1 files changed, 384 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c
new file mode 100644
index 00000000..eb30e356
--- /dev/null
+++ b/arch/xtensa/kernel/pci.c
@@ -0,0 +1,384 @@
+/*
+ * arch/xtensa/kernel/pci.c
+ *
+ * PCI bios-type initialisation for PCI machines
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * Copyright (C) 2001-2005 Tensilica Inc.
+ *
+ * Based largely on work from Cort (ppc/kernel/pci.c)
+ * IO functions copied from sparc.
+ *
+ * Chris Zankel <chris@zankel.net>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/bootmem.h>
+
+#include <asm/pci-bridge.h>
+#include <asm/platform.h>
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(x...) printk(x)
+#else
+#define DBG(x...)
+#endif
+
+/* PCI Controller */
+
+
+/*
+ * pcibios_alloc_controller
+ * pcibios_enable_device
+ * pcibios_fixups
+ * pcibios_align_resource
+ * pcibios_fixup_bus
+ * pcibios_setup
+ * pci_bus_add_device
+ * pci_mmap_page_range
+ */
+
+struct pci_controller* pci_ctrl_head;
+struct pci_controller** pci_ctrl_tail = &pci_ctrl_head;
+
+static int pci_bus_count;
+
+/*
+ * We need to avoid collisions with `mirrored' VGA ports
+ * and other strange ISA hardware, so we always want the
+ * addresses to be allocated in the 0x000-0x0ff region
+ * modulo 0x400.
+ *
+ * Why? Because some silly external IO cards only decode
+ * the low 10 bits of the IO address. The 0x00-0xff region
+ * is reserved for motherboard devices that decode all 16
+ * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
+ * but we want to try to avoid allocating at 0x2900-0x2bff
+ * which might have be mirrored at 0x0100-0x03ff..
+ */
+resource_size_t
+pcibios_align_resource(void *data, const struct resource *res,
+		       resource_size_t size, resource_size_t align)
+{
+	struct pci_dev *dev = data;
+	resource_size_t start = res->start;
+
+	if (res->flags & IORESOURCE_IO) {
+		if (size > 0x100) {
+			printk(KERN_ERR "PCI: I/O Region %s/%d too large"
+			       " (%ld bytes)\n", pci_name(dev),
+			       dev->resource - res, size);
+		}
+
+		if (start & 0x300)
+			start = (start + 0x3ff) & ~0x3ff;
+	}
+
+	return start;
+}
+
+int
+pcibios_enable_resources(struct pci_dev *dev, int mask)
+{
+	u16 cmd, old_cmd;
+	int idx;
+	struct resource *r;
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	old_cmd = cmd;
+	for(idx=0; idx<6; idx++) {
+		r = &dev->resource[idx];
+		if (!r->start && r->end) {
+			printk (KERN_ERR "PCI: Device %s not available because "
+				"of resource collisions\n", pci_name(dev));
+			return -EINVAL;
+		}
+		if (r->flags & IORESOURCE_IO)
+			cmd |= PCI_COMMAND_IO;
+		if (r->flags & IORESOURCE_MEM)
+			cmd |= PCI_COMMAND_MEMORY;
+	}
+	if (dev->resource[PCI_ROM_RESOURCE].start)
+		cmd |= PCI_COMMAND_MEMORY;
+	if (cmd != old_cmd) {
+		printk("PCI: Enabling device %s (%04x -> %04x)\n",
+			pci_name(dev), old_cmd, cmd);
+		pci_write_config_word(dev, PCI_COMMAND, cmd);
+	}
+	return 0;
+}
+
+struct pci_controller * __init pcibios_alloc_controller(void)
+{
+	struct pci_controller *pci_ctrl;
+
+	pci_ctrl = (struct pci_controller *)alloc_bootmem(sizeof(*pci_ctrl));
+	memset(pci_ctrl, 0, sizeof(struct pci_controller));
+
+	*pci_ctrl_tail = pci_ctrl;
+	pci_ctrl_tail = &pci_ctrl->next;
+
+	return pci_ctrl;
+}
+
+static void __init pci_controller_apertures(struct pci_controller *pci_ctrl,
+					    struct list_head *resources)
+{
+	struct resource *res;
+	unsigned long io_offset;
+	int i;
+
+	io_offset = (unsigned long)pci_ctrl->io_space.base;
+	res = &pci_ctrl->io_resource;
+	if (!res->flags) {
+		if (io_offset)
+			printk (KERN_ERR "I/O resource not set for host"
+				" bridge %d\n", pci_ctrl->index);
+		res->start = 0;
+		res->end = IO_SPACE_LIMIT;
+		res->flags = IORESOURCE_IO;
+	}
+	res->start += io_offset;
+	res->end += io_offset;
+	pci_add_resource_offset(resources, res, io_offset);
+
+	for (i = 0; i < 3; i++) {
+		res = &pci_ctrl->mem_resources[i];
+		if (!res->flags) {
+			if (i > 0)
+				continue;
+			printk(KERN_ERR "Memory resource not set for "
+			       "host bridge %d\n", pci_ctrl->index);
+			res->start = 0;
+			res->end = ~0U;
+			res->flags = IORESOURCE_MEM;
+		}
+		pci_add_resource(resources, res);
+	}
+}
+
+static int __init pcibios_init(void)
+{
+	struct pci_controller *pci_ctrl;
+	struct list_head resources;
+	struct pci_bus *bus;
+	int next_busno = 0, i;
+
+	printk("PCI: Probing PCI hardware\n");
+
+	/* Scan all of the recorded PCI controllers.  */
+	for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
+		pci_ctrl->last_busno = 0xff;
+		INIT_LIST_HEAD(&resources);
+		pci_controller_apertures(pci_ctrl, &resources);
+		bus = pci_scan_root_bus(NULL, pci_ctrl->first_busno,
+					pci_ctrl->ops, pci_ctrl, &resources);
+		pci_ctrl->bus = bus;
+		pci_ctrl->last_busno = bus->subordinate;
+		if (next_busno <= pci_ctrl->last_busno)
+			next_busno = pci_ctrl->last_busno+1;
+	}
+	pci_bus_count = next_busno;
+
+	return platform_pcibios_fixup();
+}
+
+subsys_initcall(pcibios_init);
+
+void __init pcibios_fixup_bus(struct pci_bus *bus)
+{
+	if (bus->parent) {
+		/* This is a subordinate bridge */
+		pci_read_bridge_bases(bus);
+	}
+}
+
+char __init *pcibios_setup(char *str)
+{
+	return str;
+}
+
+void pcibios_set_master(struct pci_dev *dev)
+{
+	/* No special bus mastering setup handling */
+}
+
+/* the next one is stolen from the alpha port... */
+
+void __init
+pcibios_update_irq(struct pci_dev *dev, int irq)
+{
+	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
+}
+
+int pcibios_enable_device(struct pci_dev *dev, int mask)
+{
+	u16 cmd, old_cmd;
+	int idx;
+	struct resource *r;
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	old_cmd = cmd;
+	for (idx=0; idx<6; idx++) {
+		r = &dev->resource[idx];
+		if (!r->start && r->end) {
+			printk(KERN_ERR "PCI: Device %s not available because "
+			       "of resource collisions\n", pci_name(dev));
+			return -EINVAL;
+		}
+		if (r->flags & IORESOURCE_IO)
+			cmd |= PCI_COMMAND_IO;
+		if (r->flags & IORESOURCE_MEM)
+			cmd |= PCI_COMMAND_MEMORY;
+	}
+	if (cmd != old_cmd) {
+		printk("PCI: Enabling device %s (%04x -> %04x)\n",
+		       pci_name(dev), old_cmd, cmd);
+		pci_write_config_word(dev, PCI_COMMAND, cmd);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+
+/*
+ * Return the index of the PCI controller for device pdev.
+ */
+
+int
+pci_controller_num(struct pci_dev *dev)
+{
+	struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata;
+	return pci_ctrl->index;
+}
+
+#endif /* CONFIG_PROC_FS */
+
+/*
+ * Platform support for /proc/bus/pci/X/Y mmap()s,
+ * modelled on the sparc64 implementation by Dave Miller.
+ *  -- paulus.
+ */
+
+/*
+ * Adjust vm_pgoff of VMA such that it is the physical page offset
+ * corresponding to the 32-bit pci bus offset for DEV requested by the user.
+ *
+ * Basically, the user finds the base address for his device which he wishes
+ * to mmap.  They read the 32-bit value from the config space base register,
+ * add whatever PAGE_SIZE multiple offset they wish, and feed this into the
+ * offset parameter of mmap on /proc/bus/pci/XXX for that device.
+ *
+ * Returns negative error code on failure, zero on success.
+ */
+static __inline__ int
+__pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma,
+		       enum pci_mmap_state mmap_state)
+{
+	struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata;
+	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+	unsigned long io_offset = 0;
+	int i, res_bit;
+
+	if (pci_ctrl == 0)
+		return -EINVAL;		/* should never happen */
+
+	/* If memory, add on the PCI bridge address offset */
+	if (mmap_state == pci_mmap_mem) {
+		res_bit = IORESOURCE_MEM;
+	} else {
+		io_offset = (unsigned long)pci_ctrl->io_space.base;
+		offset += io_offset;
+		res_bit = IORESOURCE_IO;
+	}
+
+	/*
+	 * Check that the offset requested corresponds to one of the
+	 * resources of the device.
+	 */
+	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
+		struct resource *rp = &dev->resource[i];
+		int flags = rp->flags;
+
+		/* treat ROM as memory (should be already) */
+		if (i == PCI_ROM_RESOURCE)
+			flags |= IORESOURCE_MEM;
+
+		/* Active and same type? */
+		if ((flags & res_bit) == 0)
+			continue;
+
+		/* In the range of this resource? */
+		if (offset < (rp->start & PAGE_MASK) || offset > rp->end)
+			continue;
+
+		/* found it! construct the final physical address */
+		if (mmap_state == pci_mmap_io)
+			offset += pci_ctrl->io_space.start - io_offset;
+		vma->vm_pgoff = offset >> PAGE_SHIFT;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
+ * device mapping.
+ */
+static __inline__ void
+__pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,
+		      enum pci_mmap_state mmap_state, int write_combine)
+{
+	int prot = pgprot_val(vma->vm_page_prot);
+
+	/* Set to write-through */
+	prot &= ~_PAGE_NO_CACHE;
+#if 0
+	if (!write_combine)
+		prot |= _PAGE_WRITETHRU;
+#endif
+	vma->vm_page_prot = __pgprot(prot);
+}
+
+/*
+ * Perform the actual remap of the pages for a PCI device mapping, as
+ * appropriate for this architecture.  The region in the process to map
+ * is described by vm_start and vm_end members of VMA, the base physical
+ * address is found in vm_pgoff.
+ * The pci device structure is provided so that architectures may make mapping
+ * decisions on a per-device or per-bus basis.
+ *
+ * Returns a negative error code on failure, zero on success.
+ */
+int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
+			enum pci_mmap_state mmap_state,
+			int write_combine)
+{
+	int ret;
+
+	ret = __pci_mmap_make_offset(dev, vma, mmap_state);
+	if (ret < 0)
+		return ret;
+
+	__pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine);
+
+	ret = io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+			         vma->vm_end - vma->vm_start,vma->vm_page_prot);
+
+	return ret;
+}