BACKPORT: FROMGIT: binder: rename lru shrinker utilities

Now that the page allocation step is done separately we should rename
the binder_free_page_range() and binder_allocate_page_range() functions
to provide a more accurate description of what they do. Lets borrow the
freelist concept used in other parts of the kernel for this.

No functional change here.

Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231201172212.1813387-23-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 254650075
(cherry picked from commit ea9cdbf0c7273b55e251b2ed8f85794cfadab5d5
 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
 char-misc-next)
Change-Id: I0d0dfcc6f72d54209da310be2ad5e30f3d722652
[cmllamas: fixed trivial conflicts due to missing commits e33c267ab7
 95a542da5322e]
Signed-off-by: Carlos Llamas <cmllamas@google.com>

drivers/android/binder_alloc.c

@@ -27,7 +27,7 @@
 #include "binder_trace.h"
 #include <trace/hooks/binder.h>
 
-struct list_lru binder_alloc_lru;
+struct list_lru binder_freelist;
 
 static DEFINE_MUTEX(binder_alloc_mmap_lock);
 
@@ -191,8 +191,8 @@ binder_get_installed_page(struct binder_lru_page *lru_page)
 	return smp_load_acquire(&lru_page->page_ptr);
 }
 
-static void binder_free_page_range(struct binder_alloc *alloc,
-				   unsigned long start, unsigned long end)
+static void binder_lru_freelist_add(struct binder_alloc *alloc,
+				    unsigned long start, unsigned long end)
 {
 	struct binder_lru_page *page;
 	unsigned long page_addr;
@@ -211,7 +211,7 @@ static void binder_free_page_range(struct binder_alloc *alloc,
 
 		trace_binder_free_lru_start(alloc, index);
 
-		ret = list_lru_add(&binder_alloc_lru, &page->lru);
+		ret = list_lru_add(&binder_freelist, &page->lru);
 		WARN_ON(!ret);
 
 		trace_binder_free_lru_end(alloc, index);
@@ -300,14 +300,14 @@ static int binder_install_buffer_pages(struct binder_alloc *alloc,
 }
 
 /* The range of pages should exclude those shared with other buffers */
-static void binder_allocate_page_range(struct binder_alloc *alloc,
-				       unsigned long start, unsigned long end)
+static void binder_lru_freelist_del(struct binder_alloc *alloc,
+				    unsigned long start, unsigned long end)
 {
 	struct binder_lru_page *page;
 	unsigned long page_addr;
 
 	binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
-			   "%d: allocate pages %lx-%lx\n",
+			   "%d: pages %lx-%lx\n",
 			   alloc->pid, start, end);
 
 	trace_binder_update_page_range(alloc, true, start, end);
@@ -322,7 +322,7 @@ static void binder_allocate_page_range(struct binder_alloc *alloc,
 		if (page->page_ptr) {
 			trace_binder_alloc_lru_start(alloc, index);
 
-			on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
+			on_lru = list_lru_del(&binder_freelist, &page->lru);
 			WARN_ON(!on_lru);
 
 			trace_binder_alloc_lru_end(alloc, index);
@@ -507,8 +507,8 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 	end_page_addr = PAGE_ALIGN(buffer->user_data + size);
 	if (end_page_addr > has_page_addr)
 		end_page_addr = has_page_addr;
-	binder_allocate_page_range(alloc, PAGE_ALIGN(buffer->user_data),
-				   end_page_addr);
+	binder_lru_freelist_del(alloc, PAGE_ALIGN(buffer->user_data),
+				end_page_addr);
 
 	rb_erase(&buffer->rb_node, &alloc->free_buffers);
 	buffer->free = 0;
@@ -674,8 +674,8 @@ static void binder_delete_free_buffer(struct binder_alloc *alloc,
 				   alloc->pid, buffer->user_data,
 				   prev->user_data,
 				   next ? next->user_data : 0);
-		binder_free_page_range(alloc, buffer_start_page(buffer),
-				       buffer_start_page(buffer) + PAGE_SIZE);
+		binder_lru_freelist_add(alloc, buffer_start_page(buffer),
+					buffer_start_page(buffer) + PAGE_SIZE);
 	}
 	list_del(&buffer->entry);
 	kfree(buffer);
@@ -709,8 +709,8 @@ static void binder_free_buf_locked(struct binder_alloc *alloc,
 			      alloc->pid, size, alloc->free_async_space);
 	}
 
-	binder_free_page_range(alloc, PAGE_ALIGN(buffer->user_data),
-			       (buffer->user_data + buffer_size) & PAGE_MASK);
+	binder_lru_freelist_add(alloc, PAGE_ALIGN(buffer->user_data),
+				(buffer->user_data + buffer_size) & PAGE_MASK);
 
 	rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
 	buffer->free = 1;
@@ -960,7 +960,7 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
 			if (!alloc->pages[i].page_ptr)
 				continue;
 
-			on_lru = list_lru_del(&binder_alloc_lru,
+			on_lru = list_lru_del(&binder_freelist,
 					      &alloc->pages[i].lru);
 			page_addr = alloc->buffer + i * PAGE_SIZE;
 			binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
@@ -1159,13 +1159,13 @@ err_get_alloc_mutex_failed:
 static unsigned long
 binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
 {
-	return list_lru_count(&binder_alloc_lru);
+	return list_lru_count(&binder_freelist);
 }
 
 static unsigned long
 binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
-	return list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
+	return list_lru_walk(&binder_freelist, binder_alloc_free_page,
 			    NULL, sc->nr_to_scan);
 }
 
@@ -1193,12 +1193,12 @@ void binder_alloc_init(struct binder_alloc *alloc)
 
 int binder_alloc_shrinker_init(void)
 {
-	int ret = list_lru_init(&binder_alloc_lru);
+	int ret = list_lru_init(&binder_freelist);
 
 	if (ret == 0) {
 		ret = register_shrinker(&binder_shrinker);
 		if (ret)
-			list_lru_destroy(&binder_alloc_lru);
+			list_lru_destroy(&binder_freelist);
 	}
 	return ret;
 }
@@ -1206,7 +1206,7 @@ int binder_alloc_shrinker_init(void)
 void binder_alloc_shrinker_exit(void)
 {
 	unregister_shrinker(&binder_shrinker);
-	list_lru_destroy(&binder_alloc_lru);
+	list_lru_destroy(&binder_freelist);
 }
 
 /**

drivers/android/binder_alloc.h

@@ -15,7 +15,7 @@
 #include <linux/list_lru.h>
 #include <uapi/linux/android/binder.h>
 
-extern struct list_lru binder_alloc_lru;
+extern struct list_lru binder_freelist;
 struct binder_transaction;
 
 /**
@@ -61,7 +61,7 @@ struct binder_buffer {
 /**
  * struct binder_lru_page - page object used for binder shrinker
  * @page_ptr: pointer to physical page in mmap'd space
- * @lru:      entry in binder_alloc_lru
+ * @lru:      entry in binder_freelist
  * @alloc:    binder_alloc for a proc
  */
 struct binder_lru_page {

drivers/android/binder_alloc_selftest.c

@@ -158,8 +158,8 @@ static void binder_selftest_free_page(struct binder_alloc *alloc)
 	int i;
 	unsigned long count;
 
-	while ((count = list_lru_count(&binder_alloc_lru))) {
-		list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
+	while ((count = list_lru_count(&binder_freelist))) {
+		list_lru_walk(&binder_freelist, binder_alloc_free_page,
 			      NULL, count);
 	}
 
@@ -183,7 +183,7 @@ static void binder_selftest_alloc_free(struct binder_alloc *alloc,
 
 	/* Allocate from lru. */
 	binder_selftest_alloc_buf(alloc, buffers, sizes, seq);
-	if (list_lru_count(&binder_alloc_lru))
+	if (list_lru_count(&binder_freelist))
 		pr_err("lru list should be empty but is not\n");
 
 	binder_selftest_free_buf(alloc, buffers, sizes, seq, end);