[3.16.y-ckt stable] Patch "drivers: of: of_reserved_mem: fixup the alignment with CMA setup" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    drivers: of: of_reserved_mem: fixup the alignment with CMA setup

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt21.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4873b81137a65d828fce05b67110a4f34867e52b Mon Sep 17 00:00:00 2001
From: Jason Liu <r64343 at freescale.com>
Date: Tue, 10 Nov 2015 20:30:26 +0800
Subject: drivers: of: of_reserved_mem: fixup the alignment with CMA setup

commit 1cc8e3458b5110253c8f5aaf1890d5ffea9bb7b7 upstream.

There is an alignment mismatch issue between the of_reserved_mem and
the CMA setup requirement. The of_reserved_mem will try to get the
alignment value from the DTS and pass it to __memblock_alloc_base to
do the memory block base allocation, but the alignment value specified
in the DTS may not satisfy the CAM setup requirement since CMA setup
required the alignment as the following in the code:

align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);

The sanity check in the function of rmem_cma_setup will fail if the
alignment does not setup correctly and thus CMA will fail to setup.

This patch is to fixup the alignment to meet the CMA setup required.

Mailing-list-thread: https://lkml.org/lkml/2015/11/9/138
Signed-off-by: Jason Liu <r64343 at freescale.com>
Acked-by: Marek Szyprowski <m.szyprowski at samsung.com>
Cc: Grant Likely <grant.likely at linaro.org>
Cc: Rob Herring <robh+dt at kernel.org>
Signed-off-by: Rob Herring <robh at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/of/of_reserved_mem.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 632aae861375..86f284f0960e 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -123,6 +123,10 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
 		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 	}

+	/* Need adjust the alignment to satisfy the CMA requirement */
+	if (IS_ENABLED(CONFIG_CMA) && of_flat_dt_is_compatible(node, "shared-dma-pool"))
+		align = max(align, (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
+
 	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 	if (prop) {