2023-07-07 05:28:37

by Tinghan Shen

Subject: [PATCH v14 07/12] remoteproc: mediatek: Remove dependency of MT8195 SCP L2TCM power control on dual-core SCP

Previously, SCP core 0 controlled the power of L2TCM and dictated that
SCP core 1 could only boot after SCP core 0. To address this constraint,
extracted the power control flow of L2TCM and made it shared
between both cores, enabling support of arbitrary boot order.

The flow for controlling L2TCM power has been incorporated into the
mt8195_scp_before_load() and mt8195_scp_stop() APIs, which are
respectively invoked during the rproc->ops->start() and
rproc->ops->stop() operations. These APIs effectively serve the same
purpose as the rproc prepare()/unprepare() APIs."

Signed-off-by: Tinghan Shen <[email protected]>
---
drivers/remoteproc/mtk_common.h | 1 +
drivers/remoteproc/mtk_scp.c | 80 ++++++++++++++++++++++++++-------
2 files changed, 66 insertions(+), 15 deletions(-)

diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
index 56395e8664cb..41e1b4732b75 100644
--- a/drivers/remoteproc/mtk_common.h
+++ b/drivers/remoteproc/mtk_common.h
@@ -130,6 +130,7 @@ struct mtk_scp {
struct rproc_subdev *rpmsg_subdev;

struct list_head elem;
+ struct platform_device *cluster_pdev;
};

/**
diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index 3349488e5f21..94602272c05f 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -29,6 +29,10 @@ struct mtk_scp_of_cluster {
size_t l1tcm_size;
phys_addr_t l1tcm_phys;
struct list_head mtk_scp_list;
+
+ /* Prevent concurrent operations of L2TCM power control. */
+ struct mutex l2tcm_lock;
+ u32 l2tcm_refcnt;
};

/**
@@ -449,7 +453,7 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)

writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);

- /* enable SRAM clock */
+ /* enable SRAM power */
scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
@@ -462,19 +466,38 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
return 0;
}

-static int mt8195_scp_before_load(struct mtk_scp *scp)
+static int mt8195_scp_l2tcm_on(struct mtk_scp *scp)
{
- /* clear SPM interrupt, SCP2SPM_IPC_CLR */
- writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
+ struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
+
+ mutex_lock(&scp_cluster->l2tcm_lock);
+
+ if (scp_cluster->l2tcm_refcnt == 0) {
+ /* clear SPM interrupt, SCP2SPM_IPC_CLR */
+ writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
+
+ /* Power on L2TCM */
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
+ MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
+ }
+
+ scp_cluster->l2tcm_refcnt += 1;

+ mutex_unlock(&scp_cluster->l2tcm_lock);
+
+ return 0;
+}
+
+static int mt8195_scp_before_load(struct mtk_scp *scp)
+{
writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);

+ mt8195_scp_l2tcm_on(scp);
+
/* enable SRAM clock */
- scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
- scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
- scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
- scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
- MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);

/* enable MPU for all memory regions */
@@ -487,6 +510,8 @@ static int mt8195_scp_c1_before_load(struct mtk_scp *scp)
{
scp->data->scp_reset_assert(scp);

+ mt8195_scp_l2tcm_on(scp);
+
scp_sram_power_on(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);

/* enable MPU for all memory regions */
@@ -653,14 +678,30 @@ static void mt8192_scp_stop(struct mtk_scp *scp)
writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
}

+static void mt8195_scp_l2tcm_off(struct mtk_scp *scp)
+{
+ struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
+
+ mutex_lock(&scp_cluster->l2tcm_lock);
+
+ scp_cluster->l2tcm_refcnt -= 1;
+
+ if (scp_cluster->l2tcm_refcnt == 0) {
+ /* Power off L2TCM */
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
+ }
+
+ mutex_unlock(&scp_cluster->l2tcm_lock);
+}
+
static void mt8195_scp_stop(struct mtk_scp *scp)
{
- /* Disable SRAM clock */
- scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
- scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
- scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
- scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
- MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
+ mt8195_scp_l2tcm_off(scp);
+
scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);

/* Disable SCP watchdog */
@@ -669,6 +710,8 @@ static void mt8195_scp_stop(struct mtk_scp *scp)

static void mt8195_scp_c1_stop(struct mtk_scp *scp)
{
+ mt8195_scp_l2tcm_off(scp);
+
/* Power off CPU SRAM */
scp_sram_power_off(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);

@@ -976,6 +1019,8 @@ static int scp_add_single_core(struct platform_device *pdev)
if (IS_ERR(scp))
return PTR_ERR(scp);

+ scp->cluster_pdev = pdev;
+
ret = rproc_add(scp->rproc);
if (ret) {
dev_err(dev, "Failed to add rproc\n");
@@ -1028,6 +1073,8 @@ static int scp_add_multi_core(struct platform_device *pdev)
goto init_fail;
}

+ scp->cluster_pdev = pdev;
+
ret = rproc_add(scp->rproc);
if (ret) {
dev_err(dev, "Failed to add rproc of core %d\n", core_id);
@@ -1114,6 +1161,7 @@ static int scp_probe(struct platform_device *pdev)
}

INIT_LIST_HEAD(&scp_cluster->mtk_scp_list);
+ mutex_init(&scp_cluster->l2tcm_lock);
platform_set_drvdata(pdev, scp_cluster);

ret = devm_of_platform_populate(dev);
@@ -1137,6 +1185,8 @@ static void scp_remove(struct platform_device *pdev)
rproc_del(scp->rproc);
scp_free(scp);
}
+
+ mutex_destroy(&scp_cluster->l2tcm_lock);
}

static const struct mtk_scp_of_data mt8183_of_data = {
--
2.18.0

2023-07-11 18:12:11

by Mathieu Poirier

Subject: Re: [PATCH v14 07/12] remoteproc: mediatek: Remove dependency of MT8195 SCP L2TCM power control on dual-core SCP

On Tue, Jul 11, 2023 at 11:50:03AM -0600, Mathieu Poirier wrote:
> On Fri, Jul 07, 2023 at 01:26:07PM +0800, Tinghan Shen wrote:
> > Previously, SCP core 0 controlled the power of L2TCM and dictated that
> > SCP core 1 could only boot after SCP core 0. To address this constraint,
> > extracted the power control flow of L2TCM and made it shared
> > between both cores, enabling support of arbitrary boot order.
>
> Definitely an improvement.
>
> >
> > The flow for controlling L2TCM power has been incorporated into the
> > mt8195_scp_before_load() and mt8195_scp_stop() APIs, which are
> > respectively invoked during the rproc->ops->start() and
> > rproc->ops->stop() operations. These APIs effectively serve the same
> > purpose as the rproc prepare()/unprepare() APIs."
>
> I'm not fond of that custom API but it is so widespread in this driver that I
> will go with it.
>
> >
> > Signed-off-by: Tinghan Shen <[email protected]>
> > ---
> > drivers/remoteproc/mtk_common.h | 1 +
> > drivers/remoteproc/mtk_scp.c | 80 ++++++++++++++++++++++++++-------
> > 2 files changed, 66 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
> > index 56395e8664cb..41e1b4732b75 100644
> > --- a/drivers/remoteproc/mtk_common.h
> > +++ b/drivers/remoteproc/mtk_common.h
> > @@ -130,6 +130,7 @@ struct mtk_scp {
> > struct rproc_subdev *rpmsg_subdev;
> >
> > struct list_head elem;
> > + struct platform_device *cluster_pdev;
>
> This isn't needed. rproc->dev.parent is pdev->dev. Use container_of() to
> get to the platform device.
>
>
> > };
> >
> > /**
> > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> > index 3349488e5f21..94602272c05f 100644
> > --- a/drivers/remoteproc/mtk_scp.c
> > +++ b/drivers/remoteproc/mtk_scp.c
> > @@ -29,6 +29,10 @@ struct mtk_scp_of_cluster {
> > size_t l1tcm_size;
> > phys_addr_t l1tcm_phys;
> > struct list_head mtk_scp_list;
> > +
> > + /* Prevent concurrent operations of L2TCM power control. */
> > + struct mutex l2tcm_lock;
> > + u32 l2tcm_refcnt;
> > };
> >
> > /**
> > @@ -449,7 +453,7 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
> >
> > writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
> >
> > - /* enable SRAM clock */
> > + /* enable SRAM power */
> > scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > @@ -462,19 +466,38 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
> > return 0;
> > }
> >
> > -static int mt8195_scp_before_load(struct mtk_scp *scp)
> > +static int mt8195_scp_l2tcm_on(struct mtk_scp *scp)
> > {
> > - /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> > - writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> > + struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
> > +
> > + mutex_lock(&scp_cluster->l2tcm_lock);
> > +
> > + if (scp_cluster->l2tcm_refcnt == 0) {
> > + /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> > + writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> > +
> > + /* Power on L2TCM */
> > + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > + scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> > + MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> > + }
> > +
> > + scp_cluster->l2tcm_refcnt += 1;
> >
> > + mutex_unlock(&scp_cluster->l2tcm_lock);
> > +
> > + return 0;
> > +}
> > +
> > +static int mt8195_scp_before_load(struct mtk_scp *scp)
> > +{
> > writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
> >
> > + mt8195_scp_l2tcm_on(scp);
> > +
> > /* enable SRAM clock */
> > - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > - scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> > - MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> > scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> >
> > /* enable MPU for all memory regions */
> > @@ -487,6 +510,8 @@ static int mt8195_scp_c1_before_load(struct mtk_scp *scp)
> > {
> > scp->data->scp_reset_assert(scp);
> >
> > + mt8195_scp_l2tcm_on(scp);
> > +
> > scp_sram_power_on(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);
> >
> > /* enable MPU for all memory regions */
> > @@ -653,14 +678,30 @@ static void mt8192_scp_stop(struct mtk_scp *scp)
> > writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
> > }
> >
> > +static void mt8195_scp_l2tcm_off(struct mtk_scp *scp)
> > +{
> > + struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
> > +
> > + mutex_lock(&scp_cluster->l2tcm_lock);
> > +
>
> What happens if ->l2tcm_refcnt is 0 and this function is called?
>

More comments to come tomorrow.

Thanks,
Mathieu

>
> > + scp_cluster->l2tcm_refcnt -= 1;
> > +
> > + if (scp_cluster->l2tcm_refcnt == 0) {
> > + /* Power off L2TCM */
> > + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> > + }
> > +
> > + mutex_unlock(&scp_cluster->l2tcm_lock);
> > +}
> > +
> > static void mt8195_scp_stop(struct mtk_scp *scp)
> > {
> > - /* Disable SRAM clock */
> > - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > - scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> > - MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> > + mt8195_scp_l2tcm_off(scp);
> > +
> > scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> >
> > /* Disable SCP watchdog */
> > @@ -669,6 +710,8 @@ static void mt8195_scp_stop(struct mtk_scp *scp)
> >
> > static void mt8195_scp_c1_stop(struct mtk_scp *scp)
> > {
> > + mt8195_scp_l2tcm_off(scp);
> > +
> > /* Power off CPU SRAM */
> > scp_sram_power_off(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);
> >
> > @@ -976,6 +1019,8 @@ static int scp_add_single_core(struct platform_device *pdev)
> > if (IS_ERR(scp))
> > return PTR_ERR(scp);
> >
> > + scp->cluster_pdev = pdev;
> > +
> > ret = rproc_add(scp->rproc);
> > if (ret) {
> > dev_err(dev, "Failed to add rproc\n");
> > @@ -1028,6 +1073,8 @@ static int scp_add_multi_core(struct platform_device *pdev)
> > goto init_fail;
> > }
> >
> > + scp->cluster_pdev = pdev;
> > +
> > ret = rproc_add(scp->rproc);
> > if (ret) {
> > dev_err(dev, "Failed to add rproc of core %d\n", core_id);
> > @@ -1114,6 +1161,7 @@ static int scp_probe(struct platform_device *pdev)
> > }
> >
> > INIT_LIST_HEAD(&scp_cluster->mtk_scp_list);
> > + mutex_init(&scp_cluster->l2tcm_lock);
> > platform_set_drvdata(pdev, scp_cluster);
> >
> > ret = devm_of_platform_populate(dev);
> > @@ -1137,6 +1185,8 @@ static void scp_remove(struct platform_device *pdev)
> > rproc_del(scp->rproc);
> > scp_free(scp);
> > }
> > +
> > + mutex_destroy(&scp_cluster->l2tcm_lock);
> > }
> >
> > static const struct mtk_scp_of_data mt8183_of_data = {
> > --
> > 2.18.0
> >

2023-07-11 18:16:06

by Mathieu Poirier

Subject: Re: [PATCH v14 07/12] remoteproc: mediatek: Remove dependency of MT8195 SCP L2TCM power control on dual-core SCP

On Fri, Jul 07, 2023 at 01:26:07PM +0800, Tinghan Shen wrote:
> Previously, SCP core 0 controlled the power of L2TCM and dictated that
> SCP core 1 could only boot after SCP core 0. To address this constraint,
> extracted the power control flow of L2TCM and made it shared
> between both cores, enabling support of arbitrary boot order.

Definitely an improvement.

>
> The flow for controlling L2TCM power has been incorporated into the
> mt8195_scp_before_load() and mt8195_scp_stop() APIs, which are
> respectively invoked during the rproc->ops->start() and
> rproc->ops->stop() operations. These APIs effectively serve the same
> purpose as the rproc prepare()/unprepare() APIs."

I'm not fond of that custom API but it is so widespread in this driver that I
will go with it.

>
> Signed-off-by: Tinghan Shen <[email protected]>
> ---
> drivers/remoteproc/mtk_common.h | 1 +
> drivers/remoteproc/mtk_scp.c | 80 ++++++++++++++++++++++++++-------
> 2 files changed, 66 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
> index 56395e8664cb..41e1b4732b75 100644
> --- a/drivers/remoteproc/mtk_common.h
> +++ b/drivers/remoteproc/mtk_common.h
> @@ -130,6 +130,7 @@ struct mtk_scp {
> struct rproc_subdev *rpmsg_subdev;
>
> struct list_head elem;
> + struct platform_device *cluster_pdev;

This isn't needed. rproc->dev.parent is pdev->dev. Use container_of() to
get to the platform device.


> };
>
> /**
> diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> index 3349488e5f21..94602272c05f 100644
> --- a/drivers/remoteproc/mtk_scp.c
> +++ b/drivers/remoteproc/mtk_scp.c
> @@ -29,6 +29,10 @@ struct mtk_scp_of_cluster {
> size_t l1tcm_size;
> phys_addr_t l1tcm_phys;
> struct list_head mtk_scp_list;
> +
> + /* Prevent concurrent operations of L2TCM power control. */
> + struct mutex l2tcm_lock;
> + u32 l2tcm_refcnt;
> };
>
> /**
> @@ -449,7 +453,7 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
>
> writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
>
> - /* enable SRAM clock */
> + /* enable SRAM power */
> scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> @@ -462,19 +466,38 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
> return 0;
> }
>
> -static int mt8195_scp_before_load(struct mtk_scp *scp)
> +static int mt8195_scp_l2tcm_on(struct mtk_scp *scp)
> {
> - /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> - writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> + struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
> +
> + mutex_lock(&scp_cluster->l2tcm_lock);
> +
> + if (scp_cluster->l2tcm_refcnt == 0) {
> + /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> + writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> +
> + /* Power on L2TCM */
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> + scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> + MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> + }
> +
> + scp_cluster->l2tcm_refcnt += 1;
>
> + mutex_unlock(&scp_cluster->l2tcm_lock);
> +
> + return 0;
> +}
> +
> +static int mt8195_scp_before_load(struct mtk_scp *scp)
> +{
> writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
>
> + mt8195_scp_l2tcm_on(scp);
> +
> /* enable SRAM clock */
> - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> - scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> - MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
>
> /* enable MPU for all memory regions */
> @@ -487,6 +510,8 @@ static int mt8195_scp_c1_before_load(struct mtk_scp *scp)
> {
> scp->data->scp_reset_assert(scp);
>
> + mt8195_scp_l2tcm_on(scp);
> +
> scp_sram_power_on(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);
>
> /* enable MPU for all memory regions */
> @@ -653,14 +678,30 @@ static void mt8192_scp_stop(struct mtk_scp *scp)
> writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
> }
>
> +static void mt8195_scp_l2tcm_off(struct mtk_scp *scp)
> +{
> + struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
> +
> + mutex_lock(&scp_cluster->l2tcm_lock);
> +

What happens if ->l2tcm_refcnt is 0 and this function is called?


> + scp_cluster->l2tcm_refcnt -= 1;
> +
> + if (scp_cluster->l2tcm_refcnt == 0) {
> + /* Power off L2TCM */
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
> + scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> + }
> +
> + mutex_unlock(&scp_cluster->l2tcm_lock);
> +}
> +
> static void mt8195_scp_stop(struct mtk_scp *scp)
> {
> - /* Disable SRAM clock */
> - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> - scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> - MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> + mt8195_scp_l2tcm_off(scp);
> +
> scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
>
> /* Disable SCP watchdog */
> @@ -669,6 +710,8 @@ static void mt8195_scp_stop(struct mtk_scp *scp)
>
> static void mt8195_scp_c1_stop(struct mtk_scp *scp)
> {
> + mt8195_scp_l2tcm_off(scp);
> +
> /* Power off CPU SRAM */
> scp_sram_power_off(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);
>
> @@ -976,6 +1019,8 @@ static int scp_add_single_core(struct platform_device *pdev)
> if (IS_ERR(scp))
> return PTR_ERR(scp);
>
> + scp->cluster_pdev = pdev;
> +
> ret = rproc_add(scp->rproc);
> if (ret) {
> dev_err(dev, "Failed to add rproc\n");
> @@ -1028,6 +1073,8 @@ static int scp_add_multi_core(struct platform_device *pdev)
> goto init_fail;
> }
>
> + scp->cluster_pdev = pdev;
> +
> ret = rproc_add(scp->rproc);
> if (ret) {
> dev_err(dev, "Failed to add rproc of core %d\n", core_id);
> @@ -1114,6 +1161,7 @@ static int scp_probe(struct platform_device *pdev)
> }
>
> INIT_LIST_HEAD(&scp_cluster->mtk_scp_list);
> + mutex_init(&scp_cluster->l2tcm_lock);
> platform_set_drvdata(pdev, scp_cluster);
>
> ret = devm_of_platform_populate(dev);
> @@ -1137,6 +1185,8 @@ static void scp_remove(struct platform_device *pdev)
> rproc_del(scp->rproc);
> scp_free(scp);
> }
> +
> + mutex_destroy(&scp_cluster->l2tcm_lock);
> }
>
> static const struct mtk_scp_of_data mt8183_of_data = {
> --
> 2.18.0
>

2023-07-13 07:59:11

by Tinghan Shen

Subject: Re: [PATCH v14 07/12] remoteproc: mediatek: Remove dependency of MT8195 SCP L2TCM power control on dual-core SCP

Hi Mathieu,

On Tue, 2023-07-11 at 11:50 -0600, Mathieu Poirier wrote:
> On Fri, Jul 07, 2023 at 01:26:07PM +0800, Tinghan Shen wrote:
> > Previously, SCP core 0 controlled the power of L2TCM and dictated that
> > SCP core 1 could only boot after SCP core 0. To address this constraint,
> > extracted the power control flow of L2TCM and made it shared
> > between both cores, enabling support of arbitrary boot order.
>
> Definitely an improvement.
>
> >
> > The flow for controlling L2TCM power has been incorporated into the
> > mt8195_scp_before_load() and mt8195_scp_stop() APIs, which are
> > respectively invoked during the rproc->ops->start() and
> > rproc->ops->stop() operations. These APIs effectively serve the same
> > purpose as the rproc prepare()/unprepare() APIs."
>
> I'm not fond of that custom API but it is so widespread in this driver that I
> will go with it.
>
> >
> > Signed-off-by: Tinghan Shen <[email protected]>
> > ---
> > drivers/remoteproc/mtk_common.h | 1 +
> > drivers/remoteproc/mtk_scp.c | 80 ++++++++++++++++++++++++++-------
> > 2 files changed, 66 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
> > index 56395e8664cb..41e1b4732b75 100644
> > --- a/drivers/remoteproc/mtk_common.h
> > +++ b/drivers/remoteproc/mtk_common.h
> > @@ -130,6 +130,7 @@ struct mtk_scp {
> > struct rproc_subdev *rpmsg_subdev;
> >
> > struct list_head elem;
> > + struct platform_device *cluster_pdev;
>
> This isn't needed. rproc->dev.parent is pdev->dev. Use container_of() to
> get to the platform device.

Ok, I'll update it in the next version.

>
>
> > };
> >
> > /**
> > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> > index 3349488e5f21..94602272c05f 100644
> > --- a/drivers/remoteproc/mtk_scp.c
> > +++ b/drivers/remoteproc/mtk_scp.c
> > @@ -29,6 +29,10 @@ struct mtk_scp_of_cluster {
> > size_t l1tcm_size;
> > phys_addr_t l1tcm_phys;
> > struct list_head mtk_scp_list;
> > +
> > + /* Prevent concurrent operations of L2TCM power control. */
> > + struct mutex l2tcm_lock;
> > + u32 l2tcm_refcnt;
> > };
> >
> > /**
> > @@ -449,7 +453,7 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
> >
> > writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
> >
> > - /* enable SRAM clock */
> > + /* enable SRAM power */
> > scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > @@ -462,19 +466,38 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
> > return 0;
> > }
> >
> > -static int mt8195_scp_before_load(struct mtk_scp *scp)
> > +static int mt8195_scp_l2tcm_on(struct mtk_scp *scp)
> > {
> > - /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> > - writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> > + struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
> > +
> > + mutex_lock(&scp_cluster->l2tcm_lock);
> > +
> > + if (scp_cluster->l2tcm_refcnt == 0) {
> > + /* clear SPM interrupt, SCP2SPM_IPC_CLR */
> > + writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
> > +
> > + /* Power on L2TCM */
> > + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > + scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > + scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> > + MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> > + }
> > +
> > + scp_cluster->l2tcm_refcnt += 1;
> >
> > + mutex_unlock(&scp_cluster->l2tcm_lock);
> > +
> > + return 0;
> > +}
> > +
> > +static int mt8195_scp_before_load(struct mtk_scp *scp)
> > +{
> > writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
> >
> > + mt8195_scp_l2tcm_on(scp);
> > +
> > /* enable SRAM clock */
> > - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > - scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > - scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> > - MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> > scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> >
> > /* enable MPU for all memory regions */
> > @@ -487,6 +510,8 @@ static int mt8195_scp_c1_before_load(struct mtk_scp *scp)
> > {
> > scp->data->scp_reset_assert(scp);
> >
> > + mt8195_scp_l2tcm_on(scp);
> > +
> > scp_sram_power_on(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);
> >
> > /* enable MPU for all memory regions */
> > @@ -653,14 +678,30 @@ static void mt8192_scp_stop(struct mtk_scp *scp)
> > writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
> > }
> >
> > +static void mt8195_scp_l2tcm_off(struct mtk_scp *scp)
> > +{
> > + struct mtk_scp_of_cluster *scp_cluster = platform_get_drvdata(scp->cluster_pdev);
> > +
> > + mutex_lock(&scp_cluster->l2tcm_lock);
> > +
>
> What happens if ->l2tcm_refcnt is 0 and this function is called?

Thanks, I'll check this condition in the next version.


Best regards,
TingHan.

>
>
> > + scp_cluster->l2tcm_refcnt -= 1;
> > +
> > + if (scp_cluster->l2tcm_refcnt == 0) {
> > + /* Power off L2TCM */
> > + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
> > + scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> > + }
> > +
> > + mutex_unlock(&scp_cluster->l2tcm_lock);
> > +}
> > +
> > static void mt8195_scp_stop(struct mtk_scp *scp)
> > {
> > - /* Disable SRAM clock */
> > - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
> > - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
> > - scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
> > - scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
> > - MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS);
> > + mt8195_scp_l2tcm_off(scp);
> > +
> > scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
> >
> > /* Disable SCP watchdog */
> > @@ -669,6 +710,8 @@ static void mt8195_scp_stop(struct mtk_scp *scp)
> >
> > static void mt8195_scp_c1_stop(struct mtk_scp *scp)
> > {
> > + mt8195_scp_l2tcm_off(scp);
> > +
> > /* Power off CPU SRAM */
> > scp_sram_power_off(scp->reg_base + MT8195_CPU1_SRAM_PD, 0);
> >
> > @@ -976,6 +1019,8 @@ static int scp_add_single_core(struct platform_device *pdev)
> > if (IS_ERR(scp))
> > return PTR_ERR(scp);
> >
> > + scp->cluster_pdev = pdev;
> > +
> > ret = rproc_add(scp->rproc);
> > if (ret) {
> > dev_err(dev, "Failed to add rproc\n");
> > @@ -1028,6 +1073,8 @@ static int scp_add_multi_core(struct platform_device *pdev)
> > goto init_fail;
> > }
> >
> > + scp->cluster_pdev = pdev;
> > +
> > ret = rproc_add(scp->rproc);
> > if (ret) {
> > dev_err(dev, "Failed to add rproc of core %d\n", core_id);
> > @@ -1114,6 +1161,7 @@ static int scp_probe(struct platform_device *pdev)
> > }
> >
> > INIT_LIST_HEAD(&scp_cluster->mtk_scp_list);
> > + mutex_init(&scp_cluster->l2tcm_lock);
> > platform_set_drvdata(pdev, scp_cluster);
> >
> > ret = devm_of_platform_populate(dev);
> > @@ -1137,6 +1185,8 @@ static void scp_remove(struct platform_device *pdev)
> > rproc_del(scp->rproc);
> > scp_free(scp);
> > }
> > +
> > + mutex_destroy(&scp_cluster->l2tcm_lock);
> > }
> >
> > static const struct mtk_scp_of_data mt8183_of_data = {
> > --
> > 2.18.0

--
Best regards,
TingHan