Patch "MIPS: dma-default: Fix 32-bit fall back to GFP_DMA" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    MIPS: dma-default: Fix 32-bit fall back to GFP_DMA

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mips-dma-default-fix-32-bit-fall-back-to-gfp_dma.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 53960059d56ecef67d4ddd546731623641a3d2d1 Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 27 Mar 2015 08:33:43 +0000
Subject: MIPS: dma-default: Fix 32-bit fall back to GFP_DMA

From: James Hogan <james.hogan@imgtec.com>

commit 53960059d56ecef67d4ddd546731623641a3d2d1 upstream.

If there is a DMA zone (usually 24bit = 16MB I believe), but no DMA32
zone, as is the case for some 32-bit kernels, then massage_gfp_flags()
will cause DMA memory allocated for devices with a 32..63-bit
coherent_dma_mask to fall back to using __GFP_DMA, even though there may
only be 32-bits of physical address available anyway.

Correct that case to compare against a mask the size of phys_addr_t
instead of always using a 64-bit mask.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Fixes: a2e715a86c6d ("MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.")
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9610/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/mm/dma-default.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -100,7 +100,7 @@ static gfp_t massage_gfp_flags(const str
 	else
 #endif
 #if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
-	     if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+	     if (dev->coherent_dma_mask < DMA_BIT_MASK(sizeof(phys_addr_t) * 8))
 		dma_flag = __GFP_DMA;
 	else
 #endif


Patches currently in stable-queue which might be from james.hogan@imgtec.com are

queue-4.1/mips-dma-default-fix-32-bit-fall-back-to-gfp_dma.patch