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authorLiviu Dudau <Liviu.Dudau@arm.com>2014-09-29 15:29:21 +0100
committerBjorn Helgaas <bhelgaas@google.com>2014-09-30 09:42:45 -0600
commit41f8bba7f5552d033583777dede2df7c36e7853d (patch)
tree5ee6fe856a1cee69e751393fd4068c1a6b5e25e1 /drivers/of
parent112eeaa7f87bbd2925e919486bb504f8954fa675 (diff)
of/pci: Add pci_register_io_range() and pci_pio_to_address()
Some architectures do not have a simple view of the PCI I/O space and instead use a range of CPU addresses that map to bus addresses. For some architectures these ranges will be expressed by OF bindings in a device tree file. This patch introduces a pci_register_io_range() helper function with a generic implementation that can be used by such architectures to keep track of the I/O ranges described by the PCI bindings. If the PCI_IOBASE macro is not defined, that signals lack of support for PCI and we return an error. In order to retrieve the CPU address associated with an I/O port, a new helper function pci_pio_to_address() is introduced. This will search in the list of ranges registered with pci_register_io_range() and return the CPU address that corresponds to the given port. [arnd: add dummy !CONFIG_OF pci_pio_to_address() to fix build errors] Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Rob Herring <robh@kernel.org> CC: Grant Likely <grant.likely@linaro.org>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/address.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c
index e3718250d66e..758d4f04d4aa 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -5,6 +5,8 @@
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/pci_regs.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
#include <linux/string.h>
/* Max address size we deal with */
@@ -601,12 +603,119 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
}
EXPORT_SYMBOL(of_get_address);
+#ifdef PCI_IOBASE
+struct io_range {
+ struct list_head list;
+ phys_addr_t start;
+ resource_size_t size;
+};
+
+static LIST_HEAD(io_range_list);
+static DEFINE_SPINLOCK(io_range_lock);
+#endif
+
+/*
+ * Record the PCI IO range (expressed as CPU physical address + size).
+ * Return a negative value if an error has occured, zero otherwise
+ */
+int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
+{
+ int err = 0;
+
+#ifdef PCI_IOBASE
+ struct io_range *range;
+ resource_size_t allocated_size = 0;
+
+ /* check if the range hasn't been previously recorded */
+ spin_lock(&io_range_lock);
+ list_for_each_entry(range, &io_range_list, list) {
+ if (addr >= range->start && addr + size <= range->start + size) {
+ /* range already registered, bail out */
+ goto end_register;
+ }
+ allocated_size += range->size;
+ }
+
+ /* range not registed yet, check for available space */
+ if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
+ /* if it's too big check if 64K space can be reserved */
+ if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
+ err = -E2BIG;
+ goto end_register;
+ }
+
+ size = SZ_64K;
+ pr_warn("Requested IO range too big, new size set to 64K\n");
+ }
+
+ /* add the range to the list */
+ range = kzalloc(sizeof(*range), GFP_KERNEL);
+ if (!range) {
+ err = -ENOMEM;
+ goto end_register;
+ }
+
+ range->start = addr;
+ range->size = size;
+
+ list_add_tail(&range->list, &io_range_list);
+
+end_register:
+ spin_unlock(&io_range_lock);
+#endif
+
+ return err;
+}
+
+phys_addr_t pci_pio_to_address(unsigned long pio)
+{
+ phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
+
+#ifdef PCI_IOBASE
+ struct io_range *range;
+ resource_size_t allocated_size = 0;
+
+ if (pio > IO_SPACE_LIMIT)
+ return address;
+
+ spin_lock(&io_range_lock);
+ list_for_each_entry(range, &io_range_list, list) {
+ if (pio >= allocated_size && pio < allocated_size + range->size) {
+ address = range->start + pio - allocated_size;
+ break;
+ }
+ allocated_size += range->size;
+ }
+ spin_unlock(&io_range_lock);
+#endif
+
+ return address;
+}
+
unsigned long __weak pci_address_to_pio(phys_addr_t address)
{
+#ifdef PCI_IOBASE
+ struct io_range *res;
+ resource_size_t offset = 0;
+ unsigned long addr = -1;
+
+ spin_lock(&io_range_lock);
+ list_for_each_entry(res, &io_range_list, list) {
+ if (address >= res->start && address < res->start + res->size) {
+ addr = res->start - address + offset;
+ break;
+ }
+ offset += res->size;
+ }
+ spin_unlock(&io_range_lock);
+
+ return addr;
+#else
if (address > IO_SPACE_LIMIT)
return (unsigned long)-1;
return (unsigned long) address;
+#endif
}
static int __of_address_to_resource(struct device_node *dev,