linux-kernel - Re: [PATCH 2/2] nvmem: imx: scu: support write

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <dd82e84d-ab22-9dd9-f895-776570f46fee@linaro.org>
Date:   Fri, 6 Sep 2019 10:37:44 +0100
From:   Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
To:     Peng Fan <peng.fan@....com>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>
Cc:     "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Aisheng Dong <aisheng.dong@....com>
Subject: Re: [PATCH 2/2] nvmem: imx: scu: support write



On 06/09/2019 07:57, Peng Fan wrote:
>> Subject: [PATCH 2/2] nvmem: imx: scu: support write
> 
> Ping..
> 
Thanks for your patience!
I normally do not take patches after rc5 for nvmem.
These will be applied after rc1 is released!

Thanks,
srini
> Thanks,
> Peng.
> 
>>
>> From: Peng Fan <peng.fan@....com>
>>
>> The fuse programming from non-secure world is blocked, so we could only use
>> Arm Trusted Firmware SIP call to let ATF program fuse.
>>
>> Because there is ECC region that could only be programmed once, so add a
>> heler in_ecc to check the ecc region.
>>
>> Signed-off-by: Peng Fan <peng.fan@....com>
>> ---
>>
>> The ATF patch will soon be posted to ATF community.
>>
>>   drivers/nvmem/imx-ocotp-scu.c | 73
>> ++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 72 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
>> index 2f339d7432e6..0f064f2e74a8 100644
>> --- a/drivers/nvmem/imx-ocotp-scu.c
>> +++ b/drivers/nvmem/imx-ocotp-scu.c
>> @@ -7,6 +7,7 @@
>>    * Peng Fan <peng.fan@....com>
>>    */
>>
>> +#include <linux/arm-smccc.h>
>>   #include <linux/firmware/imx/sci.h>
>>   #include <linux/module.h>
>>   #include <linux/nvmem-provider.h>
>> @@ -14,6 +15,9 @@
>>   #include <linux/platform_device.h>
>>   #include <linux/slab.h>
>>
>> +#define IMX_SIP_OTP			0xC200000A
>> +#define IMX_SIP_OTP_WRITE		0x2
>> +
>>   enum ocotp_devtype {
>>   	IMX8QXP,
>>   };
>> @@ -45,6 +49,8 @@ struct imx_sc_msg_misc_fuse_read {
>>   	u32 word;
>>   } __packed;
>>
>> +static DEFINE_MUTEX(scu_ocotp_mutex);
>> +
>>   static struct ocotp_devtype_data imx8qxp_data = {
>>   	.devtype = IMX8QXP,
>>   	.nregs = 800,
>> @@ -73,6 +79,23 @@ static bool in_hole(void *context, u32 index)
>>   	return false;
>>   }
>>
>> +static bool in_ecc(void *context, u32 index) {
>> +	struct ocotp_priv *priv = context;
>> +	const struct ocotp_devtype_data *data = priv->data;
>> +	int i;
>> +
>> +	for (i = 0; i < data->num_region; i++) {
>> +		if (data->region[i].flag & ECC_REGION) {
>> +			if ((index >= data->region[i].start) &&
>> +			    (index <= data->region[i].end))
>> +				return true;
>> +		}
>> +	}
>> +
>> +	return false;
>> +}
>> +
>>   static int imx_sc_misc_otp_fuse_read(struct imx_sc_ipc *ipc, u32 word,
>>   				     u32 *val)
>>   {
>> @@ -116,6 +139,8 @@ static int imx_scu_ocotp_read(void *context,
>> unsigned int offset,
>>   	if (!p)
>>   		return -ENOMEM;
>>
>> +	mutex_lock(&scu_ocotp_mutex);
>> +
>>   	buf = p;
>>
>>   	for (i = index; i < (index + count); i++) { @@ -126,6 +151,7 @@ static int
>> imx_scu_ocotp_read(void *context, unsigned int offset,
>>
>>   		ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, i, buf);
>>   		if (ret) {
>> +			mutex_unlock(&scu_ocotp_mutex);
>>   			kfree(p);
>>   			return ret;
>>   		}
>> @@ -134,18 +160,63 @@ static int imx_scu_ocotp_read(void *context,
>> unsigned int offset,
>>
>>   	memcpy(val, (u8 *)p + offset % 4, bytes);
>>
>> +	mutex_unlock(&scu_ocotp_mutex);
>> +
>>   	kfree(p);
>>
>>   	return 0;
>>   }
>>
>> +static int imx_scu_ocotp_write(void *context, unsigned int offset,
>> +			       void *val, size_t bytes)
>> +{
>> +	struct ocotp_priv *priv = context;
>> +	struct arm_smccc_res res;
>> +	u32 *buf = val;
>> +	u32 tmp;
>> +	u32 index;
>> +	int ret;
>> +
>> +	/* allow only writing one complete OTP word at a time */
>> +	if ((bytes != 4) || (offset % 4))
>> +		return -EINVAL;
>> +
>> +	index = offset >> 2;
>> +
>> +	if (in_hole(context, index))
>> +		return -EINVAL;
>> +
>> +	if (in_ecc(context, index)) {
>> +		pr_warn("ECC region, only program once\n");
>> +		mutex_lock(&scu_ocotp_mutex);
>> +		ret = imx_sc_misc_otp_fuse_read(priv->nvmem_ipc, index, &tmp);
>> +		mutex_unlock(&scu_ocotp_mutex);
>> +		if (ret)
>> +			return ret;
>> +		if (tmp) {
>> +			pr_warn("ECC region, already has value: %x\n", tmp);
>> +			return -EIO;
>> +		}
>> +	}
>> +
>> +	mutex_lock(&scu_ocotp_mutex);
>> +
>> +	arm_smccc_smc(IMX_SIP_OTP, IMX_SIP_OTP_WRITE, index, *buf,
>> +		      0, 0, 0, 0, &res);
>> +
>> +	mutex_unlock(&scu_ocotp_mutex);
>> +
>> +	return res.a0;
>> +}
>> +
>>   static struct nvmem_config imx_scu_ocotp_nvmem_config = {
>>   	.name = "imx-scu-ocotp",
>> -	.read_only = true,
>> +	.read_only = false,
>>   	.word_size = 4,
>>   	.stride = 1,
>>   	.owner = THIS_MODULE,
>>   	.reg_read = imx_scu_ocotp_read,
>> +	.reg_write = imx_scu_ocotp_write,
>>   };
>>
>>   static const struct of_device_id imx_scu_ocotp_dt_ids[] = {
>> --
>> 2.16.4
>