From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/drivers/dma-buf/dma-heap.c | 59 ++++++++++++++++++++++++++---------------------------------
1 files changed, 26 insertions(+), 33 deletions(-)
diff --git a/kernel/drivers/dma-buf/dma-heap.c b/kernel/drivers/dma-buf/dma-heap.c
index 87f0b06..004f960 100644
--- a/kernel/drivers/dma-buf/dma-heap.c
+++ b/kernel/drivers/dma-buf/dma-heap.c
@@ -11,6 +11,7 @@
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/err.h>
+#include <linux/xarray.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/nospec.h>
@@ -49,9 +50,7 @@
static DEFINE_MUTEX(heap_list_lock);
static dev_t dma_heap_devt;
static struct class *dma_heap_class;
-
-static DEFINE_MUTEX(heap_devnode_lock);
-static DECLARE_BITMAP(heap_devnode_nums, NUM_HEAP_MINORS);
+static DEFINE_XARRAY_ALLOC(dma_heap_minors);
struct dma_heap *dma_heap_find(const char *name)
{
@@ -124,14 +123,11 @@
{
struct dma_heap *heap;
- mutex_lock(&heap_devnode_lock);
- heap = container_of(inode->i_cdev, struct dma_heap, heap_cdev);
+ heap = xa_load(&dma_heap_minors, iminor(inode));
if (!heap) {
pr_err("dma_heap: minor %d unknown.\n", iminor(inode));
- mutex_unlock(&heap_devnode_lock);
return -ENODEV;
}
- mutex_unlock(&heap_devnode_lock);
/* instance data as context */
file->private_data = heap;
@@ -273,9 +269,7 @@
device_destroy(dma_heap_class, heap->heap_devt);
cdev_del(&heap->heap_cdev);
- mutex_lock(&heap_devnode_lock);
- clear_bit(minor, heap_devnode_nums);
- mutex_unlock(&heap_devnode_lock);
+ xa_erase(&dma_heap_minors, minor);
kfree(heap);
}
@@ -320,7 +314,7 @@
struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
{
- struct dma_heap *heap, *err_ret;
+ struct dma_heap *heap, *h, *err_ret;
unsigned int minor;
int ret;
@@ -334,15 +328,6 @@
return ERR_PTR(-EINVAL);
}
- /* check the name is unique */
- heap = dma_heap_find(exp_info->name);
- if (heap) {
- pr_err("dma_heap: Already registered heap named %s\n",
- exp_info->name);
- dma_heap_put(heap);
- return ERR_PTR(-EINVAL);
- }
-
heap = kzalloc(sizeof(*heap), GFP_KERNEL);
if (!heap)
return ERR_PTR(-ENOMEM);
@@ -352,18 +337,14 @@
heap->ops = exp_info->ops;
heap->priv = exp_info->priv;
- /* Part 1: Find a free minor number */
-
- mutex_lock(&heap_devnode_lock);
- minor = find_next_zero_bit(heap_devnode_nums, NUM_HEAP_MINORS, 0);
- if (minor == NUM_HEAP_MINORS) {
- mutex_unlock(&heap_devnode_lock);
+ /* Find unused minor number */
+ ret = xa_alloc(&dma_heap_minors, &minor, heap,
+ XA_LIMIT(0, NUM_HEAP_MINORS - 1), GFP_KERNEL);
+ if (ret < 0) {
pr_err("dma_heap: Unable to get minor number for heap\n");
- err_ret = ERR_PTR(-ENFILE);
+ err_ret = ERR_PTR(ret);
goto err0;
}
- set_bit(minor, heap_devnode_nums);
- mutex_unlock(&heap_devnode_lock);
/* Create device */
heap->heap_devt = MKDEV(MAJOR(dma_heap_devt), minor);
@@ -390,19 +371,31 @@
/* Make sure it doesn't disappear on us */
heap->heap_dev = get_device(heap->heap_dev);
- /* Add heap to the list */
mutex_lock(&heap_list_lock);
+ /* check the name is unique */
+ list_for_each_entry(h, &heap_list, list) {
+ if (!strcmp(h->name, exp_info->name)) {
+ mutex_unlock(&heap_list_lock);
+ pr_err("dma_heap: Already registered heap named %s\n",
+ exp_info->name);
+ err_ret = ERR_PTR(-EINVAL);
+ put_device(heap->heap_dev);
+ goto err3;
+ }
+ }
+
+ /* Add heap to the list */
list_add(&heap->list, &heap_list);
mutex_unlock(&heap_list_lock);
return heap;
+err3:
+ device_destroy(dma_heap_class, heap->heap_devt);
err2:
cdev_del(&heap->heap_cdev);
err1:
- mutex_lock(&heap_devnode_lock);
- clear_bit(minor, heap_devnode_nums);
- mutex_unlock(&heap_devnode_lock);
+ xa_erase(&dma_heap_minors, minor);
err0:
kfree(heap);
return err_ret;
--
Gitblit v1.6.2