RE: [PATCH V3 5/6] remoteproc: imx_rproc: support i.MX8QM

From: Peng Fan
Date: Tue Jun 28 2022 - 21:19:43 EST


> Subject: Re: [PATCH V3 5/6] remoteproc: imx_rproc: support i.MX8QM
>
> On Tue, May 17, 2022 at 02:49:36PM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > Most logic are same as i.MX8QXP, but i.MX8QM has two general purpose
> > M4 cores, the two cores runs independently and they has different
> > resource id, different start address from SCFW view.
> >
> > Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> > ---
> > drivers/remoteproc/imx_rproc.c | 41
> > +++++++++++++++++++++++++++++++---
> > 1 file changed, 38 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/remoteproc/imx_rproc.c
> > b/drivers/remoteproc/imx_rproc.c index 49cce9dd55c7..8326193c13d6
> > 100644
> > --- a/drivers/remoteproc/imx_rproc.c
> > +++ b/drivers/remoteproc/imx_rproc.c
> > @@ -3,6 +3,7 @@
> > * Copyright (c) 2017 Pengutronix, Oleksij Rempel
> <kernel@xxxxxxxxxxxxxx>
> > */
> >
> > +#include <dt-bindings/firmware/imx/rsrc.h>
> > #include <linux/arm-smccc.h>
> > #include <linux/clk.h>
> > #include <linux/err.h>
> > @@ -75,10 +76,13 @@ struct imx_rproc_mem {
> > size_t size;
> > };
> >
> > -/* att flags */
> > +/* att flags: lower 16 bits specifying core, higher 16 bits for flags
> > +*/
> > /* M4 own area. Can be mapped at probe */
> > -#define ATT_OWN BIT(1)
> > -#define ATT_IOMEM BIT(2)
> > +#define ATT_OWN BIT(31)
> > +#define ATT_IOMEM BIT(30)
> > +
> > +#define ATT_CORE_MASK 0xffff
> > +#define ATT_CORE(I) BIT((I))
> >
> > struct imx_rproc {
> > struct device *dev;
> > @@ -99,6 +103,7 @@ struct imx_rproc {
> > u32 rsrc_id; /* resource id */
> > u32 entry; /* cpu start address */
> > int num_pd;
> > + u32 core_index;
> > struct device **pd_dev;
> > struct device_link **pd_dev_link;
> > };
> > @@ -129,6 +134,19 @@ static const struct imx_rproc_att
> imx_rproc_att_imx93[] = {
> > { 0xD0000000, 0xa0000000, 0x10000000, 0 }, };
> >
> > +static const struct imx_rproc_att imx_rproc_att_imx8qm[] = {
> > + /* dev addr , sys addr , size , flags */
> > + { 0x08000000, 0x08000000, 0x10000000, 0},
> > + /* TCML */
> > + { 0x1FFE0000, 0x34FE0000, 0x00020000, ATT_OWN | ATT_IOMEM |
> ATT_CORE(0)},
> > + { 0x1FFE0000, 0x38FE0000, 0x00020000, ATT_OWN | ATT_IOMEM |
> ATT_CORE(1)},
> > + /* TCMU */
> > + { 0x20000000, 0x35000000, 0x00020000, ATT_OWN | ATT_IOMEM |
> ATT_CORE(0)},
> > + { 0x20000000, 0x39000000, 0x00020000, ATT_OWN | ATT_IOMEM |
> ATT_CORE(1)},
> > + /* DDR (Data) */
> > + { 0x80000000, 0x80000000, 0x60000000, 0 }, };
> > +
> > static const struct imx_rproc_att imx_rproc_att_imx8qxp[] = {
> > { 0x08000000, 0x08000000, 0x10000000, 0 },
> > /* TCML/U */
> > @@ -279,6 +297,12 @@ static const struct imx_rproc_dcfg
> imx_rproc_cfg_imx8mq = {
> > .method = IMX_RPROC_MMIO,
> > };
> >
> > +static const struct imx_rproc_dcfg imx_rproc_cfg_imx8qm = {
> > + .att = imx_rproc_att_imx8qm,
> > + .att_size = ARRAY_SIZE(imx_rproc_att_imx8qm),
> > + .method = IMX_RPROC_SCU_API,
> > +};
> > +
> > static const struct imx_rproc_dcfg imx_rproc_cfg_imx8qxp = {
> > .att = imx_rproc_att_imx8qxp,
> > .att_size = ARRAY_SIZE(imx_rproc_att_imx8qxp),
> > @@ -395,6 +419,11 @@ static int imx_rproc_da_to_sys(struct imx_rproc
> *priv, u64 da,
> > for (i = 0; i < dcfg->att_size; i++) {
> > const struct imx_rproc_att *att = &dcfg->att[i];
> >
> > + if (att->flags & ATT_CORE_MASK) {
> > + if (!((BIT(priv->core_index)) & (att->flags & ATT_CORE_MASK)))
> > + continue;
> > + }
>
> This is very cryptic - I just spent 20 minutes looking at it and I'm still not sure I
> got the full meaning. Please add enough comments to make things obvious
> on first read.

There are two generic M4 cores in i.MX8QM, so core_index is 0 for M4_0,
and 1 for M4_1.

In the memory mapping array:
{ 0x1FFE0000, 0x34FE0000, 0x00020000, ATT_OWN | ATT_IOMEM | ATT_CORE(0)},
{ 0x1FFE0000, 0x38FE0000, 0x00020000, ATT_OWN | ATT_IOMEM | ATT_CORE(1)},
/* TCMU */
{ 0x20000000, 0x35000000, 0x00020000, ATT_OWN | ATT_IOMEM | ATT_CORE(0)},
{ 0x20000000, 0x39000000, 0x00020000, ATT_OWN | ATT_IOMEM | ATT_CORE(1)},

ATT_CORE(0) means it is for M4_0, ATT_CORE(1) for M4_1.

Back to this piece code:
if (att->flags & ATT_CORE_MASK) {
if (!((BIT(priv->core_index)) & (att->flags & ATT_CORE_MASK)))
continue;
}

Taking M4_1 for example, priv->core_index is 1. So when it need translate an address with
ATT_CORE(X) flag, it should ignore ATT_CORE(0) entries. Hope this is clear. For adding
comments, how do you think:

/* Bypass the entries that not belong to the current remote core */

Thanks,
Peng.

>
> I am done reviewing this patchset.
>
> Thanks,
> Mathieu
>
>
> > +
> > if (da >= att->da && da + len < att->da + att->size) {
> > unsigned int offset = da - att->da;
> >
> > @@ -815,6 +844,11 @@ static int imx_rproc_detect_mode(struct
> imx_rproc *priv)
> > return ret;
> > }
> >
> > + if (priv->rsrc_id == IMX_SC_R_M4_1_PID0)
> > + priv->core_index = 1;
> > + else
> > + priv->core_index = 0;
> > +
> > /*
> > * 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.
> > @@ -1008,6 +1042,7 @@ static const struct of_device_id
> imx_rproc_of_match[] = {
> > { .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,imx8qm-cm4", .data = &imx_rproc_cfg_imx8qm },
> > { .compatible = "fsl,imx8ulp-cm33", .data = &imx_rproc_cfg_imx8ulp },
> > { .compatible = "fsl,imx93-cm33", .data = &imx_rproc_cfg_imx93 },
> > {},
> > --
> > 2.25.1
> >