#include <linux/device.h>
#include <linux/dma-map-ops.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/module.h>
#define NR_TESTS (100)
struct dma_pool_pair {
dma_addr_t dma;
void *v;
};
struct dmapool_parms {
size_t size;
size_t align;
size_t boundary;
};
static const struct dmapool_parms pool_parms[] = {
{ .size = 16, .align = 16, .boundary = 0 },
{ .size = 64, .align = 64, .boundary = 0 },
{ .size = 256, .align = 256, .boundary = 0 },
{ .size = 1024, .align = 1024, .boundary = 0 },
{ .size = 4096, .align = 4096, .boundary = 0 },
{ .size = 68, .align = 32, .boundary = 4096 },
};
static struct dma_pool *pool;
static struct device test_dev;
static u64 dma_mask;
static inline int nr_blocks(int size)
{
return clamp_t(int, (PAGE_SIZE / size) * 512, 1024, 8192);
}
static int dmapool_test_alloc(struct dma_pool_pair *p, int blocks)
{
int i;
for (i = 0; i < blocks; i++) {
p[i].v = dma_pool_alloc(pool, GFP_KERNEL,
&p[i].dma);
if (!p[i].v)
goto pool_fail;
}
for (i = 0; i < blocks; i++)
dma_pool_free(pool, p[i].v, p[i].dma);
return 0;
pool_fail:
for (--i; i >= 0; i--)
dma_pool_free(pool, p[i].v, p[i].dma);
return -ENOMEM;
}
static int dmapool_test_block(const struct dmapool_parms *parms)
{
int blocks = nr_blocks(parms->size);
ktime_t start_time, end_time;
struct dma_pool_pair *p;
int i, ret;
p = kcalloc(blocks, sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
pool = dma_pool_create("test pool", &test_dev, parms->size,
parms->align, parms->boundary);
if (!pool) {
ret = -ENOMEM;
goto free_pairs;
}
start_time = ktime_get();
for (i = 0; i < NR_TESTS; i++) {
ret = dmapool_test_alloc(p, blocks);
if (ret)
goto free_pool;
if (need_resched())
cond_resched();
}
end_time = ktime_get();
printk("dmapool test: size:%-4zu align:%-4zu blocks:%-4d time:%llu\n",
parms->size, parms->align, blocks,
ktime_us_delta(end_time, start_time));
free_pool:
dma_pool_destroy(pool);
free_pairs:
kfree(p);
return ret;
}
static void dmapool_test_release(struct device *dev)
{
}
static int dmapool_checks(void)
{
int i, ret;
ret = dev_set_name(&test_dev, "dmapool-test");
if (ret)
return ret;
ret = device_register(&test_dev);
if (ret) {
printk("%s: register failed:%d\n", __func__, ret);
goto put_device;
}
test_dev.release = dmapool_test_release;
set_dma_ops(&test_dev, NULL);
test_dev.dma_mask = &dma_mask;
ret = dma_set_mask_and_coherent(&test_dev, DMA_BIT_MASK(64));
if (ret) {
printk("%s: mask failed:%d\n", __func__, ret);
goto del_device;
}
for (i = 0; i < ARRAY_SIZE(pool_parms); i++) {
ret = dmapool_test_block(&pool_parms[i]);
if (ret)
break;
}
del_device:
device_del(&test_dev);
put_device:
put_device(&test_dev);
return ret;
}
static void dmapool_exit(void)
{
}
module_init(dmapool_checks);
module_exit(dmapool_exit);
MODULE_DESCRIPTION("dma_pool timing test");
MODULE_LICENSE("GPL");
