[PATCH 02/02] clk: clk-of: Use alloc_bootmem() instead of kzalloc()

When of_clk_add_provider() is used at boot time (during .init_early on
ARM, in the motivating case for this patch), kzalloc() cannot be used
because slab isn't up yet.

Signed-off-by: Chris Ball <redacted>
---
 drivers/clk/clk-of.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-of.c b/drivers/clk/clk-of.c
index 8b43416..adbb56b 100644
--- a/drivers/clk/clk-of.c
+++ b/drivers/clk/clk-of.c

@@ -22,6 +22,7 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/bootmem.h>
 
 #ifdef CONFIG_OF
 

@@ -67,7 +68,7 @@ int of_clk_add_provider(struct device_node *np,
 {
 	struct of_clk_provider *cp;
 
-	cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
+	cp = alloc_bootmem(sizeof(struct of_clk_provider));
 	if (!cp)
 		return -ENOMEM;
 

-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child

On Thu, Jun 21, 2012 at 03:32:04AM -0400, Chris Ball wrote:

When of_clk_add_provider() is used at boot time (during .init_early on
ARM, in the motivating case for this patch), kzalloc() cannot be used
because slab isn't up yet.

Signed-off-by: Chris Ball <redacted>

I wouldn't use alloc_bootmem() unconditionally for this, as you have no
idea where other platforms may wire the call site up. slab is also
available a lot earlier now than it used to be, so many places that
required bootmem pages previously can get away with slab allocations now.

You could rework this as:

	if (slab_is_available())
		cp = kzalloc(...)
	else
		cp = alloc_bootmem(...)

and then it doesn't matter when and where it gets called.