Date:   Wed, 28 Sep 2022 15:39:53 +0800
From:   Peng Fan <peng.fan@....nxp.com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>,
        Peng Fan <peng.fan@....com>
Cc:     "bjorn.andersson@...nel.org" <bjorn.andersson@...nel.org>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "krzysztof.kozlowski+dt@...aro.org" 
        <krzysztof.kozlowski+dt@...aro.org>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        "linux-remoteproc@...r.kernel.org" <linux-remoteproc@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V5 3/6] remoteproc: imx_rproc: support attaching to
 i.MX8QXP M4



On 9/28/2022 1:56 AM, Mathieu Poirier wrote:
> On Tue, Sep 27, 2022 at 02:48:02AM +0000, Peng Fan wrote:
>> Hi Mathieu,
>>
>> Thanks for reviewing this patchset.
>>> Subject: Re: [PATCH V5 3/6] remoteproc: imx_rproc: support attaching to
>>> i.MX8QXP M4
>>>
>>> On Wed, Aug 24, 2022 at 09:10:20AM +0800, Peng Fan (OSS) wrote:
>>>> From: Peng Fan <peng.fan@....com>
>>>>
>>>> When M4 is kicked by SCFW, M4 runs in its own hardware partition,
>>>> Linux could only do IPC with M4, it could not start, stop, update image.
>>>>
>>>> We disable recovery reboot when M4 is managed by SCFW, because
>>>> remoteproc core still not support M4 auto-recovery without loading
>>>> image.
>>>>
>>>> Signed-off-by: Peng Fan <peng.fan@....com>
>>>> ---
>>>>   drivers/remoteproc/imx_rproc.c | 108
>>>> ++++++++++++++++++++++++++++++++-
>>>>   1 file changed, 107 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/remoteproc/imx_rproc.c
>>>> b/drivers/remoteproc/imx_rproc.c index 7cc4fd207e2d..bcba74e90020
>>>> 100644
>>>> --- a/drivers/remoteproc/imx_rproc.c
>>>> +++ b/drivers/remoteproc/imx_rproc.c
>>>> @@ -6,6 +6,7 @@
>>>>   #include <linux/arm-smccc.h>
>>>>   #include <linux/clk.h>
>>>>   #include <linux/err.h>
>>>> +#include <linux/firmware/imx/sci.h>
>>>>   #include <linux/interrupt.h>
>>>>   #include <linux/kernel.h>
>>>>   #include <linux/mailbox_client.h>
>>>> @@ -59,6 +60,8 @@
>>>>   #define IMX_SIP_RPROC_STARTED		0x01
>>>>   #define IMX_SIP_RPROC_STOP		0x02
>>>>
>>>> +#define IMX_SC_IRQ_GROUP_REBOOTED	5
>>>> +
>>>>   /**
>>>>    * struct imx_rproc_mem - slim internal memory structure
>>>>    * @cpu_addr: MPU virtual address of the memory region @@ -89,6
>>>> +92,10 @@ struct imx_rproc {
>>>>   	struct work_struct		rproc_work;
>>>>   	struct workqueue_struct		*workqueue;
>>>>   	void __iomem			*rsc_table;
>>>> +	struct imx_sc_ipc		*ipc_handle;
>>>> +	struct notifier_block		rproc_nb;
>>>> +	u32				rproc_pt;	/* partition id */
>>>> +	u32				rsrc_id;	/* resource id */
>>>>   };
>>>>
>>>>   static const struct imx_rproc_att imx_rproc_att_imx93[] = { @@ -117,6
>>>> +124,18 @@ static const struct imx_rproc_att imx_rproc_att_imx93[] = {
>>>>   	{ 0xD0000000, 0xa0000000, 0x10000000, 0 },  };
>>>>
>>>> +static const struct imx_rproc_att imx_rproc_att_imx8qxp[] = {
>>>> +	{ 0x08000000, 0x08000000, 0x10000000, 0 },
>>>> +	/* TCML/U */
>>>> +	{ 0x1FFE0000, 0x34FE0000, 0x00040000, ATT_OWN | ATT_IOMEM },
>>>> +	/* OCRAM(Low 96KB) */
>>>> +	{ 0x21000000, 0x00100000, 0x00018000, 0 },
>>>> +	/* OCRAM */
>>>> +	{ 0x21100000, 0x00100000, 0x00040000, 0 },
>>>> +	/* DDR (Data) */
>>>> +	{ 0x80000000, 0x80000000, 0x60000000, 0 }, };
>>>> +
>>>>   static const struct imx_rproc_att imx_rproc_att_imx8mn[] = {
>>>>   	/* dev addr , sys addr  , size	    , flags */
>>>>   	/* ITCM   */
>>>> @@ -255,6 +274,12 @@ static const struct imx_rproc_dcfg
>>> imx_rproc_cfg_imx8mq = {
>>>>   	.method		= IMX_RPROC_MMIO,
>>>>   };
>>>>
>>>> +static const struct imx_rproc_dcfg imx_rproc_cfg_imx8qxp = {
>>>> +	.att		= imx_rproc_att_imx8qxp,
>>>> +	.att_size	= ARRAY_SIZE(imx_rproc_att_imx8qxp),
>>>> +	.method		= IMX_RPROC_SCU_API,
>>>> +};
>>>> +
>>>>   static const struct imx_rproc_dcfg imx_rproc_cfg_imx8ulp = {
>>>>   	.att		= imx_rproc_att_imx8ulp,
>>>>   	.att_size	= ARRAY_SIZE(imx_rproc_att_imx8ulp),
>>>> @@ -680,6 +705,37 @@ static void imx_rproc_free_mbox(struct rproc
>>> *rproc)
>>>>   	mbox_free_channel(priv->rx_ch);
>>>>   }
>>>>
>>>> +static void imx_rproc_put_scu(struct rproc *rproc) {
>>>> +	struct imx_rproc *priv = rproc->priv;
>>>> +	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
>>>> +
>>>> +	if (dcfg->method != IMX_RPROC_SCU_API)
>>>> +		return;
>>>> +
>>>> +	if (!imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
>>>> +		return;
>>>> +
>>>> +	imx_scu_irq_group_enable(IMX_SC_IRQ_GROUP_REBOOTED,
>>> BIT(priv->rproc_pt), false);
>>>> +	imx_scu_irq_unregister_notifier(&priv->rproc_nb);
>>>> +}
>>>> +
>>>> +static int imx_rproc_partition_notify(struct notifier_block *nb,
>>>> +				      unsigned long event, void *group) {
>>>> +	struct imx_rproc *priv = container_of(nb, struct imx_rproc,
>>>> +rproc_nb);
>>>> +
>>>> +	/* Ignore other irqs */
>>>> +	if (!((event & BIT(priv->rproc_pt)) && (*(u8 *)group ==
>>> IMX_SC_IRQ_GROUP_REBOOTED)))
>>>> +		return 0;
>>>> +
>>>> +	rproc_report_crash(priv->rproc, RPROC_WATCHDOG);
>>>> +
>>>> +	pr_info("Partition%d reset!\n", priv->rproc_pt);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>>   static int imx_rproc_detect_mode(struct imx_rproc *priv)  {
>>>>   	struct regmap_config config = { .name = "imx-rproc" }; @@ -689,6
>>>> +745,7 @@ static int imx_rproc_detect_mode(struct imx_rproc *priv)
>>>>   	struct arm_smccc_res res;
>>>>   	int ret;
>>>>   	u32 val;
>>>> +	u8 pt;
>>>>
>>>>   	switch (dcfg->method) {
>>>>   	case IMX_RPROC_NONE:
>>>> @@ -699,6 +756,51 @@ static int imx_rproc_detect_mode(struct
>>> imx_rproc *priv)
>>>>   		if (res.a0)
>>>>   			priv->rproc->state = RPROC_DETACHED;
>>>>   		return 0;
>>>> +	case IMX_RPROC_SCU_API:
>>>> +		ret = imx_scu_get_handle(&priv->ipc_handle);
>>>> +		if (ret)
>>>> +			return ret;
>>>> +		ret = of_property_read_u32(dev->of_node, "fsl,resource-id",
>>> &priv->rsrc_id);
>>>> +		if (ret) {
>>>> +			dev_err(dev, "No fsl,resource-id property\n");
>>>> +			return ret;
>>>> +		}
>>>> +
>>>> +		/*
>>>> +		 * If Mcore resource is not owned by Acore partition, It is
>>> kicked by ROM,
>>>> +		 * and Linux could only do IPC with Mcore and nothing else.
>>>> +		 */
>>>> +		if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv-
>>>> rsrc_id))
>>>> +			return 0;
>>>
>>> If imx_sc_rm_is_resource_owned() return '1' than the remote processor is
>>> under Linux's control and what follows below is not needed.  That is also
>>> coherent with the comment in [1].
>>
>> Case 1: If M4 is owned by Linux, here directly return 0.
>> Case 2: If M4 is not owned by Linux, the following code after this line will set
>> state as RPROC_DETACHED.
> 
> I understand that part.
> 
>>
>> Patch 3/6(this patch) is only to support case 2.
>> Patch 4/6 is to support case 1.
>>
> 
> Let's leave the subsequent patches alone for now.
> 
>>>
>>> That is in contrast with what is happening in imx_rproc_put_scu().  There, if
>>> the remote processor is _not_ owned by Linux than the condition returns
>>> without calling imx_scu_irq_group_enable() and
>>> imx_scu_irq_unregister_notifier().  That seems to be a bug.
>>
>> No. The two functions only needed when M4 is in a separate hardware partition.
>>
>> The scu irq is only needed when M4 is out of linux control and need some
>> notification such as M4 is reset by SCU(System Control Unit). That linux got
>> notification that M4 is reset by SCU.
> 
> I also understand that part.
> 
> What I am underlining here is that when the M4 is independent, function
> imx_scu_irq_register_notifier() and imx_scu_irq_group_enable() are called but
> their cleanup equivalent are not called in imx_rproc_put_scu() because of the '!'
> in the if() statement.

you are right, this is bug in my side. It should be as below based on 
patch 3/6.

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index bcba74e90020..a56aecae00c6 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -713,7 +713,7 @@ static void imx_rproc_put_scu(struct rproc *rproc)
         if (dcfg->method != IMX_RPROC_SCU_API)
                 return;

-       if (!imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
+       if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
                 return;

Thanks for detailed reviewing.

Thanks,
Peng.

> 
>>
>>>
>>> There is also a problem in patch 4/6 associated to that.
>>
>> If the upper explanation eliminate your concern, "a problem in patch 4/6" should
>> not be a problem.
>>
>> When M4 is owned by Linux, Linux need handle the power domain. If M4 is not owned
>> by Linux, SCU firmware will handle the power domain, and Linux has no permission to
>> touch that.
>>
>> Thanks
>> Peng
>>
>>>
>>> Thanks,
>>> Mathieu
>>>
>>>
>>> [1].
>>> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir
>>> .bootlin.com%2Flinux%2Fv6.0-
>>> rc7%2Fsource%2Fdrivers%2Ffirmware%2Fimx%2Frm.c%23L24&amp;data=0
>>> 5%7C01%7Cpeng.fan%40nxp.com%7Cbe679e9a409a48b834b908daa015d92
>>> c%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637998312946913
>>> 710%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2lu
>>> MzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=
>>> JDRvoDGGgEiSmbhj3410V2DNxamZbDmMS0U2GvBnI74%3D&amp;reserved
>>> =0
>>>
>>>> +
>>>> +		priv->rproc->state = RPROC_DETACHED;
>>>> +		priv->rproc->recovery_disabled = true;
>>>> +
>>>> +		/* Get partition id and enable irq in SCFW */
>>>> +		ret = imx_sc_rm_get_resource_owner(priv->ipc_handle,
>>> priv->rsrc_id, &pt);
>>>> +		if (ret) {
>>>> +			dev_err(dev, "not able to get resource owner\n");
>>>> +			return ret;
>>>> +		}
>>>> +
>>>> +		priv->rproc_pt = pt;
>>>> +		priv->rproc_nb.notifier_call = imx_rproc_partition_notify;
>>>> +
>>>> +		ret = imx_scu_irq_register_notifier(&priv->rproc_nb);
>>>> +		if (ret) {
>>>> +			dev_warn(dev, "register scu notifier failed.\n");
>>>> +			return ret;
>>>> +		}
>>>> +
>>>> +		ret =
>>> imx_scu_irq_group_enable(IMX_SC_IRQ_GROUP_REBOOTED, BIT(priv-
>>>> rproc_pt),
>>>> +					       true);
>>>> +		if (ret) {
>>>> +			imx_scu_irq_unregister_notifier(&priv->rproc_nb);
>>>> +			dev_warn(dev, "Enable irq failed.\n");
>>>> +			return ret;
>>>> +		}
>>>> +
>>>> +		return 0;
>>>>   	default:
>>>>   		break;
>>>>   	}
>>>> @@ -803,7 +905,7 @@ static int imx_rproc_probe(struct platform_device
>>>> *pdev)
>>>>
>>>>   	ret = imx_rproc_clk_enable(priv);
>>>>   	if (ret)
>>>> -		goto err_put_mbox;
>>>> +		goto err_put_scu;
>>>>
>>>>   	INIT_WORK(&priv->rproc_work, imx_rproc_vq_work);
>>>>
>>>> @@ -820,6 +922,8 @@ static int imx_rproc_probe(struct platform_device
>>>> *pdev)
>>>>
>>>>   err_put_clk:
>>>>   	clk_disable_unprepare(priv->clk);
>>>> +err_put_scu:
>>>> +	imx_rproc_put_scu(rproc);
>>>>   err_put_mbox:
>>>>   	imx_rproc_free_mbox(rproc);
>>>>   err_put_wkq:
>>>> @@ -837,6 +941,7 @@ static int imx_rproc_remove(struct
>>> platform_device
>>>> *pdev)
>>>>
>>>>   	clk_disable_unprepare(priv->clk);
>>>>   	rproc_del(rproc);
>>>> +	imx_rproc_put_scu(rproc);
>>>>   	imx_rproc_free_mbox(rproc);
>>>>   	destroy_workqueue(priv->workqueue);
>>>>   	rproc_free(rproc);
>>>> @@ -852,6 +957,7 @@ static const struct of_device_id
>>> imx_rproc_of_match[] = {
>>>>   	{ .compatible = "fsl,imx8mm-cm4", .data =
>>> &imx_rproc_cfg_imx8mq },
>>>>   	{ .compatible = "fsl,imx8mn-cm7", .data =
>>> &imx_rproc_cfg_imx8mn },
>>>>   	{ .compatible = "fsl,imx8mp-cm7", .data =
>>> &imx_rproc_cfg_imx8mn },
>>>> +	{ .compatible = "fsl,imx8qxp-cm4", .data =
>>> &imx_rproc_cfg_imx8qxp },
>>>>   	{ .compatible = "fsl,imx8ulp-cm33", .data =
>>> &imx_rproc_cfg_imx8ulp },
>>>>   	{ .compatible = "fsl,imx93-cm33", .data = &imx_rproc_cfg_imx93 },
>>>>   	{},
>>>> --
>>>> 2.37.1
>>>>

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