PCI, of: Move PCI I/O space management to PCI core code

No functional changes in this patch.

PCI I/O space mapping code does not depend on OF; therefore it can be moved
to PCI core code.  This way we will be able to use it, e.g., in ACPI PCI
code.

Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Liviu Dudau <Liviu.Dudau@arm.com>

1 files changed, 115 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 25e0327d4429..bc0c914b8afc 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3021,6 +3021,121 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
 }
 EXPORT_SYMBOL(pci_request_regions_exclusive);
 
+#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_ATOMIC);
+        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 = address - res->start + 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
+}
+
 /**
  *      pci_remap_iospace - Remap the memory mapped I/O space
  *      @res: Resource describing the I/O space