diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_scatterlist.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_scatterlist.h | 118 |
1 files changed, 105 insertions, 13 deletions
diff --git a/drivers/gpu/drm/i915/i915_scatterlist.h b/drivers/gpu/drm/i915/i915_scatterlist.h index 5acca45ea981..6cf8a298849f 100644 --- a/drivers/gpu/drm/i915/i915_scatterlist.h +++ b/drivers/gpu/drm/i915/i915_scatterlist.h @@ -9,11 +9,13 @@ #include <linux/pfn.h> #include <linux/scatterlist.h> -#include <linux/swiotlb.h> +#include <linux/dma-mapping.h> +#include <xen/xen.h> #include "i915_gem.h" struct drm_mm_node; +struct ttm_resource; /* * Optimised SGL iterator for GEM objects @@ -89,6 +91,16 @@ static inline struct scatterlist *__sg_next(struct scatterlist *sg) ((__dp) = (__iter).dma + (__iter).curr), (__iter).sgp; \ (((__iter).curr += (__step)) >= (__iter).max) ? \ (__iter) = __sgt_iter(__sg_next((__iter).sgp), true), 0 : 0) +/** + * __for_each_daddr_next - iterates over the device addresses with pre-initialized iterator. + * @__dp: Device address (output) + * @__iter: 'struct sgt_iter' (iterator state, external) + * @__step: step size + */ +#define __for_each_daddr_next(__dp, __iter, __step) \ + for (; ((__dp) = (__iter).dma + (__iter).curr), (__iter).sgp; \ + (((__iter).curr += (__step)) >= (__iter).max) ? \ + (__iter) = __sgt_iter(__sg_next((__iter).sgp), true), 0 : 0) /** * for_each_sgt_page - iterate over the pages of the given sg_table @@ -126,23 +138,103 @@ static inline unsigned int i915_sg_dma_sizes(struct scatterlist *sg) return page_sizes; } -static inline unsigned int i915_sg_segment_size(void) +static inline unsigned int i915_sg_segment_size(struct device *dev) { - unsigned int size = swiotlb_max_segment(); + size_t max = min_t(size_t, UINT_MAX, dma_max_mapping_size(dev)); + + /* + * For Xen PV guests pages aren't contiguous in DMA (machine) address + * space. The DMA API takes care of that both in dma_alloc_* (by + * calling into the hypervisor to make the pages contiguous) and in + * dma_map_* (by bounce buffering). But i915 abuses ignores the + * coherency aspects of the DMA API and thus can't cope with bounce + * buffering actually happening, so add a hack here to force small + * allocations and mappings when running in PV mode on Xen. + * + * Note this will still break if bounce buffering is required for other + * reasons, like confidential computing hypervisors or PCIe root ports + * with addressing limitations. + */ + if (xen_pv_domain()) + max = PAGE_SIZE; + return round_down(max, PAGE_SIZE); +} + +bool i915_sg_trim(struct sg_table *orig_st); + +/** + * struct i915_refct_sgt_ops - Operations structure for struct i915_refct_sgt + */ +struct i915_refct_sgt_ops { + /** + * @release: Free the memory of the struct i915_refct_sgt + */ + void (*release)(struct kref *ref); +}; + +/** + * struct i915_refct_sgt - A refcounted scatter-gather table + * @kref: struct kref for refcounting + * @table: struct sg_table holding the scatter-gather table itself. Note that + * @table->sgl = NULL can be used to determine whether a scatter-gather table + * is present or not. + * @size: The size in bytes of the underlying memory buffer + * @ops: The operations structure. + */ +struct i915_refct_sgt { + struct kref kref; + struct sg_table table; + size_t size; + const struct i915_refct_sgt_ops *ops; +}; - if (size == 0) - size = UINT_MAX; +/** + * i915_refct_sgt_put - Put a refcounted sg-table + * @rsgt: the struct i915_refct_sgt to put. + */ +static inline void i915_refct_sgt_put(struct i915_refct_sgt *rsgt) +{ + if (rsgt) + kref_put(&rsgt->kref, rsgt->ops->release); +} - size = rounddown(size, PAGE_SIZE); - /* swiotlb_max_segment_size can return 1 byte when it means one page. */ - if (size < PAGE_SIZE) - size = PAGE_SIZE; +/** + * i915_refct_sgt_get - Get a refcounted sg-table + * @rsgt: the struct i915_refct_sgt to get. + */ +static inline struct i915_refct_sgt * +i915_refct_sgt_get(struct i915_refct_sgt *rsgt) +{ + kref_get(&rsgt->kref); + return rsgt; +} - return size; +/** + * __i915_refct_sgt_init - Initialize a refcounted sg-list with a custom + * operations structure + * @rsgt: The struct i915_refct_sgt to initialize. + * @size: Size in bytes of the underlying memory buffer. + * @ops: A customized operations structure in case the refcounted sg-list + * is embedded into another structure. + */ +static inline void __i915_refct_sgt_init(struct i915_refct_sgt *rsgt, + size_t size, + const struct i915_refct_sgt_ops *ops) +{ + kref_init(&rsgt->kref); + rsgt->table.sgl = NULL; + rsgt->size = size; + rsgt->ops = ops; } -bool i915_sg_trim(struct sg_table *orig_st); +void i915_refct_sgt_init(struct i915_refct_sgt *rsgt, size_t size); + +struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node, + u64 region_start, + u32 page_alignment); + +struct i915_refct_sgt *i915_rsgt_from_buddy_resource(struct ttm_resource *res, + u64 region_start, + u32 page_alignment); -struct sg_table *i915_sg_from_mm_node(const struct drm_mm_node *node, - u64 region_start); #endif |