Re: [PATCH v9 07/27] virt: gunyah: msgq: Add hypercalls to send and receive messages

[Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>]

On 20/01/2023 22:46, Elliot Berman wrote:
> Add hypercalls to send and receive messages on a Gunyah message queue.
>
> Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
> ---
>   arch/arm64/gunyah/gunyah_hypercall.c | 33 ++++++++++++++++++++++++++++
>   include/linux/gunyah.h               |  5 +++++
>   2 files changed, 38 insertions(+)
>
> diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
> index ffed4b71641f..d93ad2c08479 100644
> --- a/arch/arm64/gunyah/gunyah_hypercall.c
> +++ b/arch/arm64/gunyah/gunyah_hypercall.c
> @@ -13,6 +13,8 @@ static const uint32_t gunyah_known_uuids[][4] = {
>   };
>   
>   #define GH_HYPERCALL_HYP_IDENTIFY		GH_HYPERCALL(0x0000)
> +#define GH_HYPERCALL_MSGQ_SEND			GH_HYPERCALL(0x001B)
> +#define GH_HYPERCALL_MSGQ_RECV			GH_HYPERCALL(0x001C)
>   
>   /**
>    * gh_hypercall_get_uid() - Returns a UID when running under a Gunyah hypervisor
> @@ -71,5 +73,36 @@ void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identi
>   }
>   EXPORT_SYMBOL_GPL(gh_hypercall_hyp_identify);
>   
> +int gh_hypercall_msgq_send(u64 capid, size_t size, uintptr_t buff, int tx_flags, bool *ready)
> +{
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_1_1_hvc(GH_HYPERCALL_MSGQ_SEND, capid, size, buff, tx_flags, 0, &res);
> +
<--
> +	if (res.a0)
> +		return res.a0;
> +
> +	*ready = res.a1;
> +
> +	return res.a0;
-->
this can be made more readable with code something like:

if (res.a0 == SMCCC_RET_SUCCESS)
	*ready = res.a1;

return res.a0;


> +}
> +EXPORT_SYMBOL_GPL(gh_hypercall_msgq_send);
> +
> +int gh_hypercall_msgq_recv(u64 capid, uintptr_t buff, size_t size, size_t *recv_size, bool *ready)
> +{
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_1_1_hvc(GH_HYPERCALL_MSGQ_RECV, capid, buff, size, 0, &res);
> +
> +	if (res.a0)
> +		return res.a0;
> +
> +	*recv_size = res.a1;
> +	*ready = res.a2;
> +
same comment.


> +	return res.a0;
> +}
> +EXPORT_SYMBOL_GPL(gh_hypercall_msgq_recv);
> +
>   MODULE_LICENSE("GPL");
>   MODULE_DESCRIPTION("Gunyah Hypervisor Hypercalls");
> diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
> index 6724d1264d58..b5f61c14ec1e 100644
> --- a/include/linux/gunyah.h
> +++ b/include/linux/gunyah.h
> @@ -104,4 +104,9 @@ struct gh_hypercall_hyp_identify_resp {
>   
>   void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identity);
>   
> +#define GH_HYPERCALL_MSGQ_TX_FLAGS_PUSH		BIT(0)
Please move unrelated changes from  this patch to the patch that 
actually uses these.

> +
> +int gh_hypercall_msgq_send(u64 capid, size_t size, uintptr_t buff, int tx_flags, bool *ready);
> +int gh_hypercall_msgq_recv(u64 capid, uintptr_t buff, size_t size, size_t *recv_size, bool *ready);
> +
>   #endif