Re: [PATCHv3 05/15] remoteproc/omap: Add the rproc ops .da_to_va() implementation

[Tero Kristo <t-kristo@ti.com>]

On 18/12/2019 02:38, Mathieu Poirier wrote:
> On Fri, Dec 13, 2019 at 02:55:27PM +0200, Tero Kristo wrote:
>> From: Suman Anna <s-anna@ti.com>
>>
>> An implementation for the rproc ops .da_to_va() has been added
>> that provides the address translation between device addresses
>> to kernel virtual addresses for internal RAMs present on that
>> particular remote processor device. The implementation provides
>> the translations based on the addresses parsed and stored during
>> the probe.
>>
>> This ops gets invoked by the exported rproc_da_to_va() function
>> and allows the remoteproc core's ELF loader to be able to load
>> program data directly into the internal memories.
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> ---
>>   drivers/remoteproc/omap_remoteproc.c | 39 ++++++++++++++++++++++++++++
>>   1 file changed, 39 insertions(+)
>>
>> diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c
>> index 844703507a74..28f14e24b389 100644
>> --- a/drivers/remoteproc/omap_remoteproc.c
>> +++ b/drivers/remoteproc/omap_remoteproc.c
>> @@ -232,10 +232,49 @@ static int omap_rproc_stop(struct rproc *rproc)
>>   	return 0;
>>   }
>>   
>> +/**
>> + * omap_rproc_da_to_va() - internal memory translation helper
>> + * @rproc: remote processor to apply the address translation for
>> + * @da: device address to translate
>> + * @len: length of the memory buffer
>> + *
>> + * Custom function implementing the rproc .da_to_va ops to provide address
>> + * translation (device address to kernel virtual address) for internal RAMs
>> + * present in a DSP or IPU device). The translated addresses can be used
>> + * either by the remoteproc core for loading, or by any rpmsg bus drivers.
>> + * Returns the translated virtual address in kernel memory space, or NULL
>> + * in failure.
>> + */
>> +static void *omap_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
>> +{
>> +	struct omap_rproc *oproc = rproc->priv;
>> +	int i;
>> +	u32 offset;
>> +
>> +	if (len <= 0)
>> +		return NULL;
>> +
>> +	if (!oproc->num_mems)
>> +		return NULL;
>> +
>> +	for (i = 0; i < oproc->num_mems; i++) {
>> +		if (da >= oproc->mem[i].dev_addr && da + len <=
> 
> Shouldn't this be '<' rather than '<=' ?

No, I think <= is correct. You need to consider the initial byte in the 
range also. Consider a simple case where you provide the exact da + len 
corresponding to a specific memory range.

> 
>> +		    oproc->mem[i].dev_addr +  oproc->mem[i].size) {
> 
> One space too many after the '+' .

True, I wonder why checkpatch did not catch this.

> 
>> +			offset = da -  oproc->mem[i].dev_addr;
> 
> One space too many after then '-' .

Same, will fix these two.

-Tero

> 
>> +			/* __force to make sparse happy with type conversion */
>> +			return (__force void *)(oproc->mem[i].cpu_addr +
>> +						offset);
>> +		}
>> +	}
>> +
>> +	return NULL;
>> +}
>> +
>>   static const struct rproc_ops omap_rproc_ops = {
>>   	.start		= omap_rproc_start,
>>   	.stop		= omap_rproc_stop,
>>   	.kick		= omap_rproc_kick,
>> +	.da_to_va	= omap_rproc_da_to_va,
>>   };
>>   
>>   static const char * const ipu_mem_names[] = {
>> -- 
>> 2.17.1
>>
>> --

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