Most of the kernel assumes that PFN0 is the start of the physical
memory (RAM). This assumptions is not true on most of the ARM SOCs
and hence and if one try to update the ARM port to follow the assumptions,
we end of breaking the dma bounce limit for few block layer drivers.
One such example is trying to unify the meaning of max*_pfn on ARM
as the bootmem layer expects, breaks few block layer driver dma
bounce limit.

To fix this problem, we introduce dma_max_pfn(dev) generic helper with
a possibility of override from the architecture code. The helper converts
a DMA bitmask of bits to a block PFN number. In all the generic cases,
it is just  "dev->dma_mask >> PAGE_SHIFT" and hence default behavior
is maintained as is.

Subsequent patches will make use of the helper. No functional change.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The blk_queue_bounce_limit() API parameter 'dma_mask' is actually the
maximum address the device can handle rather than a dma_mask. Rename
it accordingly to avoid it being interpreted as dma_mask.

No functional change.

The idea is to fix the bad assumptions about dma_mask wherever it could
be miss-interpreted.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

We need to start treating DMA masks as something which is specific to
the bus that the device resides on, otherwise we're going to hit all
sorts of nasty issues with LPAE and 32-bit DMA controllers in >32-bit
systems, where memory is offset from PFN 0.

In order to start doing this, we convert the DMA mask to a PFN using
the device specific dma_to_pfn() macro.  This is the reverse of the
pfn_to_dma() macro which is used to get the DMA address for the device.

This gives us a PFN mask, which we can then check against the PFN
limit of the DMA zone.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The dma mask is not configured in the current code.
This was triggered by soc-dmaengine-pcm which allocate the dma
buffers with the imx-sdma as device.
This commit fix audio on imx31.
Signed-off-by: Philippe Rétornaz <philippe.retornaz@epfl.ch>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This driver doesn't need to directly access DMA masks if it uses the
platform_device_register_full() API rather than
platform_device_register_simple() - the former function can initialize
the DMA mask appropriately.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

dcdbas was explicitly initializing DMA masks thusly:
	dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
	dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
which bypasses the architecture check.  Moreover, it is creating the
dcdbas_pdev device itself, and using the platform_device_register_full()
avoids some of this explicit initialization.

Convert the driver to use platform_device_register_full(), and as it
makes use of coherent DMA, also call dma_set_coherent_mask() to ensure
that the architecture gets to check the mask.
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

register_platform_device_full() can setup the DMA mask provided the
appropriate member is set in struct platform_device_info.  So lets
make that be the case.  This avoids a direct reference to the DMA
masks by this driver.

While here, add the dma_set_mask_and_coherent() call which the DMA API
requires DMA-using drivers to call.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Use platform_device_register_full() for those drivers which can, to
avoid messing directly with DMA masks.  This can only be done when
the driver does not need to access the allocated musb platform device
from within its callbacks, which may be called during the musb
device probing.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Don't statically allocate struct device's in modules, and shut the
warning up with an empty release() function.  There's a reason that
warning is there and that's not for people to hide in this way.  It's
there to persuade people to use the correct APIs to allocate platform
devices.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The correct way for a driver to specify the coherent DMA mask is
not to directly access the field in the struct device, but to use
dma_set_coherent_mask().  Only arch and bus code should access this
member directly.

Convert all direct write accesses to using the correct API.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The correct way for a driver to specify the coherent DMA mask is
not to directly access the field in the struct device, but to use
dma_set_coherent_mask().  Only arch and bus code should access this
member directly.

Convert all direct write accesses to using the correct API.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The correct way for a driver to specify the coherent DMA mask is
not to directly access the field in the struct device, but to use
dma_set_coherent_mask().  Only arch and bus code should access this
member directly.

Convert all direct write accesses to using the correct API.
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The code sequence:
	dev->coherent_dma_mask = DMA_BIT_MASK(24);
	dev->dma_mask = &dev->coherent_dma_mask;
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The code sequence:
	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The code sequence:
	pldat->pdev->dev.coherent_dma_mask = 0xFFFFFFFF;
	pldat->pdev->dev.dma_mask = &pldat->pdev->dev.coherent_dma_mask;
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The code sequence:
	dev->dma_mask = &dev->coherent_dma_mask;
	dev->coherent_dma_mask = dma_mask;
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The code sequence:
	isp->raw_dmamask = DMA_BIT_MASK(32);
	isp->dev->dma_mask = &isp->raw_dmamask;
	isp->dev->coherent_dma_mask = DMA_BIT_MASK(32);
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This code sequence:
	if (!pdev->dev.dma_mask) {
		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
	}
bypasses the architectures check on the DMA mask.  It can be replaced
with dma_coerce_mask_and_coherent(), avoiding the direct initialization
of this mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Convert this code sequence:
	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
to use dma_coerce_mask_and_coherent() to avoid bypassing the architecture
check on the DMA mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This code sequence is unsafe in modules:

static u64 mask = DMA_BIT_MASK(something);
...
	if (!dev->dma_mask)
		dev->dma_mask = &mask;

as if a module is reloaded, the mask will be pointing at the original
module's mask address, and this can lead to oopses.  Moreover, they
all follow this with:

	if (!dev->coherent_dma_mask)
		dev->coherent_dma_mask = mask;

where 'mask' is the same value as the statically defined mask, and this
bypasses the architecture's check on whether the DMA mask is possible.

Fix these issues by using the new dma_coerce_coherent_and_mask()
function.
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Many drivers contain code such as:

	dev->dma_mask = &dev->coherent_dma_mask;
	dev->coherent_dma_mask = MASK;

Let's move this pattern out of drivers and have the DMA API provide a
helper for it.  This helper uses dma_set_mask_and_coherent() to allow
platform issues to be properly dealt with via dma_set_mask()/
dma_is_supported().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Add a comment to explain why this driver doesn't call any of the DMA
API dma_set_mask() functions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The DMA API requires drivers to call the appropriate dma_set_mask()
functions before doing any DMA mapping.  Add this required call to
the AMBA PL08x driver.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The DMA API requires drivers to call the appropriate dma_set_mask()
functions before doing any DMA mapping.  Add this required call to
the AMBA PL330 driver.
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The DMA API requires drivers to call the appropriate dma_set_mask()
functions before doing any DMA mapping.  Add this required call to
the AMBA PL08x driver.
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

AMBA Primecell devices always treat streaming and coherent DMA exactly
the same, so there's no point in having the masks separated.
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Replace the following sequence:

	dma_set_mask(dev, mask);
	dma_set_coherent_mask(dev, mask);

with a call to the new helper dma_set_mask_and_coherent().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>