cleanup IORESOURCE_CACHEABLE vs ioremap()

Quoting Arnd:
    I was thinking the opposite approach and basically removing all uses
    of IORESOURCE_CACHEABLE from the kernel. There are only a handful of
    them.and we can probably replace them all with hardcoded
    ioremap_cached() calls in the cases they are actually useful.

All existing usages of IORESOURCE_CACHEABLE call ioremap() instead of
ioremap_nocache() if the resource is cacheable, however ioremap() is
uncached by default. Clearly none of the existing usages care about the
cacheability. Particularly devm_ioremap_resource() never worked as
advertised since it always fell back to plain ioremap().

Clean this up as the new direction we want is to convert
ioremap_<type>() usages to memremap(..., flags).

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/lib/devres.c b/lib/devres.c
index fbe2aac522e6..f13a2468ff39 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -119,10 +119,9 @@ EXPORT_SYMBOL(devm_iounmap);
  * @dev: generic device to handle the resource for
  * @res: resource to be handled
  *
- * Checks that a resource is a valid memory region, requests the memory region
- * and ioremaps it either as cacheable or as non-cacheable memory depending on
- * the resource's flags. All operations are managed and will be undone on
- * driver detach.
+ * Checks that a resource is a valid memory region, requests the memory
+ * region and ioremaps it. All operations are managed and will be undone
+ * on driver detach.
  *
  * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
  * on failure. Usage example:
@@ -153,11 +152,7 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
 		return IOMEM_ERR_PTR(-EBUSY);
 	}
 
-	if (res->flags & IORESOURCE_CACHEABLE)
-		dest_ptr = devm_ioremap(dev, res->start, size);
-	else
-		dest_ptr = devm_ioremap_nocache(dev, res->start, size);
-
+	dest_ptr = devm_ioremap(dev, res->start, size);
 	if (!dest_ptr) {
 		dev_err(dev, "ioremap failed for resource %pR\n", res);
 		devm_release_mem_region(dev, res->start, size);