[PATCH 4.16 146/272] zorro: Set up z->dev.dma_mask for the DMA API

Greg Kroah-Hartman
2018-05-28T11:47:20Z

From: Michael Schmitz <schmitzmic@gmail.com>

[ Upstream commit 55496d3fe2acd1a365c43cbd613a20ecd4d74395 ]

The generic DMA API uses dev->dma_mask to check the DMA addressable
memory bitmask, and warns if no mask is set or even allocated.

Set z->dev.dma_coherent_mask on Zorro bus scan, and make z->dev.dma_mask
to point to z->dev.dma_coherent_mask so device drivers that need DMA have
everything set up to avoid warnings from dma_alloc_coherent(). Drivers can
still use dma_set_mask_and_coherent() to explicitly set their DMA bit mask.

Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
[geert: Handle Zorro II with 24-bit address space]
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/zorro/zorro.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- a/drivers/zorro/zorro.c
+++ b/drivers/zorro/zorro.c
@@ -16,6 +16,7 @@
#include <linux/bitops.h>
#include <linux/string.h>
#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
#include <linux/slab.h>

#include <asm/byteorder.h>
@@ -185,6 +186,17 @@ static int __init amiga_zorro_probe(stru
z->dev.parent = &bus->dev;
z->dev.bus = &zorro_bus_type;
z->dev.id = i;
+ switch (z->rom.er_Type & ERT_TYPEMASK) {
+ case ERT_ZORROIII:
+ z->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+ break;
+
+ case ERT_ZORROII:
+ default:
+ z->dev.coherent_dma_mask = DMA_BIT_MASK(24);
+ break;
+ }
+ z->dev.dma_mask = &z->dev.coherent_dma_mask;
}

/* ... then register them */