staging: ion: remove from the tree

The ION android code has long been marked to be removed, now that we
dma-buf support merged into the real part of the kernel.

It was thought that we could wait to remove the ion kernel at a later
time, but as the out-of-tree Android fork of the ion code has diverged
quite a bit, and any Android device using the ion interface uses that
forked version and not this in-tree version, the in-tree copy of the
code is abandonded and not used by anyone.

Combine this abandoned codebase with the need to make changes to it in
order to keep the kernel building properly, which then causes merge
issues when merging those changes into the out-of-tree Android code, and
you end up with two different groups of people (the in-kernel-tree
developers, and the Android kernel developers) who are both annoyed at
the current situation.  Because of this problem, just drop the in-kernel
copy of the ion code now, as it's not used, and is only causing problems
for everyone involved.

Cc: "Arve Hjønnevåg" <arve@android.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Laura Abbott <laura@labbott.name>
Cc: Martijn Coenen <maco@android.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Todd Kjos <tkjos@android.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200827123627.538189-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 0 insertions, 286 deletions

diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
deleted file mode 100644
index ea7e0a244ffc..000000000000
--- a/drivers/staging/android/ion/ion_heap.c
+++ /dev/null
@@ -1,286 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * ION Memory Allocator generic heap helpers
- *
- * Copyright (C) 2011 Google, Inc.
- */
-
-#include <linux/err.h>
-#include <linux/freezer.h>
-#include <linux/kthread.h>
-#include <linux/mm.h>
-#include <linux/rtmutex.h>
-#include <linux/sched.h>
-#include <uapi/linux/sched/types.h>
-#include <linux/scatterlist.h>
-#include <linux/vmalloc.h>
-
-#include "ion.h"
-
-void *ion_heap_map_kernel(struct ion_heap *heap,
-			  struct ion_buffer *buffer)
-{
-	struct sg_page_iter piter;
-	void *vaddr;
-	pgprot_t pgprot;
-	struct sg_table *table = buffer->sg_table;
-	int npages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
-	struct page **pages = vmalloc(array_size(npages,
-						 sizeof(struct page *)));
-	struct page **tmp = pages;
-
-	if (!pages)
-		return ERR_PTR(-ENOMEM);
-
-	if (buffer->flags & ION_FLAG_CACHED)
-		pgprot = PAGE_KERNEL;
-	else
-		pgprot = pgprot_writecombine(PAGE_KERNEL);
-
-	for_each_sgtable_page(table, &piter, 0) {
-		BUG_ON(tmp - pages >= npages);
-		*tmp++ = sg_page_iter_page(&piter);
-	}
-
-	vaddr = vmap(pages, npages, VM_MAP, pgprot);
-	vfree(pages);
-
-	if (!vaddr)
-		return ERR_PTR(-ENOMEM);
-
-	return vaddr;
-}
-
-void ion_heap_unmap_kernel(struct ion_heap *heap,
-			   struct ion_buffer *buffer)
-{
-	vunmap(buffer->vaddr);
-}
-
-int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
-		      struct vm_area_struct *vma)
-{
-	struct sg_page_iter piter;
-	struct sg_table *table = buffer->sg_table;
-	unsigned long addr = vma->vm_start;
-	int ret;
-
-	for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
-		struct page *page = sg_page_iter_page(&piter);
-
-		ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE,
-				      vma->vm_page_prot);
-		if (ret)
-			return ret;
-		addr += PAGE_SIZE;
-		if (addr >= vma->vm_end)
-			return 0;
-	}
-
-	return 0;
-}
-
-static int ion_heap_clear_pages(struct page **pages, int num, pgprot_t pgprot)
-{
-	void *addr = vmap(pages, num, VM_MAP, pgprot);
-
-	if (!addr)
-		return -ENOMEM;
-	memset(addr, 0, PAGE_SIZE * num);
-	vunmap(addr);
-
-	return 0;
-}
-
-static int ion_heap_sglist_zero(struct sg_table *sgt, pgprot_t pgprot)
-{
-	int p = 0;
-	int ret = 0;
-	struct sg_page_iter piter;
-	struct page *pages[32];
-
-	for_each_sgtable_page(sgt, &piter, 0) {
-		pages[p++] = sg_page_iter_page(&piter);
-		if (p == ARRAY_SIZE(pages)) {
-			ret = ion_heap_clear_pages(pages, p, pgprot);
-			if (ret)
-				return ret;
-			p = 0;
-		}
-	}
-	if (p)
-		ret = ion_heap_clear_pages(pages, p, pgprot);
-
-	return ret;
-}
-
-int ion_heap_buffer_zero(struct ion_buffer *buffer)
-{
-	struct sg_table *table = buffer->sg_table;
-	pgprot_t pgprot;
-
-	if (buffer->flags & ION_FLAG_CACHED)
-		pgprot = PAGE_KERNEL;
-	else
-		pgprot = pgprot_writecombine(PAGE_KERNEL);
-
-	return ion_heap_sglist_zero(table, pgprot);
-}
-
-void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer)
-{
-	spin_lock(&heap->free_lock);
-	list_add(&buffer->list, &heap->free_list);
-	heap->free_list_size += buffer->size;
-	spin_unlock(&heap->free_lock);
-	wake_up(&heap->waitqueue);
-}
-
-size_t ion_heap_freelist_size(struct ion_heap *heap)
-{
-	size_t size;
-
-	spin_lock(&heap->free_lock);
-	size = heap->free_list_size;
-	spin_unlock(&heap->free_lock);
-
-	return size;
-}
-
-static size_t _ion_heap_freelist_drain(struct ion_heap *heap, size_t size,
-				       bool skip_pools)
-{
-	struct ion_buffer *buffer;
-	size_t total_drained = 0;
-
-	if (ion_heap_freelist_size(heap) == 0)
-		return 0;
-
-	spin_lock(&heap->free_lock);
-	if (size == 0)
-		size = heap->free_list_size;
-
-	while (!list_empty(&heap->free_list)) {
-		if (total_drained >= size)
-			break;
-		buffer = list_first_entry(&heap->free_list, struct ion_buffer,
-					  list);
-		list_del(&buffer->list);
-		heap->free_list_size -= buffer->size;
-		if (skip_pools)
-			buffer->private_flags |= ION_PRIV_FLAG_SHRINKER_FREE;
-		total_drained += buffer->size;
-		spin_unlock(&heap->free_lock);
-		ion_buffer_destroy(buffer);
-		spin_lock(&heap->free_lock);
-	}
-	spin_unlock(&heap->free_lock);
-
-	return total_drained;
-}
-
-size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size)
-{
-	return _ion_heap_freelist_drain(heap, size, false);
-}
-
-size_t ion_heap_freelist_shrink(struct ion_heap *heap, size_t size)
-{
-	return _ion_heap_freelist_drain(heap, size, true);
-}
-
-static int ion_heap_deferred_free(void *data)
-{
-	struct ion_heap *heap = data;
-
-	while (true) {
-		struct ion_buffer *buffer;
-
-		wait_event_freezable(heap->waitqueue,
-				     ion_heap_freelist_size(heap) > 0);
-
-		spin_lock(&heap->free_lock);
-		if (list_empty(&heap->free_list)) {
-			spin_unlock(&heap->free_lock);
-			continue;
-		}
-		buffer = list_first_entry(&heap->free_list, struct ion_buffer,
-					  list);
-		list_del(&buffer->list);
-		heap->free_list_size -= buffer->size;
-		spin_unlock(&heap->free_lock);
-		ion_buffer_destroy(buffer);
-	}
-
-	return 0;
-}
-
-int ion_heap_init_deferred_free(struct ion_heap *heap)
-{
-	INIT_LIST_HEAD(&heap->free_list);
-	init_waitqueue_head(&heap->waitqueue);
-	heap->task = kthread_run(ion_heap_deferred_free, heap,
-				 "%s", heap->name);
-	if (IS_ERR(heap->task)) {
-		pr_err("%s: creating thread for deferred free failed\n",
-		       __func__);
-		return PTR_ERR_OR_ZERO(heap->task);
-	}
-	sched_set_normal(heap->task, 19);
-
-	return 0;
-}
-
-static unsigned long ion_heap_shrink_count(struct shrinker *shrinker,
-					   struct shrink_control *sc)
-{
-	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
-					     shrinker);
-	int total = 0;
-
-	total = ion_heap_freelist_size(heap) / PAGE_SIZE;
-
-	if (heap->ops->shrink)
-		total += heap->ops->shrink(heap, sc->gfp_mask, 0);
-
-	return total;
-}
-
-static unsigned long ion_heap_shrink_scan(struct shrinker *shrinker,
-					  struct shrink_control *sc)
-{
-	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
-					     shrinker);
-	int freed = 0;
-	int to_scan = sc->nr_to_scan;
-
-	if (to_scan == 0)
-		return 0;
-
-	/*
-	 * shrink the free list first, no point in zeroing the memory if we're
-	 * just going to reclaim it. Also, skip any possible page pooling.
-	 */
-	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
-		freed = ion_heap_freelist_shrink(heap, to_scan * PAGE_SIZE) /
-				PAGE_SIZE;
-
-	to_scan -= freed;
-	if (to_scan <= 0)
-		return freed;
-
-	if (heap->ops->shrink)
-		freed += heap->ops->shrink(heap, sc->gfp_mask, to_scan);
-
-	return freed;
-}
-
-int ion_heap_init_shrinker(struct ion_heap *heap)
-{
-	heap->shrinker.count_objects = ion_heap_shrink_count;
-	heap->shrinker.scan_objects = ion_heap_shrink_scan;
-	heap->shrinker.seeks = DEFAULT_SEEKS;
-	heap->shrinker.batch = 0;
-
-	return register_shrinker(&heap->shrinker);
-}