Re: [PATCH v4 2/2] firmware: qcom: scm: Add support for ARM64 SoCs

[Christopher Covington <cov@codeaurora.org>]

Hi Kumar,

On 04/27/2015 05:23 PM, Kumar Gala wrote:

> --- /dev/null
> +++ b/drivers/firmware/qcom_scm-64.c
> @@ -0,0 +1,465 @@
> +/* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> + * 02110-1301, USA.
> + */
> +
> +#include <linux/cpumask.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/qcom_scm.h>
> +
> +#include <asm/cacheflush.h>
> +#include <asm/compiler.h>
> +#include <asm/smp_plat.h>
> +
> +#include "qcom_scm.h"
> +
> +#define QCOM_SCM_SIP_FNID(s, c) (((((s) & 0xFF) << 8) | ((c) & 0xFF)) | 0x02000000)
> +
> +#define MAX_QCOM_SCM_ARGS 10
> +#define MAX_QCOM_SCM_RETS 3
> +
> +#define QCOM_SCM_ARGS_IMPL(num, a, b, c, d, e, f, g, h, i, j, ...) (\
> +			(((a) & 0xff) << 4) | \
> +			(((b) & 0xff) << 6) | \
> +			(((c) & 0xff) << 8) | \
> +			(((d) & 0xff) << 10) | \
> +			(((e) & 0xff) << 12) | \
> +			(((f) & 0xff) << 14) | \
> +			(((g) & 0xff) << 16) | \
> +			(((h) & 0xff) << 18) | \
> +			(((i) & 0xff) << 20) | \
> +			(((j) & 0xff) << 22) | \
> +			(num & 0xffff))
> +
> +#define QCOM_SCM_ARGS(...) QCOM_SCM_ARGS_IMPL(__VA_ARGS__, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
> +
> +/**
> + * struct qcom_scm_desc
> + * @arginfo: Metadata describing the arguments in args[]
> + * @args: The array of arguments for the secure syscall
> + * @ret: The values returned by the secure syscall
> + * @extra_arg_buf: The buffer containing extra arguments
> +		   (that don't fit in available registers)
> + * @x5: The 4rd argument to the secure syscall or physical address of
> +	extra_arg_buf
> + */
> +struct qcom_scm_desc {
> +	u32 arginfo;
> +	u64 args[MAX_QCOM_SCM_ARGS];
> +	u64 ret[MAX_QCOM_SCM_RETS];
> +
> +	/* private */
> +	void *extra_arg_buf;
> +	u64 x5;
> +};
> +
> +
> +#define QCOM_SCM_ENOMEM		-5
> +#define QCOM_SCM_EOPNOTSUPP	-4
> +#define QCOM_SCM_EINVAL_ADDR	-3
> +#define QCOM_SCM_EINVAL_ARG	-2
> +#define QCOM_SCM_ERROR		-1
> +#define QCOM_SCM_INTERRUPTED	1
> +#define QCOM_SCM_EBUSY		-55
> +#define QCOM_SCM_V2_EBUSY	-12

Any reason to duplicate ENOMEM through INTERRUPTED rather than put them in the
common header?

> +static DEFINE_MUTEX(qcom_scm_lock);
> +
> +#define QCOM_SCM_EBUSY_WAIT_MS 30
> +#define QCOM_SCM_EBUSY_MAX_RETRY 20
> +
> +#define N_EXT_QCOM_SCM_ARGS 7
> +#define FIRST_EXT_ARG_IDX 3
> +#define SMC_ATOMIC_SYSCALL 31
> +#define N_REGISTER_ARGS (MAX_QCOM_SCM_ARGS - N_EXT_QCOM_SCM_ARGS + 1)
> +#define SMC64_MASK 0x40000000
> +#define SMC_ATOMIC_MASK 0x80000000
> +#define IS_CALL_AVAIL_CMD 1
> +
> +#define R0_STR "x0"
> +#define R1_STR "x1"
> +#define R2_STR "x2"
> +#define R3_STR "x3"
> +#define R4_STR "x4"
> +#define R5_STR "x5"

What is the purpose of these macros?

Chris

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