Subject: Re: [PATCH v4 03/13] dma-pool: track decrypted atomic pools and select them via attrs

From: Aneesh Kumar K.V <[email-masked]>
Date: Thu, 14 May 2026 12:30:54 +0530

Mostafa Saleh <[email-masked]> writes:

...

>>  struct page *dma_alloc_from_pool(struct device *dev, size_t size,
>> -		void **cpu_addr, gfp_t gfp,
>> +		void **cpu_addr, gfp_t gfp, unsigned long attrs,
>>  		bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
>>  {
>> -	struct gen_pool *pool = NULL;
>> +	struct dma_gen_pool *dma_pool = NULL;
>>  	struct page *page;
>>  	bool pool_found = false;
>>  
>> -	while ((pool = dma_guess_pool(pool, gfp))) {
>> +	while ((dma_pool = dma_guess_pool(dma_pool, gfp))) {
>> +
>> +		if (dma_pool->unencrypted != !!(attrs & DMA_ATTR_CC_SHARED))
>> +			continue;
>> +
>
> nit: If we fail to find a matching pool, a slightly misleading message
> is printed as pool_found = false
>

The message printed is

	WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));

That is correct, isn’t it? The kernel failed to find a pool with the
correct encryption attribute. For example, the request was for an
encrypted allocation from the pool, but no encrypted pool was available.

>
>>  		pool_found = true;
>> -		page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
>> +		page = __dma_alloc_from_pool(dev, size, dma_pool->pool, cpu_addr,
>>  					     phys_addr_ok);
>>  		if (page)
>>  			return page;
>> @@ -296,12 +345,14 @@ struct page *dma_alloc_from_pool(struct device *dev, size_t size,

-aneesh