Re: [PATCH v2 2/3] remoteproc: imx_rproc: mailbox support

From: Mathieu Poirier
Date: Fri Apr 17 2020 - 12:02:15 EST


On Fri, 17 Apr 2020 at 02:38, Nikita Shubin <nikita.shubin@xxxxxxxxxxx> wrote:
>
> On Tue, 14 Apr 2020 11:20:05 -0600
> Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> wrote:
>
> > On Mon, Apr 06, 2020 at 02:33:09PM +0300, nikita.shubin@xxxxxxxxxxx
> > wrote:
> > > Add support for mailboxes to imx_rproc
> > >
> > > Signed-off-by: Nikita Shubin <NShubin@xxxxxxxxxx>
> > > ---
> > > drivers/remoteproc/Kconfig | 2 +
> > > drivers/remoteproc/imx_rproc.c | 142
> > > ++++++++++++++++++++++++++++++++- 2 files changed, 143
> > > insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> > > index 94afdde4bc9f..02d23a54c9cf 100644
> > > --- a/drivers/remoteproc/Kconfig
> > > +++ b/drivers/remoteproc/Kconfig
> > > @@ -17,6 +17,8 @@ if REMOTEPROC
> > > config IMX_REMOTEPROC
> > > tristate "IMX6/7 remoteproc support"
> > > depends on ARCH_MXC
> > > + select MAILBOX
> > > + select IMX_MBOX
> > > help
> > > Say y here to support iMX's remote processors (Cortex M4
> > > on iMX7D) via the remote processor framework.
> > > diff --git a/drivers/remoteproc/imx_rproc.c
> > > b/drivers/remoteproc/imx_rproc.c index bebc58d0f711..d2bede4ccb70
> > > 100644 --- a/drivers/remoteproc/imx_rproc.c
> > > +++ b/drivers/remoteproc/imx_rproc.c
> > > @@ -14,6 +14,9 @@
> > > #include <linux/platform_device.h>
> > > #include <linux/regmap.h>
> > > #include <linux/remoteproc.h>
> > > +#include <linux/mailbox_client.h>
> > > +
> > > +#include "remoteproc_internal.h"
> > >
> > > #define IMX7D_SRC_SCR 0x0C
> > > #define IMX7D_ENABLE_M4 BIT(3)
> > > @@ -47,6 +50,12 @@
> > >
> > > #define IMX_BOOT_PC 0x4
> > >
> > > +#define IMX_MBOX_NB_VQ 2
> > > +#define IMX_MBOX_NB_MBX 2
> >
> > Please align this.
> >
> > > +
> > > +#define IMX_MBX_VQ0 "vq0"
> > > +#define IMX_MBX_VQ1 "vq1"
> > > +
> > > /**
> > > * struct imx_rproc_mem - slim internal memory structure
> > > * @cpu_addr: MPU virtual address of the memory region
> > > @@ -80,6 +89,14 @@ struct imx_rproc_dcfg {
> > > size_t att_size;
> > > };
> > >
> > > +struct imx_mbox {
> > > + const unsigned char name[10];
> > > + struct mbox_chan *chan;
> > > + struct mbox_client client;
> > > + struct work_struct vq_work;
> > > + int vq_id;
> > > +};
> > > +
> > > struct imx_rproc {
> > > struct device *dev;
> > > struct regmap *regmap;
> > > @@ -88,6 +105,8 @@ struct imx_rproc {
> > > struct imx_rproc_mem
> > > mem[IMX7D_RPROC_MEM_MAX]; struct clk *clk;
> > > void __iomem *bootreg;
> > > + struct imx_mbox mb[IMX_MBOX_NB_MBX];
> > > + struct workqueue_struct *workqueue;
> > > };
> > >
> > > static const struct imx_rproc_att imx_rproc_att_imx7d[] = {
> > > @@ -251,10 +270,118 @@ static void *imx_rproc_da_to_va(struct rproc
> > > *rproc, u64 da, int len) return va;
> > > }
> > >
> > > +static void imx_rproc_mb_vq_work(struct work_struct *work)
> > > +{
> > > + struct imx_mbox *mb = container_of(work, struct imx_mbox,
> > > vq_work);
> > > + struct rproc *rproc = dev_get_drvdata(mb->client.dev);
> > > +
> > > + if (rproc_vq_interrupt(rproc, mb->vq_id) == IRQ_NONE)
> > > + dev_dbg(&rproc->dev, "no message found in vq%d\n",
> > > mb->vq_id); +}
> > > +
> > > +static void imx_rproc_mb_callback(struct mbox_client *cl, void
> > > *data) +{
> > > + struct rproc *rproc = dev_get_drvdata(cl->dev);
> > > + struct imx_mbox *mb = container_of(cl, struct imx_mbox,
> > > client);
> > > + struct imx_rproc *ddata = rproc->priv;
> > > +
> > > + queue_work(ddata->workqueue, &mb->vq_work);
> > > +}
> > > +
> > > +static const struct imx_mbox imx_rproc_mbox[IMX_MBOX_NB_MBX] = {
> > > + {
> > > + .name = IMX_MBX_VQ0,
> > > + .vq_id = 0,
> > > + .client = {
> > > + .rx_callback = imx_rproc_mb_callback,
> > > + .tx_block = false,
> > > + },
> > > + },
> > > + {
> > > + .name = IMX_MBX_VQ1,
> > > + .vq_id = 1,
> > > + .client = {
> > > + .rx_callback = imx_rproc_mb_callback,
> > > + .tx_block = false,
> > > + },
> > > + },
> > > +};
> > > +
> > > +static void imx_rproc_request_mbox(struct rproc *rproc)
> > > +{
> > > + struct imx_rproc *ddata = rproc->priv;
> > > + struct device *dev = &rproc->dev;
> > > + unsigned int i;
> > > + const unsigned char *name;
> > > + struct mbox_client *cl;
> > > +
> > > + /* Initialise mailbox structure table */
> > > + memcpy(ddata->mb, imx_rproc_mbox, sizeof(imx_rproc_mbox));
> > > +
> > > + for (i = 0; i < IMX_MBOX_NB_MBX; i++) {
> > > + name = ddata->mb[i].name;
> > > +
> > > + cl = &ddata->mb[i].client;
> > > + cl->dev = dev->parent;
> > > +
> > > + ddata->mb[i].chan =
> > > mbox_request_channel_byname(cl, name); +
> > > + dev_dbg(dev, "%s: name=%s, idx=%u\n",
> > > + __func__, name, ddata->mb[i].vq_id);
> > > +
> > > + if (IS_ERR(ddata->mb[i].chan)) {
> > > + dev_warn(dev, "cannot get %s mbox\n",
> > > name);
> > > + ddata->mb[i].chan = NULL;
> >
> > If the mailbox isn't ready this driver will fail without a chance of
> > recovery. Since most of the code in this patch is a carbon copy of
> > the implementation found in stm32_proc.c, I suggest you do the same
> > as they did in stm32_rproc_request_mbox() and privision for cases
> > where requesting a channel returns -EPROBE_DEFER.
> >
>
> Noted, will be fixed.
>
> > > + }
> > > +
> > > + if (ddata->mb[i].vq_id >= 0)
> > > + INIT_WORK(&ddata->mb[i].vq_work,
> > > imx_rproc_mb_vq_work);
> > > + }
> > > +}
> > > +
> > > +static void imx_rproc_free_mbox(struct rproc *rproc)
> > > +{
> > > + struct imx_rproc *ddata = rproc->priv;
> > > + unsigned int i;
> > > +
> > > + dev_dbg(&rproc->dev, "%s: %d boxes\n",
> > > + __func__, ARRAY_SIZE(ddata->mb));
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(ddata->mb); i++) {
> > > + if (ddata->mb[i].chan)
> > > + mbox_free_channel(ddata->mb[i].chan);
> > > + ddata->mb[i].chan = NULL;
> > > + }
> > > +}
> > > +
> > > +static void imx_rproc_kick(struct rproc *rproc, int vqid)
> > > +{
> > > + struct imx_rproc *ddata = rproc->priv;
> > > + unsigned int i;
> > > + int err;
> > > +
> > > + if (WARN_ON(vqid >= IMX_MBOX_NB_VQ))
> > > + return;
> > > +
> > > + for (i = 0; i < IMX_MBOX_NB_MBX; i++) {
> > > + if (vqid != ddata->mb[i].vq_id)
> > > + continue;
> > > + if (!ddata->mb[i].chan)
> > > + return;
> > > + dev_dbg(&rproc->dev, "sending message : vqid =
> > > %d\n", vqid);
> > > + err = mbox_send_message(ddata->mb[i].chan, &vqid);
> > > + if (err < 0)
> > > + dev_err(&rproc->dev, "%s: failed (%s,
> > > err:%d)\n",
> > > + __func__,
> > > ddata->mb[i].name, err);
> > > + return;
> > > + }
> > > +}
> > > +
> > > static const struct rproc_ops imx_rproc_ops = {
> > > .start = imx_rproc_start,
> > > .stop = imx_rproc_stop,
> > > .da_to_va = imx_rproc_da_to_va,
> > > + .kick = imx_rproc_kick,
> > > .get_boot_addr = rproc_elf_get_boot_addr,
> > > };
> > >
> > > @@ -384,14 +511,26 @@ static int imx_rproc_probe(struct
> > > platform_device *pdev) goto err_put_rproc;
> > > }
> > >
> > > + priv->workqueue = create_workqueue(dev_name(dev));
> > > + if (!priv->workqueue) {
> > > + dev_err(dev, "cannot create workqueue\n");
> > > + ret = -ENOMEM;
> > > + goto err_put_clk;
> > > + }
> > > +
> > > + imx_rproc_request_mbox(rproc);
> > > +
> > > ret = rproc_add(rproc);
> > > if (ret) {
> > > dev_err(dev, "rproc_add failed\n");
> > > - goto err_put_clk;
> > > + goto err_free_mb;
> > > }
> > >
> > > return 0;
> > >
> > > +err_free_mb:
> > > + imx_rproc_free_mbox(rproc);
> > > + destroy_workqueue(priv->workqueue);
> > > err_put_clk:
> > > clk_disable_unprepare(priv->clk);
> > > err_put_rproc:
> > > @@ -407,6 +546,7 @@ static int imx_rproc_remove(struct
> > > platform_device *pdev)
> > > clk_disable_unprepare(priv->clk);
> > > rproc_del(rproc);
> > > + imx_rproc_free_mbox(rproc);
> >
> > I have no issues with people reusing code already found in the kernel
> > - in fact I encourage it because it makes reviewing patches much
> > easier. On the flip side you have to give credit where it is due.
> > Here adding a line in the changelog that mentions where you took your
> > inspiration from will be much appreciated.
>
> Please don't blame on things i never did citing my own self from 0/0:

I am not blaming you at all.

>
> | Regarding mailboxes and memory regions :
>
> | This code is heavily derived from stm32-rproc (i.e. copy pasted) and
> | this fact needs to reflected in commits, please tell me how to
> | emphasize this fact.
>
> I am eager to give credits.

I didn't notice that in the original cover letter. In the changelog,
between the description of the work and the signed-off-by and on a
line on its own, simply write that "the work is inspired from the
STM32 platform driver (drivers/remoteproc/stm32_rproc.c)".

>
>
> >
> > Thanks,
> > Mathieu
> >
> > > rproc_free(rproc);
> > >
> > > return 0;
> > > --
> > > 2.25.1
> > >
>