This is somewhat modelled after the powerpc version, and differs from
the legacy fallback in use fls64 instead of pointlessly splitting up the
address into low and high dwords and in that it takes (__)phys_to_dma
into account.
Signed-off-by: Christoph Hellwig
Acked-by: Benjamin Herrenschmidt
On 27/09/18 16:28, Christoph Hellwig wrote:
On Thu, Sep 27, 2018 at 03:12:25PM +0100, Robin Murphy wrote:
+u64 dma_direct_get_required_mask(struct device *dev)
+{
+ u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT);
+
+ return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
On Thu, Sep 27, 2018 at 03:12:25PM +0100, Robin Murphy wrote:
>> +u64 dma_direct_get_required_mask(struct device *dev)
>> +{
>> +u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT);
>> +
>> +return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
>
> I think that may as well just use
On 20/09/18 19:52, Christoph Hellwig wrote:
This is somewhat modelled after the powerpc version, and differs from
the legacy fallback in use fls64 instead of pointlessly splitting up the
address into low and high dwords and in that it takes (__)phys_to_dma
into account.
Signed-off-by: Christoph
On Thu, 2018-09-20 at 20:52 +0200, Christoph Hellwig wrote:
> This is somewhat modelled after the powerpc version, and differs from
> the legacy fallback in use fls64 instead of pointlessly splitting up the
> address into low and high dwords and in that it takes (__)phys_to_dma
> into account.
This is somewhat modelled after the powerpc version, and differs from
the legacy fallback in use fls64 instead of pointlessly splitting up the
address into low and high dwords and in that it takes (__)phys_to_dma
into account.
Signed-off-by: Christoph Hellwig
---
include/linux/dma-direct.h | 1
