[PATCH v7 2/6] pci: OF: Fix the conversion of IO ranges into IO resources.

From: Liviu Dudau
Date: Fri Mar 14 2014 - 11:37:43 EST


The ranges property for a host bridge controller in DT describes
the mapping between the PCI bus address and the CPU physical address.
The resources framework however expects that the IO resources start
at a pseudo "port" address 0 (zero) and have a maximum size of IO_SPACE_LIMIT.
The conversion from pci ranges to resources failed to take that into account.

In the process move the function into drivers/of/address.c as it now
depends on pci_address_to_pio() code and make it return an error message.

Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
Tested-by: Tanmay Inamdar <tinamdar@xxxxxxx>
---
drivers/of/address.c | 40 ++++++++++++++++++++++++++++++++++++
include/linux/of_address.h | 13 ++----------
2 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index be958ed..4eabd30 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -728,3 +728,43 @@ void __iomem *of_iomap(struct device_node *np, int index)
return ioremap(res.start, resource_size(&res));
}
EXPORT_SYMBOL(of_iomap);
+
+/**
+ * of_pci_range_to_resource - Create a resource from an of_pci_range
+ * @range: the PCI range that describes the resource
+ * @np: device node where the range belongs to
+ * @res: pointer to a valid resource that will be updated to
+ * reflect the values contained in the range.
+ *
+ * Returns EINVAL if the range cannot be converted to resource.
+ *
+ * Note that if the range is an IO range, the resource will be converted
+ * using pci_address_to_pio() which can fail if it is called too early or
+ * if the range cannot be matched to any host bridge IO space (our case here).
+ * To guard against that we try to register the IO range first.
+ * If that fails we know that pci_address_to_pio() will do too.
+ */
+int of_pci_range_to_resource(struct of_pci_range *range,
+ struct device_node *np, struct resource *res)
+{
+ res->flags = range->flags;
+ if (res->flags & IORESOURCE_IO) {
+ unsigned long port = -1;
+ int err = pci_register_io_range(range->cpu_addr, range->size);
+ if (err)
+ return err;
+ port = pci_address_to_pio(range->cpu_addr);
+ if (port == (unsigned long)-1) {
+ res->start = (resource_size_t)OF_BAD_ADDR;
+ res->end = (resource_size_t)OF_BAD_ADDR;
+ return -EINVAL;
+ }
+ res->start = port;
+ } else {
+ res->start = range->cpu_addr;
+ }
+ res->end = res->start + range->size - 1;
+ res->parent = res->child = res->sibling = NULL;
+ res->name = np->full_name;
+ return 0;
+}
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 40c418d..a4b400d 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -23,17 +23,8 @@ struct of_pci_range {
#define for_each_of_pci_range(parser, range) \
for (; of_pci_range_parser_one(parser, range);)

-static inline void of_pci_range_to_resource(struct of_pci_range *range,
- struct device_node *np,
- struct resource *res)
-{
- res->flags = range->flags;
- res->start = range->cpu_addr;
- res->end = range->cpu_addr + range->size - 1;
- res->parent = res->child = res->sibling = NULL;
- res->name = np->full_name;
-}
-
+extern int of_pci_range_to_resource(struct of_pci_range *range,
+ struct device_node *np, struct resource *res);
/* Translate a DMA address from device space to CPU space */
extern u64 of_translate_dma_address(struct device_node *dev,
const __be32 *in_addr);
--
1.9.0

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