On 11/25/2019 12:33 AM, Iuliana Prodan wrote:
> In commit 'a1cf573ee95 ("crypto: caam - select DMA address
> size at runtime")' CAAM pointer size (caam_ptr_size) is changed
> from sizeof(dma_addr_t) to runtime value computed from MCFGR register.
> At some point, the bit for Pointer Size should be reset to 0,
> but only for the case when the CAAM pointer size if 32 bits.
> Therefore, use caam_ptr_size instead of sizeof(dma_addr_t).
>
The logic is circular, see below.
> Fixes: a1cf573ee95 ("crypto: caam - select DMA address size at runtime")
Please Cc the author(s) when adding Fixes tag.
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Iuliana Prodan <iuliana.prodan@xxxxxxx>
> ---
> drivers/crypto/caam/ctrl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
> index d7c3c38..786eef6 100644
> --- a/drivers/crypto/caam/ctrl.c
> +++ b/drivers/crypto/caam/ctrl.c
> @@ -674,7 +674,7 @@ static int caam_probe(struct platform_device *pdev)
> clrsetbits_32(&ctrl->mcr, MCFGR_AWCACHE_MASK | MCFGR_LONG_PTR,
> MCFGR_AWCACHE_CACH | MCFGR_AWCACHE_BUFF |
> MCFGR_WDENABLE | MCFGR_LARGE_BURST |
> - (sizeof(dma_addr_t) == sizeof(u64) ?
> + (caam_ptr_sz == sizeof(u64) ?
> MCFGR_LONG_PTR : 0));
>
Before this in caam_probe() there's:
if (comp_params & CTPR_MS_PS && rd_reg32(&ctrl->mcr) & MCFGR_LONG_PTR)
caam_ptr_sz = sizeof(u64);
else
caam_ptr_sz = sizeof(u32);
thus caam_ptr_sz is determined based on MCFGR:
MCFGR[PS] ==> caam_ptr_sz
so it no longer makes sense to reconfigure MCFGR based on caam_ptr_sz:
caam_ptr_sz ==> MCFGR[PS]
The short-term fix would be to no longer touch MCFGR[PS], which is in line with
commit a1cf573ee95 ("crypto: caam - select DMA address size at runtime")
Note however there's a small issue with the logic of kernel relying on
MCFGR[PS] being previously configured (by U-boot etc.), see
commit 39eaf759466f ("crypto: caam - fix pointer size for AArch64 boot loader, AArch32 kernel")
In the long run, IMO the proper thing for the driver to do is to rely,
whenever possible, on DT ("dma-ranges" property) / dma_mask provided by
the device driver infrastructure, and not on MCFGR[PS]:
[ DT "dma-ranges" ==> ] dma_mask ==> MCFGR[PS], caam_ptr_sz
but that would probably involve too many changes for getting into -stable.
Horia
