linux/arch/sparc/kernel/leon_pci.c
Bjorn Helgaas 9e808eb6a7 PCI: Cleanup control flow
Return errors immediately so the straightline path is the normal,
no-error path.  No functional change.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-03-19 10:17:22 -05:00

103 lines
2.9 KiB
C

/*
* leon_pci.c: LEON Host PCI support
*
* Copyright (C) 2011 Aeroflex Gaisler AB, Daniel Hellstrom
*
* Code is partially derived from pcic.c
*/
#include <linux/of_device.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/export.h>
#include <asm/leon.h>
#include <asm/leon_pci.h>
/* The LEON architecture does not rely on a BIOS or bootloader to setup
* PCI for us. The Linux generic routines are used to setup resources,
* reset values of configuration-space register settings are preserved.
*
* PCI Memory and Prefetchable Memory is direct-mapped. However I/O Space is
* accessed through a Window which is translated to low 64KB in PCI space, the
* first 4KB is not used so 60KB is available.
*/
void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
{
LIST_HEAD(resources);
struct pci_bus *root_bus;
pci_add_resource_offset(&resources, &info->io_space,
info->io_space.start - 0x1000);
pci_add_resource(&resources, &info->mem_space);
info->busn.flags = IORESOURCE_BUS;
pci_add_resource(&resources, &info->busn);
root_bus = pci_scan_root_bus(&ofdev->dev, 0, info->ops, info,
&resources);
if (!root_bus) {
pci_free_resource_list(&resources);
return;
}
/* Setup IRQs of all devices using custom routines */
pci_fixup_irqs(pci_common_swizzle, info->map_irq);
/* Assign devices with resources */
pci_assign_unassigned_resources();
pci_bus_add_devices(root_bus);
}
void pcibios_fixup_bus(struct pci_bus *pbus)
{
struct pci_dev *dev;
int i, has_io, has_mem;
u16 cmd;
list_for_each_entry(dev, &pbus->devices, bus_list) {
/*
* We can not rely on that the bootloader has enabled I/O
* or memory access to PCI devices. Instead we enable it here
* if the device has BARs of respective type.
*/
has_io = has_mem = 0;
for (i = 0; i < PCI_ROM_RESOURCE; i++) {
unsigned long f = dev->resource[i].flags;
if (f & IORESOURCE_IO)
has_io = 1;
else if (f & IORESOURCE_MEM)
has_mem = 1;
}
/* ROM BARs are mapped into 32-bit memory space */
if (dev->resource[PCI_ROM_RESOURCE].end != 0) {
dev->resource[PCI_ROM_RESOURCE].flags |=
IORESOURCE_ROM_ENABLE;
has_mem = 1;
}
pci_bus_read_config_word(pbus, dev->devfn, PCI_COMMAND, &cmd);
if (has_io && !(cmd & PCI_COMMAND_IO)) {
#ifdef CONFIG_PCI_DEBUG
printk(KERN_INFO "LEONPCI: Enabling I/O for dev %s\n",
pci_name(dev));
#endif
cmd |= PCI_COMMAND_IO;
pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
cmd);
}
if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
#ifdef CONFIG_PCI_DEBUG
printk(KERN_INFO "LEONPCI: Enabling MEMORY for dev"
"%s\n", pci_name(dev));
#endif
cmd |= PCI_COMMAND_MEMORY;
pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
cmd);
}
}
}
resource_size_t pcibios_align_resource(void *data, const struct resource *res,
resource_size_t size, resource_size_t align)
{
return res->start;
}