arch/arm/kernel/bios32.c

/*
 *  linux/arch/arm/kernel/bios32.c
 *
 *  PCI bios-type initialisation for PCI machines
 *
 *  Bits taken from various places.
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/init.h>

#include <asm/io.h>
#include <asm/mach-types.h>
#include <asm/mach/pci.h>

static int debug_pci;
static int use_firmware;

/*
 * We can't use pci_find_device() here since we are
 * called from interrupt context.
 */
static void pcibios_bus_report_status(struct pci_bus *bus, u_int status_mask, int warn)
{
	struct pci_dev *dev;

	list_for_each_entry(dev, &bus->devices, bus_list) {
		u16 status;

		/*
		 * ignore host bridge - we handle
		 * that separately
		 */
		if (dev->bus->number == 0 && dev->devfn == 0)
			continue;

		pci_read_config_word(dev, PCI_STATUS, &status);
		if (status == 0xffff)
			continue;

		if ((status & status_mask) == 0)
			continue;

		/* clear the status errors */
		pci_write_config_word(dev, PCI_STATUS, status & status_mask);

		if (warn)
			printk("(%s: %04X) ", pci_name(dev), status);
	}

	list_for_each_entry(dev, &bus->devices, bus_list)
		if (dev->subordinate)
			pcibios_bus_report_status(dev->subordinate, status_mask, warn);
}

void pcibios_report_status(u_int status_mask, int warn)
{
	struct list_head *l;

	list_for_each(l, &pci_root_buses) {
		struct pci_bus *bus = pci_bus_b(l);

		pcibios_bus_report_status(bus, status_mask, warn);
	}
}

/*
 * We don't use this to fix the device, but initialisation of it.
 * It's not the correct use for this, but it works.
 * Note that the arbiter/ISA bridge appears to be buggy, specifically in
 * the following area:
 * 1. park on CPU
 * 2. ISA bridge ping-pong
 * 3. ISA bridge master handling of target RETRY
 *
 * Bug 3 is responsible for the sound DMA grinding to a halt.  We now
 * live with bug 2.
 */
static void __devinit pci_fixup_83c553(struct pci_dev *dev)
{
	/*
	 * Set memory region to start at address 0, and enable IO
	 */
	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_SPACE_MEMORY);
	pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_IO);

	dev->resource[0].end -= dev->resource[0].start;
	dev->resource[0].start = 0;

	/*
	 * All memory requests from ISA to be channelled to PCI
	 */
	pci_write_config_byte(dev, 0x48, 0xff);

	/*
	 * Enable ping-pong on bus master to ISA bridge transactions.
	 * This improves the sound DMA substantially.  The fixed
	 * priority arbiter also helps (see below).
	 */
	pci_write_config_byte(dev, 0x42, 0x01);

	/*
	 * Enable PCI retry
	 */
	pci_write_config_byte(dev, 0x40, 0x22);

	/*
	 * We used to set the arbiter to "park on last master" (bit
	 * 1 set), but unfortunately the CyberPro does not park the
	 * bus.  We must therefore park on CPU.  Unfortunately, this
	 * may trigger yet another bug in the 553.
	 */
	pci_write_config_byte(dev, 0x83, 0x02);

	/*
	 * Make the ISA DMA request lowest priority, and disable
	 * rotating priorities completely.
	 */
	pci_write_config_byte(dev, 0x80, 0x11);
	pci_write_config_byte(dev, 0x81, 0x00);

	/*
	 * Route INTA input to IRQ 11, and set IRQ11 to be level
	 * sensitive.
	 */
	pci_write_config_word(dev, 0x44, 0xb000);
	outb(0x08, 0x4d1);
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_83C553, pci_fixup_83c553);

static void __devinit pci_fixup_unassign(struct pci_dev *dev)
{
	dev->resource[0].end -= dev->resource[0].start;
	dev->resource[0].start = 0;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND2, PCI_DEVICE_ID_WINBOND2_89C940F, pci_fixup_unassign);

/*
 * Prevent the PCI layer from seeing the resources allocated to this device
 * if it is the host bridge by marking it as such.  These resources are of
 * no consequence to the PCI layer (they are handled elsewhere).
 */
static void __devinit pci_fixup_dec21285(struct pci_dev *dev)
{
	int i;

	if (dev->devfn == 0) {
		dev->class &= 0xff;
		dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
			dev->resource[i].start = 0;
			dev->resource[i].end   = 0;
			dev->resource[i].flags = 0;
		}
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21285, pci_fixup_dec21285);

/*
 * Same as above. The PrPMC800 carrier board for the PrPMC1100 
 * card maps the host-bridge @ 00:01:00 for some reason and it
 * ends up getting scanned. Note that we only want to do this
 * fixup when we find the IXP4xx on a PrPMC system, which is why
 * we check the machine type. We could be running on a board
 * with an IXP4xx target device and we don't want to kill the
 * resources in that case.
 */
static void __devinit pci_fixup_prpmc1100(struct pci_dev *dev)
{
	int i;

	if (machine_is_prpmc1100()) {
		dev->class &= 0xff;
		dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
			dev->resource[i].start = 0;
			dev->resource[i].end   = 0;
			dev->resource[i].flags = 0;
		}
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IXP4XX, pci_fixup_prpmc1100);

/*
 * PCI IDE controllers use non-standard I/O port decoding, respect it.
 */
static void __devinit pci_fixup_ide_bases(struct pci_dev *dev)
{
	struct resource *r;
	int i;

	if ((dev->class >> 8) != PCI_CLASS_STORAGE_IDE)
		return;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		r = dev->resource + i;
		if ((r->start & ~0x80) == 0x374) {
			r->start |= 2;
			r->end = r->start;
		}
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_ide_bases);

/*
 * Put the DEC21142 to sleep
 */
static void __devinit pci_fixup_dec21142(struct pci_dev *dev)
{
	pci_write_config_dword(dev, 0x40, 0x80000000);
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21142, pci_fixup_dec21142);

/*
 * The CY82C693 needs some rather major fixups to ensure that it does
 * the right thing.  Idea from the Alpha people, with a few additions.
 *
 * We ensure that the IDE base registers are set to 1f0/3f4 for the
 * primary bus, and 170/374 for the secondary bus.  Also, hide them
 * from the PCI subsystem view as well so we won't try to perform
 * our own auto-configuration on them.
 *
 * In addition, we ensure that the PCI IDE interrupts are routed to
 * IRQ 14 and IRQ 15 respectively.
 *
 * The above gets us to a point where the IDE on this device is
 * functional.  However, The CY82C693U _does not work_ in bus
 * master mode without locking the PCI bus solid.
 */
static void __devinit pci_fixup_cy82c693(struct pci_dev *dev)
{
	if ((dev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
		u32 base0, base1;

		if (dev->class & 0x80) {	/* primary */
			base0 = 0x1f0;
			base1 = 0x3f4;
		} else {			/* secondary */
			base0 = 0x170;
			base1 = 0x374;
		}

		pci_write_config_dword(dev, PCI_BASE_ADDRESS_0,
				       base0 | PCI_BASE_ADDRESS_SPACE_IO);
		pci_write_config_dword(dev, PCI_BASE_ADDRESS_1,
				       base1 | PCI_BASE_ADDRESS_SPACE_IO);

		dev->resource[0].start = 0;
		dev->resource[0].end   = 0;
		dev->resource[0].flags = 0;

		dev->resource[1].start = 0;
		dev->resource[1].end   = 0;
		dev->resource[1].flags = 0;
	} else if (PCI_FUNC(dev->devfn) == 0) {
		/*
		 * Setup IDE IRQ routing.
		 */
		pci_write_config_byte(dev, 0x4b, 14);
		pci_write_config_byte(dev, 0x4c, 15);

		/*
		 * Disable FREQACK handshake, enable USB.
		 */
		pci_write_config_byte(dev, 0x4d, 0x41);

		/*
		 * Enable PCI retry, and PCI post-write buffer.
		 */
		pci_write_config_byte(dev, 0x44, 0x17);

		/*
		 * Enable ISA master and DMA post write buffering.
		 */
		pci_write_config_byte(dev, 0x45, 0x03);
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CONTAQ, PCI_DEVICE_ID_CONTAQ_82C693, pci_fixup_cy82c693);

void __devinit pcibios_update_irq(struct pci_dev *dev, int irq)
{
	if (debug_pci)
		printk("PCI: Assigning IRQ %02d to %s\n", irq, pci_name(dev));
	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}

/*
 * If the bus contains any of these devices, then we must not turn on
 * parity checking of any kind.  Currently this is CyberPro 20x0 only.
 */
static inline int pdev_bad_for_parity(struct pci_dev *dev)
{
	return (dev->vendor == PCI_VENDOR_ID_INTERG &&
		(dev->device == PCI_DEVICE_ID_INTERG_2000 ||
		 dev->device == PCI_DEVICE_ID_INTERG_2010));
}

/*
 * Adjust the device resources from bus-centric to Linux-centric.
 */
static void __devinit
pdev_fixup_device_resources(struct pci_sys_data *root, struct pci_dev *dev)
{
	unsigned long offset;
	int i;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		if (dev->resource[i].start == 0)
			continue;
		if (dev->resource[i].flags & IORESOURCE_MEM)
			offset = root->mem_offset;
		else
			offset = root->io_offset;

		dev->resource[i].start += offset;
		dev->resource[i].end   += offset;
	}
}

static void __devinit
pbus_assign_bus_resources(struct pci_bus *bus, struct pci_sys_data *root)
{
	struct pci_dev *dev = bus->self;
	int i;

	if (!dev) {
		/*
		 * Assign root bus resources.
		 */
		for (i = 0; i < 3; i++)
			bus->resource[i] = root->resource[i];
	}
}

/*
 * pcibios_fixup_bus - Called after each bus is probed,
 * but before its children are examined.
 */
void __devinit pcibios_fixup_bus(struct pci_bus *bus)
{
	struct pci_sys_data *root = bus->sysdata;
	struct pci_dev *dev;
	u16 features = PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_FAST_BACK;

	pbus_assign_bus_resources(bus, root);

	/*
	 * Walk the devices on this bus, working out what we can
	 * and can't support.
	 */
	list_for_each_entry(dev, &bus->devices, bus_list) {
		u16 status;

		pdev_fixup_device_resources(root, dev);

		pci_read_config_word(dev, PCI_STATUS, &status);

		/*
		 * If any device on this bus does not support fast back
		 * to back transfers, then the bus as a whole is not able
		 * to support them.  Having fast back to back transfers
		 * on saves us one PCI cycle per transaction.
		 */
		if (!(status & PCI_STATUS_FAST_BACK))
			features &= ~PCI_COMMAND_FAST_BACK;

		if (pdev_bad_for_parity(dev))
			features &= ~(PCI_COMMAND_SERR | PCI_COMMAND_PARITY);

		switch (dev->class >> 8) {
#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
		case PCI_CLASS_BRIDGE_ISA:
		case PCI_CLASS_BRIDGE_EISA:
			/*
			 * If this device is an ISA bridge, set isa_bridge
			 * to point at this device.  We will then go looking
			 * for things like keyboard, etc.
			 */
			isa_bridge = dev;
			break;
#endif
		case PCI_CLASS_BRIDGE_PCI:
			pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &status);
			status |= PCI_BRIDGE_CTL_PARITY|PCI_BRIDGE_CTL_MASTER_ABORT;
			status &= ~(PCI_BRIDGE_CTL_BUS_RESET|PCI_BRIDGE_CTL_FAST_BACK);
			pci_write_config_word(dev, PCI_BRIDGE_CONTROL, status);
			break;

		case PCI_CLASS_BRIDGE_CARDBUS:
			pci_read_config_word(dev, PCI_CB_BRIDGE_CONTROL, &status);
			status |= PCI_CB_BRIDGE_CTL_PARITY|PCI_CB_BRIDGE_CTL_MASTER_ABORT;
			pci_write_config_word(dev, PCI_CB_BRIDGE_CONTROL, status);
			break;
		}
	}

	/*
	 * Now walk the devices again, this time setting them up.
	 */
	list_for_each_entry(dev, &bus->devices, bus_list) {
		u16 cmd;

		pci_read_config_word(dev, PCI_COMMAND, &cmd);
		cmd |= features;
		pci_write_config_word(dev, PCI_COMMAND, cmd);

		pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE,
				      L1_CACHE_BYTES >> 2);
	}

	/*
	 * Propagate the flags to the PCI bridge.
	 */
	if (bus->self && bus->self->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
		if (features & PCI_COMMAND_FAST_BACK)
			bus->bridge_ctl |= PCI_BRIDGE_CTL_FAST_BACK;
		if (features & PCI_COMMAND_PARITY)
			bus->bridge_ctl |= PCI_BRIDGE_CTL_PARITY;
	}

	/*
	 * Report what we did for this bus
	 */
	printk(KERN_INFO "PCI: bus%d: Fast back to back transfers %sabled\n",
		bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");
}

/*
 * Convert from Linux-centric to bus-centric addresses for bridge devices.
 */
void __devinit
pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
			 struct resource *res)
{
	struct pci_sys_data *root = dev->sysdata;
	unsigned long offset = 0;

	if (res->flags & IORESOURCE_IO)
		offset = root->io_offset;
	if (res->flags & IORESOURCE_MEM)
		offset = root->mem_offset;

	region->start = res->start - offset;
	region->end   = res->end - offset;
}

#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(pcibios_fixup_bus);
EXPORT_SYMBOL(pcibios_resource_to_bus);
#endif

/*
 * This is the standard PCI-PCI bridge swizzling algorithm:
 *
 *   Dev: 0  1  2  3
 *    A   A  B  C  D
 *    B   B  C  D  A
 *    C   C  D  A  B
 *    D   D  A  B  C
 *        ^^^^^^^^^^ irq pin on bridge
 */
u8 __devinit pci_std_swizzle(struct pci_dev *dev, u8 *pinp)
{
	int pin = *pinp - 1;

	while (dev->bus->self) {
		pin = (pin + PCI_SLOT(dev->devfn)) & 3;
		/*
		 * move up the chain of bridges,
		 * swizzling as we go.
		 */
		dev = dev->bus->self;
	}
	*pinp = pin + 1;

	return PCI_SLOT(dev->devfn);
}

/*
 * Swizzle the device pin each time we cross a bridge.
 * This might update pin and returns the slot number.
 */
static u8 __devinit pcibios_swizzle(struct pci_dev *dev, u8 *pin)
{
	struct pci_sys_data *sys = dev->sysdata;
	int slot = 0, oldpin = *pin;

	if (sys->swizzle)
		slot = sys->swizzle(dev, pin);

	if (debug_pci)
		printk("PCI: %s swizzling pin %d => pin %d slot %d\n",
			pci_name(dev), oldpin, *pin, slot);

	return slot;
}

/*
 * Map a slot/pin to an IRQ.
 */
static int pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
	struct pci_sys_data *sys = dev->sysdata;
	int irq = -1;

	if (sys->map_irq)
		irq = sys->map_irq(dev, slot, pin);

	if (debug_pci)
		printk("PCI: %s mapping slot %d pin %d => irq %d\n",
			pci_name(dev), slot, pin, irq);

	return irq;
}

static void __init pcibios_init_hw(struct hw_pci *hw)
{
	struct pci_sys_data *sys = NULL;
	int ret;
	int nr, busnr;

	for (nr = busnr = 0; nr < hw->nr_controllers; nr++) {
		sys = kmalloc(sizeof(struct pci_sys_data), GFP_KERNEL);
		if (!sys)
			panic("PCI: unable to allocate sys data!");

		memset(sys, 0, sizeof(struct pci_sys_data));

		sys->hw      = hw;
		sys->busnr   = busnr;
		sys->swizzle = hw->swizzle;
		sys->map_irq = hw->map_irq;
		sys->resource[0] = &ioport_resource;
		sys->resource[1] = &iomem_resource;

		ret = hw->setup(nr, sys);

		if (ret > 0) {
			sys->bus = hw->scan(nr, sys);

			if (!sys->bus)
				panic("PCI: unable to scan bus!");

			busnr = sys->bus->subordinate + 1;

			list_add(&sys->node, &hw->buses);
		} else {
			kfree(sys);
			if (ret < 0)
				break;
		}
	}
}

void __init pci_common_init(struct hw_pci *hw)
{
	struct pci_sys_data *sys;

	INIT_LIST_HEAD(&hw->buses);

	if (hw->preinit)
		hw->preinit();
	pcibios_init_hw(hw);
	if (hw->postinit)
		hw->postinit();

	pci_fixup_irqs(pcibios_swizzle, pcibios_map_irq);

	list_for_each_entry(sys, &hw->buses, node) {
		struct pci_bus *bus = sys->bus;

		if (!use_firmware) {
			/*
			 * Size the bridge windows.
			 */
			pci_bus_size_bridges(bus);

			/*
			 * Assign resources.
			 */
			pci_bus_assign_resources(bus);
		}

		/*
		 * Tell drivers about devices found.
		 */
		pci_bus_add_devices(bus);
	}
}

char * __init pcibios_setup(char *str)
{
	if (!strcmp(str, "debug")) {
		debug_pci = 1;
		return NULL;
	} else if (!strcmp(str, "firmware")) {
		use_firmware = 1;
		return NULL;
	}
	return str;
}

/*
 * From arch/i386/kernel/pci-i386.c:
 *
 * 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 be mirrored at 0x0100-0x03ff..
 */
void pcibios_align_resource(void *data, struct resource *res,
			    unsigned long size, unsigned long align)
{
	unsigned long start = res->start;

	if (res->flags & IORESOURCE_IO && start & 0x300)
		start = (start + 0x3ff) & ~0x3ff;

	res->start = (start + align - 1) & ~(align - 1);
}

/**
 * pcibios_enable_device - Enable I/O and memory.
 * @dev: PCI device to be enabled
 */
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++) {
		/* Only set up the requested stuff */
		if (!(mask & (1 << idx)))
			continue;

		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;
	}

	/*
	 * Bridges (eg, cardbus bridges) need to be fully enabled
	 */
	if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE)
		cmd |= PCI_COMMAND_IO | 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;
}

int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
			enum pci_mmap_state mmap_state, int write_combine)
{
	struct pci_sys_data *root = dev->sysdata;
	unsigned long phys;

	if (mmap_state == pci_mmap_io) {
		return -EINVAL;
	} else {
		phys = vma->vm_pgoff + (root->mem_offset >> PAGE_SHIFT);
	}

	/*
	 * Mark this as IO
	 */
	vma->vm_flags |= VM_SHM | VM_LOCKED | VM_IO;
	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	if (remap_pfn_range(vma, vma->vm_start, phys,
			     vma->vm_end - vma->vm_start,
			     vma->vm_page_prot))
		return -EAGAIN;

	return 0;
}