[PATCH] drm/ttm: fix DMA32 handling in the global page pool

[Christian König]

Ping, can I get an rb or at least Acked-by for this?

Thanks in advance,
Christian.

Am 17.11.20 um 16:53 schrieb Christian König:
> When we have mixed DMA32 and non DMA32 device in one system
> it could otherwise happen that the DMA32 device gets pages
> it can't work with.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/ttm/ttm_pool.c | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
> index 1b96780b4989..5455b2044759 100644
> --- a/drivers/gpu/drm/ttm/ttm_pool.c
> +++ b/drivers/gpu/drm/ttm/ttm_pool.c
> @@ -63,6 +63,9 @@ static atomic_long_t allocated_pages;
>   static struct ttm_pool_type global_write_combined[MAX_ORDER];
>   static struct ttm_pool_type global_uncached[MAX_ORDER];
>   
> +static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER];
> +static struct ttm_pool_type global_dma32_uncached[MAX_ORDER];
> +
>   static spinlock_t shrinker_lock;
>   static struct list_head shrinker_list;
>   static struct shrinker mm_shrinker;
> @@ -290,8 +293,14 @@ static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
>   #ifdef CONFIG_X86
>   	switch (caching) {
>   	case ttm_write_combined:
> +		if (pool->use_dma32)
> +			return &global_dma32_write_combined[order];
> +
>   		return &global_write_combined[order];
>   	case ttm_uncached:
> +		if (pool->use_dma32)
> +			return &global_dma32_uncached[order];
> +
>   		return &global_uncached[order];
>   	default:
>   		break;
> @@ -570,6 +579,11 @@ int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m)
>   	seq_puts(m, "uc\t:");
>   	ttm_pool_debugfs_orders(global_uncached, m);
>   
> +	seq_puts(m, "wc 32\t:");
> +	ttm_pool_debugfs_orders(global_dma32_write_combined, m);
> +	seq_puts(m, "uc 32\t:");
> +	ttm_pool_debugfs_orders(global_dma32_uncached, m);
> +
>   	for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
>   		seq_puts(m, "DMA ");
>   		switch (i) {
> @@ -640,6 +654,11 @@ int ttm_pool_mgr_init(unsigned long num_pages)
>   		ttm_pool_type_init(&global_write_combined[i], NULL,
>   				   ttm_write_combined, i);
>   		ttm_pool_type_init(&global_uncached[i], NULL, ttm_uncached, i);
> +
> +		ttm_pool_type_init(&global_dma32_write_combined[i], NULL,
> +				   ttm_write_combined, i);
> +		ttm_pool_type_init(&global_dma32_uncached[i], NULL,
> +				   ttm_uncached, i);
>   	}
>   
>   	mm_shrinker.count_objects = ttm_pool_shrinker_count;
> @@ -660,6 +679,9 @@ void ttm_pool_mgr_fini(void)
>   	for (i = 0; i < MAX_ORDER; ++i) {
>   		ttm_pool_type_fini(&global_write_combined[i]);
>   		ttm_pool_type_fini(&global_uncached[i]);
> +
> +		ttm_pool_type_fini(&global_dma32_write_combined[i]);
> +		ttm_pool_type_fini(&global_dma32_uncached[i]);
>   	}
>   
>   	unregister_shrinker(&mm_shrinker);