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Message-ID: <44084cbf-7aaf-3e15-9bef-85f4a84381f0@linaro.org>
Date:   Mon, 5 Jun 2023 14:47:23 -0500
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From:   Alex Elder <elder@linaro.org>
Subject: Re: [PATCH v13 02/24] gunyah: Common types and error codes for Gunyah
 hypercalls
To:     Elliot Berman <quic_eberman@quicinc.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
Cc:     Murali Nalajala <quic_mnalajal@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>,
        Carl van Schaik <quic_cvanscha@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
        Will Deacon <will@kernel.org>, Andy Gross <agross@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
References: <20230509204801.2824351-1-quic_eberman@quicinc.com>
 <20230509204801.2824351-3-quic_eberman@quicinc.com>
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On 5/9/23 3:47 PM, Elliot Berman wrote:
> Add architecture-independent standard error codes, types, and macros for
> Gunyah hypercalls.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>

Looks OK to me.

Reviewed-by: Alex Elder <elder@linaro.org>

> ---
>   include/linux/gunyah.h | 83 ++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 83 insertions(+)
>   create mode 100644 include/linux/gunyah.h
> 
> diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
> new file mode 100644
> index 000000000000..a4e8ec91961d
> --- /dev/null
> +++ b/include/linux/gunyah.h
> @@ -0,0 +1,83 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef _LINUX_GUNYAH_H
> +#define _LINUX_GUNYAH_H
> +
> +#include <linux/errno.h>
> +#include <linux/limits.h>
> +
> +/******************************************************************************/
> +/* Common arch-independent definitions for Gunyah hypercalls                  */
> +#define GH_CAPID_INVAL	U64_MAX
> +#define GH_VMID_ROOT_VM	0xff
> +
> +enum gh_error {
> +	GH_ERROR_OK			= 0,
> +	GH_ERROR_UNIMPLEMENTED		= -1,
> +	GH_ERROR_RETRY			= -2,

I know you explained it "should be OK" to use a negative
value (with unspecified bit width) here.  I continue to
feel it's not well-enough specified for an external API,
but I'm going to try to just let it go.

> +	GH_ERROR_ARG_INVAL		= 1,
> +	GH_ERROR_ARG_SIZE		= 2,
> +	GH_ERROR_ARG_ALIGN		= 3,
> +
> +	GH_ERROR_NOMEM			= 10,
> +
> +	GH_ERROR_ADDR_OVFL		= 20,
> +	GH_ERROR_ADDR_UNFL		= 21,
> +	GH_ERROR_ADDR_INVAL		= 22,
> +
> +	GH_ERROR_DENIED			= 30,
> +	GH_ERROR_BUSY			= 31,
> +	GH_ERROR_IDLE			= 32,
> +
> +	GH_ERROR_IRQ_BOUND		= 40,
> +	GH_ERROR_IRQ_UNBOUND		= 41,
> +
> +	GH_ERROR_CSPACE_CAP_NULL	= 50,
> +	GH_ERROR_CSPACE_CAP_REVOKED	= 51,
> +	GH_ERROR_CSPACE_WRONG_OBJ_TYPE	= 52,
> +	GH_ERROR_CSPACE_INSUF_RIGHTS	= 53,
> +	GH_ERROR_CSPACE_FULL		= 54,
> +
> +	GH_ERROR_MSGQUEUE_EMPTY		= 60,
> +	GH_ERROR_MSGQUEUE_FULL		= 61,
> +};
> +
> +/**
> + * gh_error_remap() - Remap Gunyah hypervisor errors into a Linux error code
> + * @gh_error: Gunyah hypercall return value
> + */
> +static inline int gh_error_remap(enum gh_error gh_error)
> +{
> +	switch (gh_error) {
> +	case GH_ERROR_OK:
> +		return 0;
> +	case GH_ERROR_NOMEM:
> +		return -ENOMEM;
> +	case GH_ERROR_DENIED:
> +	case GH_ERROR_CSPACE_CAP_NULL:
> +	case GH_ERROR_CSPACE_CAP_REVOKED:
> +	case GH_ERROR_CSPACE_WRONG_OBJ_TYPE:
> +	case GH_ERROR_CSPACE_INSUF_RIGHTS:
> +	case GH_ERROR_CSPACE_FULL:
> +		return -EACCES;
> +	case GH_ERROR_BUSY:
> +	case GH_ERROR_IDLE:
> +		return -EBUSY;
> +	case GH_ERROR_IRQ_BOUND:
> +	case GH_ERROR_IRQ_UNBOUND:
> +	case GH_ERROR_MSGQUEUE_FULL:
> +	case GH_ERROR_MSGQUEUE_EMPTY:
> +		return -EIO;
> +	case GH_ERROR_UNIMPLEMENTED:
> +	case GH_ERROR_RETRY:
> +		return -EOPNOTSUPP;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +#endif