14  * struct iova_bitmap_map - A bitmap representing an IOVA range
20  * total IOVA range. The struct iova_bitmap_map, though, represents the
21  * subset of said IOVA space that is pinned by its parent structure (struct
26  * records the IOVA *range* in the bitmap by setting the corresponding
29  * The bitmap is an array of u64 whereas each bit represents an IOVA of
32  *   data[(iova / page_size) / 64] & (1ULL << (iova % 64))
35 	/* base IOVA representing bit 0 of the first page */
36 	unsigned long iova;  member
52  * struct iova_bitmap - The IOVA bitmap object
56  * Abstracts the pinning work and iterates in IOVA ranges.
66  * For example iterating on a total IOVA range of 4G..128G, it will walk
72  * An example of the APIs on how to use/iterate over the IOVA bitmap:
74  *   bitmap = iova_bitmap_alloc(iova, length, page_size, data);
82  * Each iteration of the @dirty_reporter_fn is called with a unique @iova
87  *   iova_bitmap_set(bitmap, iova, iova_length);
94  * The IOVA bitmap is usually located on what tracks DMA mapped ranges or
95  * some form of IOVA range tracking that co-relates to the user passed
99 	/* IOVA range representing the currently mapped bitmap data */
111 	/* base IOVA of the whole bitmap */
112 	unsigned long iova;  member
114 	/* length of the IOVA range for the whole bitmap */
119  * Converts a relative IOVA to a bitmap index.
121  * for a given IOVA offset.
122  * Relative IOVA means relative to the bitmap::mapped base IOVA
123  * (stored in mapped::iova). All computations in this file are done using
124  * relative IOVAs and thus avoid an extra subtraction against mapped::iova.
128 						 unsigned long iova)  in iova_bitmap_offset_to_index()
132 	return iova / (BITS_PER_TYPE(*bitmap->bitmap) * pgsize);  in iova_bitmap_offset_to_index()
136  * Converts a bitmap index to a *relative* IOVA.
147  * Returns the base IOVA of the mapped range.
153 	return bitmap->iova + iova_bitmap_index_to_offset(bitmap, skip);  in iova_bitmap_mapped_iova()
158  * This is internal to IOVA bitmap and called when advancing the
197 	/* Base IOVA where @pages point to i.e. bit 0 of the first page */  in iova_bitmap_get()
198 	mapped->iova = iova_bitmap_mapped_iova(bitmap);  in iova_bitmap_get()
225  * iova_bitmap_alloc() - Allocates an IOVA bitmap object
226  * @iova: Start address of the IOVA range
227  * @length: Length of the IOVA range
228  * @page_size: Page size of the IOVA bitmap. It defines what each bit
232  * Allocates an IOVA object and initializes all its fields including the
238 struct iova_bitmap *iova_bitmap_alloc(unsigned long iova, size_t length,  in iova_bitmap_alloc()  argument
254 	bitmap->iova = iova;  in iova_bitmap_alloc()
256 	mapped->iova = iova;  in iova_bitmap_alloc()
274  * iova_bitmap_free() - Frees an IOVA bitmap object
275  * @bitmap: IOVA bitmap to free
312  * Returns the length of the mapped IOVA range.
316 	unsigned long max_iova = bitmap->iova + bitmap->length - 1;  in iova_bitmap_mapped_length()
317 	unsigned long iova = iova_bitmap_mapped_iova(bitmap);  in iova_bitmap_mapped_length()  local
322 	 * when converted to IOVA gives us a max length that the bitmap  in iova_bitmap_mapped_length()
324 	 * only cover the IOVA range in @bitmap::iova .. @bitmap::length.  in iova_bitmap_mapped_length()
329 	if (iova + remaining - 1 > max_iova)  in iova_bitmap_mapped_length()
330 		remaining -= ((iova + remaining - 1) - max_iova);  in iova_bitmap_mapped_length()
350 	unsigned long iova = iova_bitmap_mapped_length(bitmap) - 1;  in iova_bitmap_advance()  local
351 	unsigned long count = iova_bitmap_offset_to_index(bitmap, iova) + 1;  in iova_bitmap_advance()
365  * @bitmap: IOVA bitmap to iterate
367  * @fn: Function that gets called for each IOVA range
369  * Helper function to iterate over bitmap data representing a portion of IOVA
371  * mapped bitmap user pages into IOVA ranges to process.
393  * iova_bitmap_set() - Records an IOVA range in bitmap
394  * @bitmap: IOVA bitmap
395  * @iova: IOVA to start
396  * @length: IOVA range length
398  * Set the bits corresponding to the range [iova .. iova+length-1] in
403 		     unsigned long iova, size_t length)  in iova_bitmap_set()  argument
406 	unsigned long cur_bit = ((iova - mapped->iova) >>  in iova_bitmap_set()
408 	unsigned long last_bit = (((iova + length - 1) - mapped->iova) >>  in iova_bitmap_set()