[PATCH v4 1/2] gpu: host1x: Set DMA mask

From: Alexandre Courbot
Date: Fri Feb 26 2016 - 04:07:35 EST


The default DMA mask covers a 32 bits address range, but host1x devices
can address a larger range on TK1 and TX1. Set the DMA mask to the range
addressable when we use the IOMMU to prevent the use of bounce buffers.

Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
---
Change since v3:
- Use the IOMMU-addressable range (when IOMMU is available) for each host1x
variation. This ensures that we can cover all physical memory while remaining
conservative if IOMMU is not used.
- Set the DMA range on the host1x device itself so all its childs inherit from it

drivers/gpu/host1x/dev.c | 7 +++++++
drivers/gpu/host1x/dev.h | 1 +
2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index 314bf3718cc7..ff348690df94 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -23,6 +23,7 @@
#include <linux/of_device.h>
#include <linux/clk.h>
#include <linux/io.h>
+#include <linux/dma-mapping.h>

#define CREATE_TRACE_POINTS
#include <trace/events/host1x.h>
@@ -68,6 +69,7 @@ static const struct host1x_info host1x01_info = {
.nb_bases = 8,
.init = host1x01_init,
.sync_offset = 0x3000,
+ .dma_mask = DMA_BIT_MASK(32),
};

static const struct host1x_info host1x02_info = {
@@ -77,6 +79,7 @@ static const struct host1x_info host1x02_info = {
.nb_bases = 12,
.init = host1x02_init,
.sync_offset = 0x3000,
+ .dma_mask = DMA_BIT_MASK(32),
};

static const struct host1x_info host1x04_info = {
@@ -86,6 +89,7 @@ static const struct host1x_info host1x04_info = {
.nb_bases = 64,
.init = host1x04_init,
.sync_offset = 0x2100,
+ .dma_mask = DMA_BIT_MASK(34),
};

static const struct host1x_info host1x05_info = {
@@ -95,6 +99,7 @@ static const struct host1x_info host1x05_info = {
.nb_bases = 64,
.init = host1x05_init,
.sync_offset = 0x2100,
+ .dma_mask = DMA_BIT_MASK(34),
};

static struct of_device_id host1x_of_match[] = {
@@ -148,6 +153,8 @@ static int host1x_probe(struct platform_device *pdev)
if (IS_ERR(host->regs))
return PTR_ERR(host->regs);

+ dma_set_mask_and_coherent(host->dev, host->info->dma_mask);
+
if (host->info->init) {
err = host->info->init(host);
if (err)
diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
index 0b6e8e9629c5..dace124994bb 100644
--- a/drivers/gpu/host1x/dev.h
+++ b/drivers/gpu/host1x/dev.h
@@ -96,6 +96,7 @@ struct host1x_info {
int nb_mlocks; /* host1x: number of mlocks */
int (*init)(struct host1x *); /* initialize per SoC ops */
int sync_offset;
+ u64 dma_mask; /* mask of addressable memory */
};

struct host1x {
--
2.7.1