[PATCH v3 1/1] env: sf: single function env_sf_save()
Harry Waschkeit
harry.waschkeit at men.de
Wed Mar 3 18:52:11 CET 2021
On 03.03.21 00:06, Sean Anderson wrote:
> On 3/2/21 1:09 PM, Harry Waschkeit wrote:
>> Hello Sean,
>>
>> On 02.03.21 00:10, Sean Anderson wrote:
>>> On 3/1/21 11:39 AM, Harry Waschkeit wrote:
>>>> Hi again,
>>>>
>>>> gentle ping for that patch, also in view of subsequently sent patch ...
>>>>
>>>> https://lists.denx.de/pipermail/u-boot/2021-February/439797.html
>>>>
>>>> ... which saw a competing patch by Patrick Delaunay a week later:
>>>>
>>>> https://lists.denx.de/pipermail/u-boot/2021-February/440769.html
>>>>
>>>> However, the latter doesn't seem to take embedded environments into account.
>>>
>>> Can you give an example of where your patch would work while Patrick's wouldn't?
>>
>> I didn't dig too deep into Patrick's patch and maybe I simply miss
>> something important, but I don't even see an spi_flash_erase() in his
>> code, so I'm wondering how it could work at all.
>
> Writing to SPI flash can only set bits to 0. To set bits to 1 you must
> erase them. Conceptually, write(buf) does
>
> flash[i] &= buf[i];
>
> And erase() does
>
> flash[i] = -1;
>
> So writing 0s always succeeds, and we are certain to invalidate the
> environment (as long as our hash has a non-zero value for an all-zero
> input).
Sure.
So it's only the name that is confusing because there's no erase happening at all in env_sf_erase(), a real flash erase is necessary afterwards if you want to write data to environment space.
I think it would be worth a comment in the function then, maybe also others get confused what a function called something with erase actually does with flash data ;-)
>> What I do see in his code is spi_flash_write() with a CONFIG_ENV_SIZE
>> worth of zeroes to the environment environment offset, but this can
>> only work for an erased flash as far as I know.
>
> env_sf_save always erases the environment before flashing. So your patch
> effectively erases env twice before writing to it.
Yeah, you're right, it was made under the false assumption that the erase function actually should erase something ... ;-/
>> And erasing the flash part where the environment is stored should take
>> an environment sizes below sector size into account; the rest of the
>> environment sector could be used otherwise, i.e. CONFIG_ENV_SIZE <
>> CONFIG_ENV_SECT_SIZE.
>
> Right, but typically we have a write granularity of one byte for SPI
> flashes. So you can clear only the environment, and let enf_sf_save deal
> with other data in the sector.
Correct.
So my patches are actually worthless ... interesting that Patrick came up with his patches only right after my attempts to add that functionality, but not discussing my approach.
I'd loved to make a small contribution to U-Boot, maybe I've more luck next time ... ;-)
Best regards,
Harry
> --Sean
>
>> Function env_sf_save() takes care of all of that, so does the
>> env_sf_erase() in my patch, Patrick's version of env_sf_erase() does
>> not.
>>
>> (side note: using more than a flash sector for environment and sharing
>> the last one with different data isn't handled at all at the moment,
>> probably because it was never needed)
>>
>> Best regards,
>> Harry
>>
>>>
>>> Thanks.
>>>
>>> --Sean
>>>
>>>>
>>>> Best regards,
>>>> Harry
>>>>
>>>>
>>>> On 02.02.21 09:21, Harry Waschkeit wrote:
>>>>> Instead of implementing redundant environments in two very similar
>>>>> functions env_sf_save(), handle redundancy in one function, placing the
>>>>> few differences in appropriate pre-compiler sections depending on config
>>>>> option CONFIG_ENV_OFFSET_REDUND.
>>>>>
>>>>> Additionally, several checkpatch complaints were addressed.
>>>>>
>>>>> This patch is in preparation for adding support for env erase.
>>>>>
>>>>> Signed-off-by: Harry Waschkeit <Harry.Waschkeit at men.de>
>>>>> Reviewed-by: Stefan Roese <sr at denx.de>
>>>>> ---
>>>>> Change in v3:
>>>>> - no change in patch, only added "reviewed-by" to commit log
>>>>>
>>>>> Change in v2:
>>>>> - remove one more #ifdef, instead take advantage of compiler attribute
>>>>> __maybe_unused for one variable used only in case of redundant
>>>>> environments
>>>>>
>>>>> env/sf.c | 130 ++++++++++++++++++-------------------------------------
>>>>> 1 file changed, 41 insertions(+), 89 deletions(-)
>>>>>
>>>>> diff --git a/env/sf.c b/env/sf.c
>>>>> index 937778aa37..199114fd3b 100644
>>>>> --- a/env/sf.c
>>>>> +++ b/env/sf.c
>>>>> @@ -66,13 +66,14 @@ static int setup_flash_device(void)
>>>>> return 0;
>>>>> }
>>>>> -#if defined(CONFIG_ENV_OFFSET_REDUND)
>>>>> static int env_sf_save(void)
>>>>> {
>>>>> env_t env_new;
>>>>> - char *saved_buffer = NULL, flag = ENV_REDUND_OBSOLETE;
>>>>> + char *saved_buffer = NULL;
>>>>> u32 saved_size, saved_offset, sector;
>>>>> + ulong offset;
>>>>> int ret;
>>>>> + __maybe_unused char flag = ENV_REDUND_OBSOLETE;
>>>>> ret = setup_flash_device();
>>>>> if (ret)
>>>>> @@ -81,27 +82,33 @@ static int env_sf_save(void)
>>>>> ret = env_export(&env_new);
>>>>> if (ret)
>>>>> return -EIO;
>>>>> - env_new.flags = ENV_REDUND_ACTIVE;
>>>>> - if (gd->env_valid == ENV_VALID) {
>>>>> - env_new_offset = CONFIG_ENV_OFFSET_REDUND;
>>>>> - env_offset = CONFIG_ENV_OFFSET;
>>>>> - } else {
>>>>> - env_new_offset = CONFIG_ENV_OFFSET;
>>>>> - env_offset = CONFIG_ENV_OFFSET_REDUND;
>>>>> - }
>>>>> +#if CONFIG_IS_ENABLED(SYS_REDUNDAND_ENVIRONMENT)
>>>>> + env_new.flags = ENV_REDUND_ACTIVE;
>>>>> +
>>>>> + if (gd->env_valid == ENV_VALID) {
>>>>> + env_new_offset = CONFIG_ENV_OFFSET_REDUND;
>>>>> + env_offset = CONFIG_ENV_OFFSET;
>>>>> + } else {
>>>>> + env_new_offset = CONFIG_ENV_OFFSET;
>>>>> + env_offset = CONFIG_ENV_OFFSET_REDUND;
>>>>> + }
>>>>> + offset = env_new_offset;
>>>>> +#else
>>>>> + offset = CONFIG_ENV_OFFSET;
>>>>> +#endif
>>>>> /* Is the sector larger than the env (i.e. embedded) */
>>>>> if (CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE) {
>>>>> saved_size =CONFIG_ENV_SECT_SIZE - CONFIG_ENV_SIZE;
>>>>> - saved_offset = env_new_offset + CONFIG_ENV_SIZE;
>>>>> + saved_offset = offset +CONFIG_ENV_SIZE;
>>>>> saved_buffer = memalign(ARCH_DMA_MINALIGN, saved_size);
>>>>> if (!saved_buffer) {
>>>>> ret = -ENOMEM;
>>>>> goto done;
>>>>> }
>>>>> - ret = spi_flash_read(env_flash, saved_offset,
>>>>> - saved_size, saved_buffer);
>>>>> + ret = spi_flash_read(env_flash, saved_offset, saved_size,
>>>>> + saved_buffer);
>>>>> if (ret)
>>>>> goto done;
>>>>> }
>>>>> @@ -109,35 +116,39 @@ static int env_sf_save(void)
>>>>> sector = DIV_ROUND_UP(CONFIG_ENV_SIZE, CONFIG_ENV_SECT_SIZE);
>>>>> puts("Erasing SPI flash...");
>>>>> - ret = spi_flash_erase(env_flash, env_new_offset,
>>>>> - sector * CONFIG_ENV_SECT_SIZE);
>>>>> + ret = spi_flash_erase(env_flash, offset,
>>>>> + sector * CONFIG_ENV_SECT_SIZE);
>>>>> if (ret)
>>>>> goto done;
>>>>> puts("Writing to SPI flash...");
>>>>> - ret = spi_flash_write(env_flash, env_new_offset,
>>>>> - CONFIG_ENV_SIZE, &env_new);
>>>>> + ret = spi_flash_write(env_flash, offset,
>>>>> + CONFIG_ENV_SIZE, &env_new);
>>>>> if (ret)
>>>>> goto done;
>>>>> if (CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE) {
>>>>> - ret = spi_flash_write(env_flash, saved_offset,
>>>>> - saved_size, saved_buffer);
>>>>> + ret = spi_flash_write(env_flash, saved_offset, saved_size,
>>>>> + saved_buffer);
>>>>> if (ret)
>>>>> goto done;
>>>>> }
>>>>> - ret = spi_flash_write(env_flash, env_offset + offsetof(env_t, flags),
>>>>> - sizeof(env_new.flags), &flag);
>>>>> - if (ret)
>>>>> - goto done;
>>>>> +#if CONFIG_IS_ENABLED(SYS_REDUNDAND_ENVIRONMENT)
>>>>> + ret = spi_flash_write(env_flash, env_offset + offsetof(env_t, flags),
>>>>> + sizeof(env_new.flags), &flag);
>>>>> + if (ret)
>>>>> + goto done;
>>>>> - puts("done\n");
>>>>> + puts("done\n");
>>>>> - gd->env_valid = gd->env_valid == ENV_REDUND? ENV_VALID : ENV_REDUND;
>>>>> + gd->env_valid = gd->env_valid == ENV_REDUND ? ENV_VALID : ENV_REDUND;
>>>>> - printf("Valid environment: %d\n", (int)gd->env_valid);
>>>>> + printf("Valid environment: %d\n", (int)gd->env_valid);
>>>>> +#else
>>>>> + puts("done\n");
>>>>> +#endif
>>>>> done:
>>>>> if (saved_buffer)
>>>>> @@ -146,6 +157,7 @@ static int env_sf_save(void)
>>>>> return ret;
>>>>> }
>>>>> +#if CONFIG_IS_ENABLED(SYS_REDUNDAND_ENVIRONMENT)
>>>>> static int env_sf_load(void)
>>>>> {
>>>>> int ret;
>>>>> @@ -183,66 +195,6 @@ out:
>>>>> return ret;
>>>>> }
>>>>> #else
>>>>> -static int env_sf_save(void)
>>>>> -{
>>>>> - u32 saved_size, saved_offset, sector;
>>>>> - char *saved_buffer = NULL;
>>>>> - int ret = 1;
>>>>> - env_t env_new;
>>>>> -
>>>>> - ret = setup_flash_device();
>>>>> - if (ret)
>>>>> - return ret;
>>>>> -
>>>>> - /* Is the sector larger than the env (i.e. embedded) */
>>>>> - if (CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE) {
>>>>> - saved_size = CONFIG_ENV_SECT_SIZE - CONFIG_ENV_SIZE;
>>>>> - saved_offset = CONFIG_ENV_OFFSET + CONFIG_ENV_SIZE;
>>>>> - saved_buffer = malloc(saved_size);
>>>>> - if (!saved_buffer)
>>>>> - goto done;
>>>>> -
>>>>> - ret = spi_flash_read(env_flash, saved_offset,
>>>>> - saved_size, saved_buffer);
>>>>> - if (ret)
>>>>> - goto done;
>>>>> - }
>>>>> -
>>>>> - ret = env_export(&env_new);
>>>>> - if (ret)
>>>>> - goto done;
>>>>> -
>>>>> - sector = DIV_ROUND_UP(CONFIG_ENV_SIZE, CONFIG_ENV_SECT_SIZE);
>>>>> -
>>>>> - puts("Erasing SPI flash...");
>>>>> - ret = spi_flash_erase(env_flash, CONFIG_ENV_OFFSET,
>>>>> - sector * CONFIG_ENV_SECT_SIZE);
>>>>> - if (ret)
>>>>> - goto done;
>>>>> -
>>>>> - puts("Writing to SPI flash...");
>>>>> - ret = spi_flash_write(env_flash, CONFIG_ENV_OFFSET,
>>>>> - CONFIG_ENV_SIZE, &env_new);
>>>>> - if (ret)
>>>>> - goto done;
>>>>> -
>>>>> - if (CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE) {
>>>>> - ret = spi_flash_write(env_flash, saved_offset,
>>>>> - saved_size, saved_buffer);
>>>>> - if (ret)
>>>>> - goto done;
>>>>> - }
>>>>> -
>>>>> - ret = 0;
>>>>> - puts("done\n");
>>>>> -
>>>>> - done:
>>>>> - if (saved_buffer)
>>>>> - free(saved_buffer);
>>>>> -
>>>>> - return ret;
>>>>> -}
>>>>> -
>>>>> static int env_sf_load(void)
>>>>> {
>>>>> int ret;
>>>>> @@ -258,8 +210,8 @@ static int env_sf_load(void)
>>>>> if (ret)
>>>>> goto out;
>>>>> - ret = spi_flash_read(env_flash,
>>>>> - CONFIG_ENV_OFFSET, CONFIG_ENV_SIZE, buf);
>>>>> + ret = spi_flash_read(env_flash, CONFIG_ENV_OFFSET, CONFIG_ENV_SIZE,
>>>>> + buf);
>>>>> if (ret) {
>>>>> env_set_default("spi_flash_read() failed", 0);
>>>>> goto err_read;
>>>>> @@ -292,7 +244,7 @@ static int env_sf_init(void)
>>>>> env_t *env_ptr = (env_t *)env_sf_get_env_addr();
>>>>> if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
>>>>> - gd->env_addr = (ulong)&(env_ptr->data);
>>>>> + gd->env_addr = (ulong)&env_ptr->data;
>>>>> gd->env_valid = 1;
>>>>> } else {
>>>>> gd->env_addr = (ulong)&default_environment[0];
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>
--
Harry Waschkeit - Software Engineer
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