PCI_IO
+ bool "PCI I/O space support"
+ default n
+ depends on PCI
+ depends on TILEGX
+ ---help---
+ Enable PCI I/O space support on TILEGx. Since the PCI I/O space
+ is used by few modern PCIe endpoint devices, its support is disabled
+ by default to save the TRIO PIO Region resource for other purposes.
+
source "drivers/pci/Kconfig"

config TILE_USB
diff --git a/arch/tile/include/asm/io.h b/arch/tile/include/asm/io.h
index 3167291..73b319e 100644
--- a/arch/tile/include/asm/io.h
+++ b/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))
diff --git a/arch/tile/include/asm/pci.h b/arch/tile/include/asm/pci.h
index cd10e65..9cf5308 100644
--- a/arch/tile/include/asm/pci.h
+++ b/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
diff --git a/arch/tile/kernel/pci_gx.c b/arch/tile/kernel/pci_gx.c
index bf8c69d..fde3589 100644
--- a/arch/tile/kernel/pci_gx.c
+++ b/arch/tile/kernel/pci_gx.c
@@ -77,6 +77,9 @@ static int rc_delay[TILEGX_NUM_TRIO][TILEGX_TRIO_PCIES];
/* Default number of seconds that the PCIe RC port probe can be delayed. */
#define DEFAULT_RC_DELAY 10

+/* The PCI I/O space size in each PCI domain. */
+#define IO_SPACE_SIZE 0x10000
+
/* Array of the PCIe ports configuration info obtained from the BIB. */
struct pcie_port_property pcie_ports[TILEGX_NUM_TRIO][TILEGX_TRIO_PCIES];

@@ -421,6 +424,17 @@ out:
controller->index = i;
controller->ops = &tile_cfg_ops;

+ controller->io_space.start = PCIBIOS_MIN_IO +
+ (i * IO_SPACE_SIZE);
+ controller->io_space.end = controller->io_space.start +
+ IO_SPACE_SIZE - 1;
+ BUG_ON(controller->io_space.end > IO_SPACE_LIMIT);
+ controller->io_space.flags = IORESOURCE_IO;
+ snprintf(controller->io_space_name,
+ sizeof(controller->io_space_name),
+ "PCI I/O domain %d", i);
+ controller->io_space.name = controller->io_space_name;
+
/*
* The PCI memory resource is located above the PA space.
* For every host bridge, the BAR window or the MMIO aperture
@@ -861,17 +875,16 @@ int __init pcibios_init(void)
/*
* The PCI memory resource is located above the PA space.
* The memory range for the PCI root bus should not overlap
- * with the physical RAM
+ * with the physical RAM.
*/
pci_add_resource_offset(&resources, &controller->mem_space,
controller->mem_offset);
-
+ pci_add_resource(&resources, &controller->io_space);
controller->first_busno = next_busno;
bus = pci_scan_root_bus(NULL, next_busno, controller->ops,
controller, &resources);
controller->root_bus = bus;
next_busno = bus->busn_res.end + 1;
-
}

/* Do machine dependent PCI interrupt routing */
@@ -915,9 +928,9 @@ int __init pcibios_init(void)
pci_controllers[i].mem_resources[0] =
*next_bus->resource[0];
pci_controllers[i].mem_resources[1] =
- *next_bus->resource[1];
+ *next_bus->resource[1];
pci_controllers[i].mem_resources[2] =
- *next_bus->resource[2];
+ *next_bus->resource[2];

break;
}
@@ -967,6 +980,39 @@ int __init pcibios_init(void)
continue;
}

+#ifdef CONFIG_TILE_PCI_IO
+ /*
+ * Alloc a PIO region for PCI I/O space access for each RC port.
+ */
+ ret = gxio_trio_alloc_pio_regions(trio_context, 1, 0, 0);
+ if (ret < 0) {
+ pr_err("PCI: I/O PIO alloc failure on TRIO %d mac %d, "
+ "give up\n", controller->trio_index,
+ controller->mac);
+
+ continue;
+ }
+
+ controller->pio_io_index = ret;
+
+ /*
+ * For PIO IO, the bus_address_hi parameter is hard-coded 0
+ * because PCI I/O address space is 32-bit.
+ */
+ ret = gxio_trio_init_pio_region_aux(trio_context,
+ controller->pio_io_index,
+ controller->mac,
+ 0,
+ HV_TRIO_PIO_FLAG_IO_SPACE);
+ if (ret < 0) {
+ pr_err("PCI: I/O PIO init failure on TRIO %d mac %d, "
+ "give up\n", controller->trio_index,
+ controller->mac);
+
+ continue;
+ }
+#endif
+
/*
* Configure a Mem-Map region for each memory controller so
* that Linux can map all of its PA space to the PCI bus.
@@ -1052,8 +1098,7 @@ char *pcibios_setup(char *str)

/*
* Enable memory address decoding, as appropriate, for the
- * device described by the 'dev' struct. The I/O decoding
- * is disabled, though the TILE-Gx supports I/O addressing.
+ * device described by the 'dev' struct.
*
* This is called from the generic PCI layer, and can be called
* for bridges or endpoints.
@@ -1134,10 +1179,77 @@ got_it:
* We need to keep the PCI bus address's in-page offset in the VA.
*/
return iorpc_ioremap(trio_fd, offset, size) +
- (phys_addr & (PAGE_SIZE - 1));
+ (start & (PAGE_SIZE - 1));
}
EXPORT_SYMBOL(ioremap);

+#ifdef CONFIG_TILE_PCI_IO
+/* Map a PCI I/O address into VA space. */
+void __iomem *ioport_map(unsigned long port, unsigned int size)
+{
+ struct pci_controller *controller = NULL;
+ resource_size_t bar_start;
+ resource_size_t bar_end;
+ resource_size_t offset;
+ resource_size_t start;
+ resource_size_t end;
+ int trio_fd;
+ int i;
+
+ start = port;
+ end = port + size - 1;
+
+ /*
+ * In the following, each PCI controller's mem_resources[0]
+ * represents its PCI I/O resource. By searching port in each
+ * controller's mem_resources[0], we can determine the controller
+ * that should accept the PCI I/O access.
+ */
+
+ for (i = 0; i < num_rc_controllers; i++) {
+ /*
+ * Skip controllers that are not properly initialized or
+ * have down links.
+ */
+ if (pci_controllers[i].root_bus == NULL)
+ continue;
+
+ bar_start = pci_controllers[i].mem_resources[0].start;
+ bar_end = pci_controllers[i].mem_resources[0].end;
+
+ if ((start >= bar_start) && (end <= bar_end)) {
+
+ controller = &pci_controllers[i];
+
+ goto got_it;
+ }
+ }
+
+ if (controller == NULL)
+ return NULL;
+
+got_it:
+ trio_fd = controller->trio->fd;
+
+ /* Convert the resource start to the bus address offset. */
+ port -= controller->io_space.start;
+
+ offset = HV_TRIO_PIO_OFFSET(controller->pio_io_index) + port;
+
+ /*
+ * We need to keep the PCI bus address's in-page offset in the VA.
+ */
+ return iorpc_ioremap(trio_fd, offset, size) + (port & (PAGE_SIZE - 1));
+}
+EXPORT_SYMBOL(ioport_map);
+
+void ioport_unmap(void __iomem *addr)
+{
+ iounmap(addr);
+}
+EXPORT_SYMBOL(ioport_unmap);
+#endif
+
void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
{
iounmap(addr);
--
1.8.3.1

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