Re: [PATCH v4] remoteproc: uclass: Add methods to load firmware to rproc and boot rproc

MD Danish Anwar
2024-02-07T07:16:05Z

Hi Roger

On 06/02/24 7:11 pm, Roger Quadros wrote:
>
>
> On 06/02/2024 07:31, MD Danish Anwar wrote:
>>
>>
>> On 05/02/24 6:07 pm, Roger Quadros wrote:
>>>
>>>
>>> On 05/02/2024 12:20, MD Danish Anwar wrote:
>>>>
>>>>
>>>> On 05/02/24 3:36 pm, Roger Quadros wrote:
>>>>>
>>>>>
>>>>> On 02/02/2024 18:40, Anwar, Md Danish wrote:
>>>>>> Hi Roger,
>>>>>>
>>>>>> On 2/2/2024 4:49 PM, Roger Quadros wrote:
>>>>>>>
>>>>>>>
>>>>>>> On 30/01/2024 08:33, MD Danish Anwar wrote:
>>>>>>>> Add APIs to set a firmware_name to a rproc and boot the rproc with the
>>>>>>>> same firmware.
>>>>>>>>
>>
>> <snip>
>>
>>>>>>
>>>>>>> How does caller know what firmware size to set to?
>>>>>>> This should already be private to the rproc as it knows
>>>>>>> how large is its program memory.
>>>>>>>
>>>>>>
>>>>>> Caller is trying to boot the rproc with a firmware binary. Caller should
>>>>>> know the size of binary that it wants to load to rproc core. Caller will
>>>>>> specify the binary size to rproc_boot(). Based on the size provided by
>>>>>> caller, rproc_boot() will then allocate that much memory and call
>>>>>> request_firmware_into_buf() with the size and allocated buffer. If the
>>>>>> caller doesn't provide minimum size rproc_load() will fail.
>>>>>
>>>>> Caller only knows the filename. It need not know more details.
>>>>
>>>> Caller is trying to load a file of it's choice to a rproc. Caller should
>>>> know the size of file it is trying to load or atleast the max size that
>>>> the firmware file could be of.
>>>>
>>>>
>>>>> Also see my comment below about rproc_boot() API.
>>>>>
>>>>>>
>>>>>> rproc_load() calls respective driver ops, for example: pru_load().
>>>>>> pru_load() [1] API checks the required size of firmware to load by
>>>>>> casting the buffer into Elf32_Ehdr and Elf32_Phdr and returns error if
>>>>>> size provided by caller is less than this.
>>>>>>
>>>>>>
>>>>>> if (offset + filesz > size) {
>>>>>> dev_dbg(dev, "truncated fw: need 0x%x avail 0x%zx\n",
>>>>>> offset + filesz, size);
>>>>>> ret = -EINVAL;
>>>>>> break;
>>>>>> }
>>>>>>
>>>>>>>> + *
>>>>>>>> + * Boot a remote processor (i.e. load its firmware, power it on, ...).
>>>>>>>> + *
>>>>>>>> + * This function first loads the firmware set in the uclass pdata of Remote
>>>>>>>> + * processor to a buffer and then loads firmware to the remote processor
>>>>>>>> + * using rproc_load().
>>>>>>>> + *
>>>>>>>> + * Return: 0 on success, and an appropriate error value otherwise
>>>>>>>> + */
>>>>>>>> +int rproc_boot(struct udevice *rproc_dev, size_t fw_size);
>>>>>>>
>>>>>>> Was wondering if you need separate API for rproc_set_firmware or we can just
>>>>>>> pass firmware name as argument to rproc_boot()?
>>>>>>>
>>>>>>
>>>>>> Technically we can. But when we discussed this approach first in v1, you
>>>>>> had asked to keep the APIs similar to upstream linux. Upstream linux has
>>>>>> these two APIs so I kept it that way. If you want I can drop the first
>>>>>> API. Please let me know.
>>>>>
>>>>> Sure you can keep it as it is in Linux, but there, rproc_boot doesn't
>>>>> take fw_size argument. So wondering why you should have it in u-boot.
>>>>>
>>>>
>>>> For loading firmware to a rproc core in u-boot, it's first neccassry to
>>>> load the firmware into buffer and then load that buffer into rproc core
>>>> using rproc_load() API. Now to load the firmware to a buffer ther is an
>>>> API request_firmware_into_buf(). This API takes size of firmware as one
>>>> of it's argument. So in order to call this API from rproc_boot() we need
>>>> to pass fw_size to rproc_boot()
>>>>
>>>> Other u-boot drivers using request_firmware_into_buf() are also passing
>>>> size of firmware from their driver.
>>>
>>> But in your driver you didn't use size of firmware but some 64K
>>> https://lore.kernel.org/all/20240124064930.1787929-8-danishanwar@ti.com/
>>>
>>
>> Yes, in driver I am hardcoding the size to 64K. That's because I know
>> the size of ICSSG firmwares are less than 64K. Instead of hardcoding I
>
> What if you enable debugging symbols in the firmware file. Won't it exceed 64KB?
> It is not a good idea to assume any firmware file size as it will eventually
> break sometime in the future and will be a pain to debug.
>
>> can also define macro or provide a config option where we set the size
>> and the driver will read the size from the config and call rproc_boot()
>> with size.
>>
>> For example, fm.c driver reads the size from config option
>> CONFIG_SYS_QE_FMAN_FW_LENGTH [1] and calls request_firmware_into_buf()
>>
>> [1]
>> https://elixir.bootlin.com/u-boot/latest/source/drivers/net/fm/fm.c#L458
>>
>>> So neither does the caller have a clue of firmware size?
>>>
>>>>
>>>> If rproc_boot() doesn't take fw_size as argument then within
>>>> rproc_boot() we need to figure out the fw_size before calling
>>>> request_firmware_into_buf().
>>>>
>>>> If we don't know the size / maximum size of the firmware to load, how
>>>> will we call request_firmware_into_buf(). Someone has to tell
>>>> request_firmware_into_buf() the size of firmware. I am expecting that to
>>>> be the caller. Do you have any other way of getting the firmware size
>>>> before request_firmware_into_buf() is called?
>>>
>>> /**
>>> * request_firmware_into_buf - Load firmware into a previously allocated buffer.
>>> * @dev: An instance of a driver.
>>> * @name: Name of firmware file.
>>> * @buf: Address of buffer to load firmware into.
>>> * @size: Size of buffer.
>>> * @offset: Offset of a file for start reading into buffer.
>>>
>>> It needs size of pre-allocated buffer which can be smaller than file size.
>>> It also has the option of offset. So you can load portions of the file limited
>>> by buffer size.
>>>
>>> My suggestion is that Remoteproc layer should take care of how much buffer
>>> to allocate and pass that buffer size to request_firmware_into_buf().
>>> You are doing the malloc here itself anyways.
>>>
>>
>> But how would the remoteproc driver know how much buffer it needs to
>> allocate before calling request_firmware_into_buf().
>
> Only the filesystem driver knows what exactly is the firmware file size.
> fs_size() API can be used for that.
>

To use fs_size() we first need to call fs_set_blk_dev() to set the
storage interface, device partition and fs_type. eg.
fs_set_blk_dev("mmc, "1:2", FS_TYPE_ANY)

Since we are setting the envs for storage_interface and partition I'll
use the envs to call fs_set_blk_dev()

This is how rproc_boot() will look now.

int rproc_boot(struct udevice *rproc_dev)
{
struct dm_rproc_uclass_pdata *uc_pdata;
char *storage_interface, *dev_part;
struct udevice *fs_loader;
int core_id, ret = 0;
char *firmware;
loff_t fw_size;
void *addr;

if (!rproc_dev)
return -EINVAL;

uc_pdata = dev_get_uclass_plat(rproc_dev);
if (!uc_pdata)
return -EINVAL;

core_id = dev_seq(rproc_dev);
firmware = uc_pdata->fw_name;

if (!firmware) {
debug("No firmware set for rproc core %d\n", core_id);
return -EINVAL;
}

/* Initialize all rproc cores */
if (!rproc_is_initialized()) {
ret = rproc_init();
if (ret) {
debug("rproc_init() failed: %d\n", ret);
return ret;
}
}

/* Loading firmware to a given address */
ret = get_fs_loader(&fs_loader);
if (ret) {
debug("could not get fs loader: %d\n", ret);
return ret;
}

storage_interface = env_get("fw_storage_interface");
dev_part = env_get("fw_dev_part");

if (storage_interface && dev_part) {
ret = fs_set_blk_dev(storage_interface, dev_part, FS_TYPE_ANY);
} else {
debug("could not get env variables to load firmware\n");
return -EINVAL;
}

if (ret) {
debug("fs_set_blk_dev failed %d\n", ret);
return ret;
}

ret = fs_size(firmware, &fw_size);
if (ret) {
debug("could not get firmware size %s: %d\n", firmware, ret);
return ret;
}

addr = malloc(fw_size);
if (!addr)
return -ENOMEM;

ret = request_firmware_into_buf(fs_loader, firmware, addr, fw_size, 0);
if (ret < 0) {
debug("could not request %s: %d\n", firmware, ret);
goto free_buffer;
}

ret = rproc_load(core_id, (ulong)addr, ret);
if (ret) {
debug("failed to load %s to rproc core %d from addr 0x%08lX err %d\n",
uc_pdata->fw_name, core_id, (ulong)addr, ret);
goto free_buffer;
}

ret = rproc_start(core_id);
if (ret)
debug("failed to start rproc core %d\n", core_id);

free_buffer:
free(addr);
return ret;
}

Please let me know if this looks ok. Without calling fs_set_blk_dev()
first, fs_size() results in error.

>>
>>>>
>>>>>>
>>>>>>>> #else
>>>>>>>> static inline int rproc_init(void) { return -ENOSYS; }
>>>>>>>> static inline int rproc_dev_init(int id) { return -ENOSYS; }
>>>>>>>> @@ -744,6 +775,10 @@ static inline int rproc_elf_load_rsc_table(struct udevice *dev, ulong fw_addr,
>>>>>>>> ulong fw_size, ulong *rsc_addr,
>>>>>>>> ulong *rsc_size)
>>>>>>>> { return -ENOSYS; }
>>>>>>>> +static inline int rproc_set_firmware(struct udevice *rproc_dev, const char *fw_name)
>>>>>>>> +{ return -ENOSYS; }
>>>>>>>> +static inline int rproc_boot(struct udevice *rproc_dev, size_t fw_size)
>>>>>>>> +{ return -ENOSYS; }
>>>>>>>> #endif
>>>>>>>>
>>>>>>>> #endif /* _RPROC_H_ */
>>>>>>>
>>>>>>
>>>>>> [1]
>>>>>> https://elixir.bootlin.com/u-boot/latest/source/drivers/remoteproc/pru_rproc.c#L324
>>>>>>
>>>>>
>>>>
>>>
>>
>

--
Thanks and Regards,
Danish