[PATCH v6 01/16] initrd: Add weakly-linked generic free_initrd_mem.

[Shea Levy]

This function is effectively identical across 14 architectures, and
the generic implementation is small enough to be negligible in the
architectures that do override it. Many of the remaining divergent
implementations can be included in the common code path in future,
further reducing code duplication and sharing improvements between
architectures.

Series boot-tested on RISC-V (which now uses the generic
implementation) and x86_64 (which doesn't).

v6: Add information about build/run testing.
v5: Add more complete commit messages.
v4: Use weak symbols instead of Kconfig.
v3: Make the generic path opt-out instead of opt-in.
v2: Mark generic free_initrd_mem __init.

Signed-off-by: Shea Levy <shea at shealevy.com>
---
 init/initramfs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/init/initramfs.c b/init/initramfs.c
index 7e99a0038942..c8fe150f958a 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -526,6 +526,11 @@ extern unsigned long __initramfs_size;
 #include <linux/initrd.h>
 #include <linux/kexec.h>
 
+void __init __weak free_initrd_mem(unsigned long start, unsigned long end)
+{
+       free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+
 static void __init free_initrd(void)
 {
 #ifdef CONFIG_KEXEC_CORE
-- 
2.16.2