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Date:   Wed, 28 Sep 2022 11:30:54 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     Peng Fan <peng.fan@oss.nxp.com>
Cc:     Peng Fan <peng.fan@nxp.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "krzysztof.kozlowski+dt@linaro.org" 
        <krzysztof.kozlowski+dt@linaro.org>,
        "shawnguo@kernel.org" <shawnguo@kernel.org>,
        "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
        "kernel@pengutronix.de" <kernel@pengutronix.de>,
        "festevam@gmail.com" <festevam@gmail.com>,
        dl-linux-imx <linux-imx@nxp.com>,
        "linux-remoteproc@vger.kernel.org" <linux-remoteproc@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Bjorn Andersson <andersson@kernel.org>
Subject: Re: [PATCH V5 3/6] remoteproc: imx_rproc: support attaching to
 i.MX8QXP M4
Message-ID: <20220928173054.GC2990524@p14s>
References: <20220824011023.1493050-1-peng.fan@oss.nxp.com>
 <20220824011023.1493050-4-peng.fan@oss.nxp.com>
 <20220926232127.GB2817947@p14s>
 <DU0PR04MB9417EABB1B0A9B550E94236288559@DU0PR04MB9417.eurprd04.prod.outlook.com>
 <20220927175649.GB2883698@p14s>
 <64c6bdc2-583d-a2d0-f8b8-c4487f8a4d97@oss.nxp.com>
 <65b7224d-d3eb-4513-d733-ec781864fb7b@oss.nxp.com>
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On Wed, Sep 28, 2022 at 06:01:45PM +0800, Peng Fan wrote:
> Hi Mathieu,
> 
> On 9/28/2022 3:39 PM, Peng Fan wrote:
> > 
> > 
> > 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@nxp.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@nxp.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))

Indeed, which raises questions about how this patchset was tested.  And it is
not the first time we touch base on that.

> >  ??????????????? return;
> > 
> > Thanks for detailed reviewing.
> 
> If you are fine with this change, I could send out V6. Anyway, I'll wait
> to see if you have other comments in this patchset.
>

I am out of time for this patchset and as such will not provide more comments
on this revision.

> Thanks,
> Peng.
> 
> > 
> > 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
> > > > > >