[Skiboot] [PATCH 09/17] external/pflash: Correct erase alignment checks

[Samuel Mendoza-Jonas]

On Fri, 2017-07-21 at 16:36 +1000, Cyril Bur wrote:
> Either the user has specified sizes manually in which case pflash should
> be as flexible as possible, blocklevel_smart_erase() permits this. To
> prevent possible mistakes pflash will require --force to perform a
> manual erase of unaligned sizes.
> Alternatively they would have used -P to specify a partition, partitions
> aren't necessarily erase granule aligned anymore, pflash should still
> work, blocklevel_smart_erase() will handle - skip the checks in this
> case.

This took me three goes to understand - please English v2 :(

> 
> This commit also starts using write_sizes and standard addresses to pass
> to the erase code since pflash no longer needs to handle erase
> alignment.
> 
> Signed-off-by: Cyril Bur <cyril.bur at au1.ibm.com>
> ---
>  external/pflash/pflash.c | 40 +++++++++++++---------------------------
>  1 file changed, 13 insertions(+), 27 deletions(-)
> 
> diff --git a/external/pflash/pflash.c b/external/pflash/pflash.c
> index c0a63fca..f73ba1c5 100644
> --- a/external/pflash/pflash.c
> +++ b/external/pflash/pflash.c
> @@ -608,7 +608,6 @@ int main(int argc, char *argv[])
>  {
>  	const char *pname = argv[0];
>  	uint32_t address = 0, read_size = 0, write_size = 0, detail_id = UINT_MAX;
> -	uint32_t erase_start = 0, erase_size = 0;
>  	bool erase = false, do_clear = false;
>  	bool program = false, erase_all = false, info = false, do_read = false;
>  	bool enable_4B = false, disable_4B = false;
> @@ -979,33 +978,20 @@ int main(int argc, char *argv[])
>  			goto out;
>  		}
>  
> -
> -		/* If erasing, check partition alignment */
> -		if (erase && ((pstart | pmaxsz) & 0xfff)) {
> -			fprintf(stderr,"Partition not aligned properly\n");
> -			goto out;
> -		}
> -
>  		/* Set address */
>  		address = pstart;
> -	}
> -
> -	/* Align erase boundaries */
> -	if (erase && !erase_all) {
> -		uint32_t mask = 0xfff;
> -		uint32_t erase_end;
> -
> -		/* Dummy size for erase, will be adjusted later */
> -		if (!write_size)
> -			write_size = 1;
> -		erase_start = address & ~mask;
> -		erase_end = ((address + write_size) + mask) & ~mask;
> -		erase_size = erase_end - erase_start;
> -
> -		if (erase_start != address || erase_size != write_size)
> -			fprintf(stderr, "WARNING: Erase region adjusted"
> -				" to 0x%08x..0x%08x\n",
> -				erase_start, erase_end);
> +	} else if (erase) {
> +		if ((address | write_size) & (fl_erase_granule - 1)) {
> +			if (must_confirm) {
> +				printf("ERROR: Erase at 0x%08x for 0x%08x isn't erase block aligned\n",
> +						address, write_size);
> +				printf("Use --force to force\n");
> +				goto out;
> +			} else {
> +				printf("WARNING: Erase at 0x%08x for 0x%08x isn't erase block aligned\n",
> +						address, write_size);
> +			}
> +		}
>  	}
>  
>  	/* Process commands */
> @@ -1039,7 +1025,7 @@ int main(int argc, char *argv[])
>  	if (erase_all)
>  		erase_chip();
>  	else if (erase)
> -		erase_range(erase_start, erase_size, program);
> +		erase_range(address, write_size, program);
>  	if (program)
>  		program_file(write_file, address, write_size);
>  	if (do_clear)