Subject: Re: [PATCH 6/9] remoteproc: imx_rproc: support attaching to i.MX8QXP M4

From: Mathieu Poirier <[email-masked]>
Date: Wed, 19 Jan 2022 11:04:13 -0700

On Wed, Jan 19, 2022 at 02:28:31AM +0000, Peng Fan wrote:
> > Subject: Re: [PATCH 6/9] remoteproc: imx_rproc: support attaching to
> > i.MX8QXP M4
> > 
> > On Tue, Jan 11, 2022 at 11:33:30AM +0800, Peng Fan (OSS) wrote:
> > > From: Peng Fan <[email-masked]>
> > >
> > > 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.
> > >
> > > When M4 crash reboot, it could notify Linux, so Linux could prepare to
> > > reattach to M4 after M4 recovery.
> > >
> > > Signed-off-by: Peng Fan <[email-masked]>
> > > ---
> > >  drivers/remoteproc/imx_rproc.c | 96
> > > ++++++++++++++++++++++++++++++++++
> > >  1 file changed, 96 insertions(+)
> > >
> > > diff --git a/drivers/remoteproc/imx_rproc.c
> > > b/drivers/remoteproc/imx_rproc.c index 0e99a3ca6fbc..5f04aea2f6a1
> > > 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 @@ -90,6
> > > +93,23 @@ struct imx_rproc {
> > >  	struct workqueue_struct		*workqueue;
> > >  	void __iomem			*rsc_table;
> > >  	bool				has_clk;
> > > +	struct imx_sc_ipc		*ipc_handle;
> > > +	struct notifier_block		proc_nb;
> > > +	u32				rproc_pt;
> > > +	u32				rsrc;
> > 
> > There is no documentation for the above two fields and I have to guess what
> > they do.
> 
> Fix in V2.
> 
> > 
> > > +};
> > > +
> > > +static const struct imx_rproc_att imx_rproc_att_imx8qxp[] = {
> > > +	/* dev addr , sys addr  , size	    , flags */
> > > +	{ 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[] = { @@
> > > -236,6 +256,12 @@ static const struct imx_rproc_dcfg
> > imx_rproc_cfg_imx8ulp = {
> > >  	.method		= IMX_RPROC_NONE,
> > >  };
> > >
> > > +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_imx7ulp = {
> > >  	.att		= imx_rproc_att_imx7ulp,
> > >  	.att_size	= ARRAY_SIZE(imx_rproc_att_imx7ulp),
> > > @@ -491,6 +517,11 @@ static int imx_rproc_attach(struct rproc *rproc)
> > >  	return 0;
> > >  }
> > >
> > > +static int imx_rproc_detach(struct rproc *rproc) {
> > > +	return 0;
> > 
> > Is it possible to detach the remote processor from the application core?  If
> > not please write a comment that says so.
> 
> No from my understanding.
> 
>   And shouldn't this return some
> > kind of error so that users don't think the operation was carried out
> > successfully?
> 
> No. This is to match patch 3/9 to support M-core self recovery. After M-core
> crash reboot, remoteproc framework just detach and re-attach.

Right, but by returning 0 in imx_rproc_detach() issueing something like:

        # echo detach > /sys/class/remoteproc/remoteproc0/state

will return without an error message, leading users to believe the remote
processor has been detached.  Returning an error code like -EINVAL would tell
users the operation was not completed successfully. 

More comments to come shortly...

> 
> > 
> > I am out of time for today and as such will continue with this set tomorrow.
> 
> Thanks for you reviewing the patchset.
> 
> Thanks,
> Peng.
> 
> > 
> > Thanks,
> > Mathieu
> > 
> > > +}
> > > +
> > >  static struct resource_table *imx_rproc_get_loaded_rsc_table(struct
> > > rproc *rproc, size_t *table_sz)  {
> > >  	struct imx_rproc *priv = rproc->priv; @@ -525,6 +556,7 @@
> > > imx_rproc_elf_find_loaded_rsc_table(struct rproc *rproc, const struct
> > > firmware *  static const struct rproc_ops imx_rproc_ops = {
> > >  	.prepare	= imx_rproc_prepare,
> > >  	.attach		= imx_rproc_attach,
> > > +	.detach		= imx_rproc_detach,
> > >  	.start		= imx_rproc_start,
> > >  	.stop		= imx_rproc_stop,
> > >  	.kick		= imx_rproc_kick,
> > > @@ -671,6 +703,22 @@ static void imx_rproc_free_mbox(struct rproc
> > *rproc)
> > >  	mbox_free_channel(priv->rx_ch);
> > >  }
> > >
> > > +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,
> > > +proc_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("Patition%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" }; @@ -680,6
> > > +728,7 @@ 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:
> > > @@ -690,6 +739,52 @@ 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, "rsrc-id", &priv->rsrc);
> > > +		if (ret) {
> > > +			dev_err(dev, "no rsrc-id\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)) {
> > > +
> > > +			priv->has_clk = false;
> > > +			priv->rproc->self_recovery = true;
> > > +			priv->rproc->state = RPROC_DETACHED;
> > > +
> > > +			/* Get partition id and enable irq in SCFW */
> > > +			ret = imx_sc_rm_get_resource_owner(priv->ipc_handle,
> > priv->rsrc, &pt);
> > > +			if (ret) {
> > > +				dev_err(dev, "not able to get resource owner\n");
> > > +				return ret;
> > > +			}
> > > +
> > > +			priv->rproc_pt = pt;
> > > +			priv->proc_nb.notifier_call = imx_rproc_partition_notify;
> > > +
> > > +			ret = imx_scu_irq_register_notifier(&priv->proc_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->proc_nb);
> > > +				dev_warn(dev, "Enable irq failed.\n");
> > > +				return ret;
> > > +			}
> > > +		}
> > > +
> > > +		return 0;
> > >  	default:
> > >  		break;
> > >  	}
> > > @@ -847,6 +942,7 @@ 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 },
> > >  	{},
> > >  };
> > > --
> > > 2.25.1
> > >

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