From: Philip Prindeville <philipp@xxxxxxxxxxxxxxxxxxxxx>
Add support for finding the end-boundary of an E820 region given an
address falling in one such region. This is precursory functionality
for Coreboot loader support.
Signed-off-by: Philip Prindeville <philipp@xxxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Ed Wildgoose <ed@xxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andres Salomon <dilinger@xxxxxxxxxx>
Cc: Nathan Williams <nathan@xxxxxxxxxxxxxxx>
Cc: Guy Ellis <guy@xxxxxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Patrick Georgi <patrick.georgi@xxxxxxxxxxx>
Cc: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@xxxxxxx>
Cc: linux-geode@xxxxxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
---
include/linux/ioport.h | 1 +
kernel/resource.c | 29 +++++++++++++++++++++++++++++
2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 9d57a71..962d5a5 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -223,6 +223,7 @@ extern struct resource * __devm_request_region(struct device *dev,
extern void __devm_release_region(struct device *dev, struct resource *parent,
resource_size_t start, resource_size_t n);
extern int iomem_map_sanity_check(resource_size_t addr, unsigned long size);
+extern resource_size_t iomem_map_find_boundary(resource_size_t addr, int *mapped);
extern int iomem_is_exclusive(u64 addr);
extern int
diff --git a/kernel/resource.c b/kernel/resource.c
index 7640b3a..58e4fce 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1057,6 +1057,35 @@ static int __init reserve_setup(char *str)
__setup("reserve=", reserve_setup);
/*
+ * Find the upper boundary for the region that this address falls in, and
+ * whether it's currently mapped or not.
+ */
+
+resource_size_t iomem_map_find_boundary(resource_size_t addr, int *mapped)
+{
+ struct resource *p = &iomem_resource;
+ resource_size_t upper = 0;
+ loff_t l;
+
+ read_lock(&resource_lock);
+ for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ if (p->start > addr)
+ continue;
+ if (p->end < addr)
+ continue;
+ upper = p->end;
+ *mapped = ((p->flags & IORESOURCE_BUSY) != 0);
+ break;
+ }
+ read_unlock(&resource_lock);
+
+ return upper;
+}
+
+EXPORT_SYMBOL(iomem_map_find_boundary);
+
+
+/*
* Check if the requested addr and size spans more than any slot in the
* iomem resource tree.
*/
--
1.7.7.4
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