@@ -278,6 +278,9 @@ extern int
walk_system_ram_res(u64 start, u64 end, void *arg,
int (*func)(struct resource *, void *));
extern int
+walk_system_ram_res_rev(u64 start, u64 end, void *arg,
+ int (*func)(struct resource *, void *));
+extern int
walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end,
void *arg, int (*func)(struct resource *, void *));
@@ -23,6 +23,8 @@
#include <linux/pfn.h>
#include <linux/mm.h>
#include <linux/resource_ext.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
#include <asm/io.h>
@@ -475,6 +477,44 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
}
/*
+ * This function, being a variant of walk_system_ram_res(), calls the @func
+ * callback against all memory ranges of type System RAM which are marked as
+ * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from
+ * higher to lower.
+ */
+int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
+ int (*func)(struct resource *, void *))
+{
+ unsigned long flags;
+ struct resource *res;
+ int ret = -1;
+
+ flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+ read_lock(&resource_lock);
+ list_for_each_entry_reverse(res, &iomem_resource.child, sibling) {
+ if (start >= end)
+ break;
+ if ((res->flags & flags) != flags)
+ continue;
+ if (res->desc != IORES_DESC_NONE)
+ continue;
+ if (res->end < start)
+ break;
+
+ if ((res->end >= start) && (res->start < end)) {
+ ret = (*func)(res, arg);
+ if (ret)
+ break;
+ }
+ end = res->start - 1;
+
+ }
+ read_unlock(&resource_lock);
+ return ret;
+}
+
+/*
* This function calls the @func callback against all memory ranges, which
* are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
*/
This function, being a variant of walk_system_ram_res() introduced in commit 8c86e70acead ("resource: provide new functions to walk through resources"), walks through a list of all the resources of System RAM in reversed order, i.e., from higher to lower. It will be used in kexec_file code. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Wei Yang <richard.weiyang@gmail.com> --- include/linux/ioport.h | 3 +++ kernel/resource.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+)