Catalin Marinas <[email protected]> writes:
> On Mon, Sep 21, 2026 at 08:18:40PM +0530, Aneesh Kumar K.V (Arm) wrote:
>> @@ -125,7 +126,8 @@ static inline int
>> dma_contiguous_reserve_area(phys_addr_t size,
>> return -ENOSYS;
>> }
>> static inline struct page *dma_alloc_from_contiguous(struct device *dev,
>> - size_t count, unsigned int order, bool no_warn)
>> + size_t count, unsigned int order, unsigned int required_order,
>> + bool no_warn)
>> {
>> return NULL;
>> }
>> @@ -136,7 +138,7 @@ static inline bool dma_release_from_contiguous(struct
>> device *dev,
>> }
>> /* Use fallback alloc() and free() when CONFIG_DMA_CMA=n */
>> static inline struct page *dma_alloc_contiguous(struct device *dev, size_t
>> size,
>> - gfp_t gfp)
>> + gfp_t gfp, unsigned int align_order)
>
> Can we not just bake the alignment further down in these functions
> rather than getting the callers to pass the {required,align}_order?
>
But, we need this to be conditional on CoCo shared allocations. We could
derive that from attrs and pass attrs instead of align_order, i.e.
something like:
struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
- unsigned int align, unsigned int required_align, bool no_warn)
+ unsigned int align, unsigned long attrs, bool no_warn)
{
- if (required_align > CONFIG_CMA_ALIGNMENT)
+ if (!dma_contiguous_resolve_alignment(attrs, &align))
return NULL;
- align = min(max(align, required_align), CONFIG_CMA_ALIGNMENT);
return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
}
with
+static bool dma_contiguous_resolve_alignment(unsigned long attrs,
+ unsigned int *align)
+{
+ unsigned int required_align = 0;
+
+ if (attrs & __DMA_ATTR_ALLOC_CC_SHARED)
+ required_align = get_order(cc_shared_granule_size());
+ if (required_align > CONFIG_CMA_ALIGNMENT)
+ return false;
+
+ *align = min(max(*align, required_align), CONFIG_CMA_ALIGNMENT);
+ return true;
+}
+
-aneesh
