1 files changed, 0 insertions, 423 deletions
diff --git a/drivers/vfio/iova_bitmap.c b/drivers/vfio/iova_bitmap.c
deleted file mode 100644
index 0848f920ef..0000000000
--- a/drivers/vfio/iova_bitmap.c
+++ /dev/null
@@ -1,423 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2022, Oracle and/or its affiliates.
- * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved
- */
-#include <linux/iova_bitmap.h>
-#include <linux/mm.h>
-#include <linux/slab.h>
-#include <linux/highmem.h>
-
-#define BITS_PER_PAGE (PAGE_SIZE * BITS_PER_BYTE)
-
-/*
- * struct iova_bitmap_map - A bitmap representing an IOVA range
- *
- * Main data structure for tracking mapped user pages of bitmap data.
- *
- * For example, for something recording dirty IOVAs, it will be provided a
- * struct iova_bitmap structure, as a general structure for iterating the
- * total IOVA range. The struct iova_bitmap_map, though, represents the
- * subset of said IOVA space that is pinned by its parent structure (struct
- * iova_bitmap).
- *
- * The user does not need to exact location of the bits in the bitmap.
- * From user perspective the only API available is iova_bitmap_set() which
- * records the IOVA *range* in the bitmap by setting the corresponding
- * bits.
- *
- * The bitmap is an array of u64 whereas each bit represents an IOVA of
- * range of (1 << pgshift). Thus formula for the bitmap data to be set is:
- *
- *   data[(iova / page_size) / 64] & (1ULL << (iova % 64))
- */
-struct iova_bitmap_map {
-	/* base IOVA representing bit 0 of the first page */
-	unsigned long iova;
-
-	/* page size order that each bit granules to */
-	unsigned long pgshift;
-
-	/* page offset of the first user page pinned */
-	unsigned long pgoff;
-
-	/* number of pages pinned */
-	unsigned long npages;
-
-	/* pinned pages representing the bitmap data */
-	struct page **pages;
-};
-
-/*
- * struct iova_bitmap - The IOVA bitmap object
- *
- * Main data structure for iterating over the bitmap data.
- *
- * Abstracts the pinning work and iterates in IOVA ranges.
- * It uses a windowing scheme and pins the bitmap in relatively
- * big ranges e.g.
- *
- * The bitmap object uses one base page to store all the pinned pages
- * pointers related to the bitmap. For sizeof(struct page*) == 8 it stores
- * 512 struct page pointers which, if the base page size is 4K, it means
- * 2M of bitmap data is pinned at a time. If the iova_bitmap page size is
- * also 4K then the range window to iterate is 64G.
- *
- * For example iterating on a total IOVA range of 4G..128G, it will walk
- * through this set of ranges:
- *
- *    4G  -  68G-1 (64G)
- *    68G - 128G-1 (64G)
- *
- * An example of the APIs on how to use/iterate over the IOVA bitmap:
- *
- *   bitmap = iova_bitmap_alloc(iova, length, page_size, data);
- *   if (IS_ERR(bitmap))
- *       return PTR_ERR(bitmap);
- *
- *   ret = iova_bitmap_for_each(bitmap, arg, dirty_reporter_fn);
- *
- *   iova_bitmap_free(bitmap);
- *
- * Each iteration of the @dirty_reporter_fn is called with a unique @iova
- * and @length argument, indicating the current range available through the
- * iova_bitmap. The @dirty_reporter_fn uses iova_bitmap_set() to mark dirty
- * areas (@iova_length) within that provided range, as following:
- *
- *   iova_bitmap_set(bitmap, iova, iova_length);
- *
- * The internals of the object uses an index @mapped_base_index that indexes
- * which u64 word of the bitmap is mapped, up to @mapped_total_index.
- * Those keep being incremented until @mapped_total_index is reached while
- * mapping up to PAGE_SIZE / sizeof(struct page*) maximum of pages.
- *
- * The IOVA bitmap is usually located on what tracks DMA mapped ranges or
- * some form of IOVA range tracking that co-relates to the user passed
- * bitmap.
- */
-struct iova_bitmap {
-	/* IOVA range representing the currently mapped bitmap data */
-	struct iova_bitmap_map mapped;
-
-	/* userspace address of the bitmap */
-	u64 __user *bitmap;
-
-	/* u64 index that @mapped points to */
-	unsigned long mapped_base_index;
-
-	/* how many u64 can we walk in total */
-	unsigned long mapped_total_index;
-
-	/* base IOVA of the whole bitmap */
-	unsigned long iova;
-
-	/* length of the IOVA range for the whole bitmap */
-	size_t length;
-};
-
-/*
- * Converts a relative IOVA to a bitmap index.
- * This function provides the index into the u64 array (bitmap::bitmap)
- * for a given IOVA offset.
- * Relative IOVA means relative to the bitmap::mapped base IOVA
- * (stored in mapped::iova). All computations in this file are done using
- * relative IOVAs and thus avoid an extra subtraction against mapped::iova.
- * The user API iova_bitmap_set() always uses a regular absolute IOVAs.
- */
-static unsigned long iova_bitmap_offset_to_index(struct iova_bitmap *bitmap,
-						 unsigned long iova)
-{
-	unsigned long pgsize = 1 << bitmap->mapped.pgshift;
-
-	return iova / (BITS_PER_TYPE(*bitmap->bitmap) * pgsize);
-}
-
-/*
- * Converts a bitmap index to a *relative* IOVA.
- */
-static unsigned long iova_bitmap_index_to_offset(struct iova_bitmap *bitmap,
-						 unsigned long index)
-{
-	unsigned long pgshift = bitmap->mapped.pgshift;
-
-	return (index * BITS_PER_TYPE(*bitmap->bitmap)) << pgshift;
-}
-
-/*
- * Returns the base IOVA of the mapped range.
- */
-static unsigned long iova_bitmap_mapped_iova(struct iova_bitmap *bitmap)
-{
-	unsigned long skip = bitmap->mapped_base_index;
-
-	return bitmap->iova + iova_bitmap_index_to_offset(bitmap, skip);
-}
-
-/*
- * Pins the bitmap user pages for the current range window.
- * This is internal to IOVA bitmap and called when advancing the
- * index (@mapped_base_index) or allocating the bitmap.
- */
-static int iova_bitmap_get(struct iova_bitmap *bitmap)
-{
-	struct iova_bitmap_map *mapped = &bitmap->mapped;
-	unsigned long npages;
-	u64 __user *addr;
-	long ret;
-
-	/*
-	 * @mapped_base_index is the index of the currently mapped u64 words
-	 * that we have access. Anything before @mapped_base_index is not
-	 * mapped. The range @mapped_base_index .. @mapped_total_index-1 is
-	 * mapped but capped at a maximum number of pages.
-	 */
-	npages = DIV_ROUND_UP((bitmap->mapped_total_index -
-			       bitmap->mapped_base_index) *
-			       sizeof(*bitmap->bitmap), PAGE_SIZE);
-
-	/*
-	 * We always cap at max number of 'struct page' a base page can fit.
-	 * This is, for example, on x86 means 2M of bitmap data max.
-	 */
-	npages = min(npages,  PAGE_SIZE / sizeof(struct page *));
-
-	/*
-	 * Bitmap address to be pinned is calculated via pointer arithmetic
-	 * with bitmap u64 word index.
-	 */
-	addr = bitmap->bitmap + bitmap->mapped_base_index;
-
-	ret = pin_user_pages_fast((unsigned long)addr, npages,
-				  FOLL_WRITE, mapped->pages);
-	if (ret <= 0)
-		return -EFAULT;
-
-	mapped->npages = (unsigned long)ret;
-	/* Base IOVA where @pages point to i.e. bit 0 of the first page */
-	mapped->iova = iova_bitmap_mapped_iova(bitmap);
-
-	/*
-	 * offset of the page where pinned pages bit 0 is located.
-	 * This handles the case where the bitmap is not PAGE_SIZE
-	 * aligned.
-	 */
-	mapped->pgoff = offset_in_page(addr);
-	return 0;
-}
-
-/*
- * Unpins the bitmap user pages and clears @npages
- * (un)pinning is abstracted from API user and it's done when advancing
- * the index or freeing the bitmap.
- */
-static void iova_bitmap_put(struct iova_bitmap *bitmap)
-{
-	struct iova_bitmap_map *mapped = &bitmap->mapped;
-
-	if (mapped->npages) {
-		unpin_user_pages(mapped->pages, mapped->npages);
-		mapped->npages = 0;
-	}
-}
-
-/**
- * iova_bitmap_alloc() - Allocates an IOVA bitmap object
- * @iova: Start address of the IOVA range
- * @length: Length of the IOVA range
- * @page_size: Page size of the IOVA bitmap. It defines what each bit
- *             granularity represents
- * @data: Userspace address of the bitmap
- *
- * Allocates an IOVA object and initializes all its fields including the
- * first user pages of @data.
- *
- * Return: A pointer to a newly allocated struct iova_bitmap
- * or ERR_PTR() on error.
- */
-struct iova_bitmap *iova_bitmap_alloc(unsigned long iova, size_t length,
-				      unsigned long page_size, u64 __user *data)
-{
-	struct iova_bitmap_map *mapped;
-	struct iova_bitmap *bitmap;
-	int rc;
-
-	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
-	if (!bitmap)
-		return ERR_PTR(-ENOMEM);
-
-	mapped = &bitmap->mapped;
-	mapped->pgshift = __ffs(page_size);
-	bitmap->bitmap = data;
-	bitmap->mapped_total_index =
-		iova_bitmap_offset_to_index(bitmap, length - 1) + 1;
-	bitmap->iova = iova;
-	bitmap->length = length;
-	mapped->iova = iova;
-	mapped->pages = (struct page **)__get_free_page(GFP_KERNEL);
-	if (!mapped->pages) {
-		rc = -ENOMEM;
-		goto err;
-	}
-
-	rc = iova_bitmap_get(bitmap);
-	if (rc)
-		goto err;
-	return bitmap;
-
-err:
-	iova_bitmap_free(bitmap);
-	return ERR_PTR(rc);
-}
-
-/**
- * iova_bitmap_free() - Frees an IOVA bitmap object
- * @bitmap: IOVA bitmap to free
- *
- * It unpins and releases pages array memory and clears any leftover
- * state.
- */
-void iova_bitmap_free(struct iova_bitmap *bitmap)
-{
-	struct iova_bitmap_map *mapped = &bitmap->mapped;
-
-	iova_bitmap_put(bitmap);
-
-	if (mapped->pages) {
-		free_page((unsigned long)mapped->pages);
-		mapped->pages = NULL;
-	}
-
-	kfree(bitmap);
-}
-
-/*
- * Returns the remaining bitmap indexes from mapped_total_index to process for
- * the currently pinned bitmap pages.
- */
-static unsigned long iova_bitmap_mapped_remaining(struct iova_bitmap *bitmap)
-{
-	unsigned long remaining, bytes;
-
-	bytes = (bitmap->mapped.npages << PAGE_SHIFT) - bitmap->mapped.pgoff;
-
-	remaining = bitmap->mapped_total_index - bitmap->mapped_base_index;
-	remaining = min_t(unsigned long, remaining,
-			  bytes / sizeof(*bitmap->bitmap));
-
-	return remaining;
-}
-
-/*
- * Returns the length of the mapped IOVA range.
- */
-static unsigned long iova_bitmap_mapped_length(struct iova_bitmap *bitmap)
-{
-	unsigned long max_iova = bitmap->iova + bitmap->length - 1;
-	unsigned long iova = iova_bitmap_mapped_iova(bitmap);
-	unsigned long remaining;
-
-	/*
-	 * iova_bitmap_mapped_remaining() returns a number of indexes which
-	 * when converted to IOVA gives us a max length that the bitmap
-	 * pinned data can cover. Afterwards, that is capped to
-	 * only cover the IOVA range in @bitmap::iova .. @bitmap::length.
-	 */
-	remaining = iova_bitmap_index_to_offset(bitmap,
-			iova_bitmap_mapped_remaining(bitmap));
-
-	if (iova + remaining - 1 > max_iova)
-		remaining -= ((iova + remaining - 1) - max_iova);
-
-	return remaining;
-}
-
-/*
- * Returns true if there's not more data to iterate.
- */
-static bool iova_bitmap_done(struct iova_bitmap *bitmap)
-{
-	return bitmap->mapped_base_index >= bitmap->mapped_total_index;
-}
-
-/*
- * Advances to the next range, releases the current pinned
- * pages and pins the next set of bitmap pages.
- * Returns 0 on success or otherwise errno.
- */
-static int iova_bitmap_advance(struct iova_bitmap *bitmap)
-{
-	unsigned long iova = iova_bitmap_mapped_length(bitmap) - 1;
-	unsigned long count = iova_bitmap_offset_to_index(bitmap, iova) + 1;
-
-	bitmap->mapped_base_index += count;
-
-	iova_bitmap_put(bitmap);
-	if (iova_bitmap_done(bitmap))
-		return 0;
-
-	/* When advancing the index we pin the next set of bitmap pages */
-	return iova_bitmap_get(bitmap);
-}
-
-/**
- * iova_bitmap_for_each() - Iterates over the bitmap
- * @bitmap: IOVA bitmap to iterate
- * @opaque: Additional argument to pass to the callback
- * @fn: Function that gets called for each IOVA range
- *
- * Helper function to iterate over bitmap data representing a portion of IOVA
- * space. It hides the complexity of iterating bitmaps and translating the
- * mapped bitmap user pages into IOVA ranges to process.
- *
- * Return: 0 on success, and an error on failure either upon
- * iteration or when the callback returns an error.
- */
-int iova_bitmap_for_each(struct iova_bitmap *bitmap, void *opaque,
-			 iova_bitmap_fn_t fn)
-{
-	int ret = 0;
-
-	for (; !iova_bitmap_done(bitmap) && !ret;
-	     ret = iova_bitmap_advance(bitmap)) {
-		ret = fn(bitmap, iova_bitmap_mapped_iova(bitmap),
-			 iova_bitmap_mapped_length(bitmap), opaque);
-		if (ret)
-			break;
-	}
-
-	return ret;
-}
-
-/**
- * iova_bitmap_set() - Records an IOVA range in bitmap
- * @bitmap: IOVA bitmap
- * @iova: IOVA to start
- * @length: IOVA range length
- *
- * Set the bits corresponding to the range [iova .. iova+length-1] in
- * the user bitmap.
- *
- */
-void iova_bitmap_set(struct iova_bitmap *bitmap,
-		     unsigned long iova, size_t length)
-{
-	struct iova_bitmap_map *mapped = &bitmap->mapped;
-	unsigned long cur_bit = ((iova - mapped->iova) >>
-			mapped->pgshift) + mapped->pgoff * BITS_PER_BYTE;
-	unsigned long last_bit = (((iova + length - 1) - mapped->iova) >>
-			mapped->pgshift) + mapped->pgoff * BITS_PER_BYTE;
-
-	do {
-		unsigned int page_idx = cur_bit / BITS_PER_PAGE;
-		unsigned int offset = cur_bit % BITS_PER_PAGE;
-		unsigned int nbits = min(BITS_PER_PAGE - offset,
-					 last_bit - cur_bit + 1);
-		void *kaddr;
-
-		kaddr = kmap_local_page(mapped->pages[page_idx]);
-		bitmap_set(kaddr, offset, nbits);
-		kunmap_local(kaddr);
-		cur_bit += nbits;
-	} while (cur_bit <= last_bit);
-}
-EXPORT_SYMBOL_GPL(iova_bitmap_set);