linux-kernel - [RFC] m68k: Set up dma mask for platform devices

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Date:   Sun, 13 May 2018 11:00:50 +1000
From:   Finn Thain <fthain@...egraphics.com.au>
To:     linux-m68k@...ts.linux-m68k.org, linux-kernel@...r.kernel.org
Cc:     Christoph Hellwig <hch@....de>
Subject: [RFC] m68k: Set up dma mask for platform devices

This avoids a WARNING splat when loading the macsonic or macmace driver.
Please see commit 205e1b7f51e4 ("dma-mapping: warn when there is no
coherent_dma_mask").

This implementation of arch_setup_pdev_archdata() differs from the one
in arch/powerpc in that this one avoids clobbering an existing dma mask.
For example, this approach preserves the mask set by the initializer for
struct platform_device mcf_fec0.

Note that either approach would make that initializer redundant and
commit f61e64310b75 ("m68k: set dma and coherent masks for platform
FEC ethernets") could be reverted.
---
 arch/m68k/kernel/dma.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index c01b9b8f97bf..463572c4943f 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -9,6 +9,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
+#include <linux/platform_device.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
@@ -165,3 +166,12 @@ const struct dma_map_ops m68k_dma_ops = {
 	.sync_sg_for_device	= m68k_dma_sync_sg_for_device,
 };
 EXPORT_SYMBOL(m68k_dma_ops);
+
+void arch_setup_pdev_archdata(struct platform_device *pdev)
+{
+	if (pdev->dev.coherent_dma_mask == DMA_MASK_NONE &&
+	    pdev->dev.dma_mask == NULL) {
+		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+	}
+}
-- 
2.16.1