[V3 PATCH 15/16] crypto/nx: Get NX capabilities for GZIP coprocessor type

[Nicholas Piggin]

Excerpts from Haren Myneni's message of April 18, 2021 7:12 am:
> 
> phyp provides NX capabilities which gives recommended minimum
> compression / decompression length and maximum request buffer size
> in bytes.
> 
> Changes to get NX overall capabilities which points to the specific
> features phyp supports. Then retrieve NXGZIP specific capabilities.
> 
> Signed-off-by: Haren Myneni <haren at linux.ibm.com>
> ---
>  drivers/crypto/nx/nx-common-pseries.c | 83 +++++++++++++++++++++++++++
>  1 file changed, 83 insertions(+)
> 
> diff --git a/drivers/crypto/nx/nx-common-pseries.c b/drivers/crypto/nx/nx-common-pseries.c
> index 9a40fca8a9e6..49224870d05e 100644
> --- a/drivers/crypto/nx/nx-common-pseries.c
> +++ b/drivers/crypto/nx/nx-common-pseries.c
> @@ -9,6 +9,7 @@
>   */
>  
>  #include <asm/vio.h>
> +#include <asm/hvcall.h>
>  #include <asm/vas.h>
>  
>  #include "nx-842.h"
> @@ -20,6 +21,24 @@ MODULE_DESCRIPTION("842 H/W Compression driver for IBM Power processors");
>  MODULE_ALIAS_CRYPTO("842");
>  MODULE_ALIAS_CRYPTO("842-nx");
>  
> +struct nx_ct_capabs_be {

What does "ct" mean? I've seen it in a few other places too.

> +	__be64	descriptor;
> +	__be64	req_max_processed_len;	/* Max bytes in one GZIP request */
> +	__be64	min_compress_len;	/* Min compression size in bytes */
> +	__be64	min_decompress_len;	/* Min decompression size in bytes */
> +} __packed __aligned(0x1000);
> +
> +struct nx_ct_capabs {
> +	char	name[VAS_DESCR_LEN + 1];
> +	u64	descriptor;
> +	u64	req_max_processed_len;	/* Max bytes in one GZIP request */
> +	u64	min_compress_len;	/* Min compression in bytes */
> +	u64	min_decompress_len;	/* Min decompression in bytes */
> +};
> +
> +u64 capab_feat = 0;

Why is this here and not a local variable?

> +struct nx_ct_capabs nx_ct_capab;

It's okay and generally better to use the same name as the struct name
in this situation, i.e.,

"struct nx_ct_capabs nx_ct_capabs"

(modulo static / caps / etc)

Thanks,
Nick