| Message ID | 20230505113856.463650-15-s.hauer@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add perf support to the rockchip-dfi driver | expand |
On Fri, 5 May 2023 13:38:49 +0200 Sascha Hauer <s.hauer@pengutronix.de> wrote: > When adding perf support later the DFI must be enabled when > either of devfreq-event or perf is active. Prepare for that > by adding a usage counter for the DFI. Also move enabling > and disabling of the clock away from the devfreq-event specific > functions to which the perf specific part won't have access. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> The clock code is IIRC refcounted anyway and I think has appropriate locks, so you code just enable / disable that in both paths. Probably not that helpful though given you still need to refcount to protect the register writes. So this looks fine to me. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/devfreq/event/rockchip-dfi.c | 57 +++++++++++++++++++--------- > 1 file changed, 40 insertions(+), 17 deletions(-) > > diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c > index c0b7b1e9805e9..eae010644935a 100644 > --- a/drivers/devfreq/event/rockchip-dfi.c > +++ b/drivers/devfreq/event/rockchip-dfi.c > @@ -69,13 +69,28 @@ struct rockchip_dfi { > void __iomem *regs; > struct regmap *regmap_pmu; > struct clk *clk; > + int usecount; > + struct mutex mutex; > u32 ddr_type; > unsigned int channel_mask; > }; > > -static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi) > +static int rockchip_dfi_enable(struct rockchip_dfi *dfi) > { > void __iomem *dfi_regs = dfi->regs; > + int ret = 0; > + > + mutex_lock(&dfi->mutex); > + > + dfi->usecount++; > + if (dfi->usecount > 1) > + goto out; > + > + ret = clk_prepare_enable(dfi->clk); > + if (ret) { > + dev_err(&dfi->edev->dev, "failed to enable dfi clk: %d\n", ret); > + goto out; > + } > > /* clear DDRMON_CTRL setting */ > writel_relaxed(HIWORD_UPDATE(0, 0xffff), dfi_regs + DDRMON_CTRL); > @@ -99,14 +114,30 @@ static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi) > /* enable count, use software mode */ > writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN), > dfi_regs + DDRMON_CTRL); > +out: > + mutex_unlock(&dfi->mutex); > + > + return ret; > } > > -static void rockchip_dfi_stop_hardware_counter(struct rockchip_dfi *dfi) > +static void rockchip_dfi_disable(struct rockchip_dfi *dfi) > { > void __iomem *dfi_regs = dfi->regs; > > + mutex_lock(&dfi->mutex); > + > + dfi->usecount--; > + > + WARN_ON_ONCE(dfi->usecount < 0); > + > + if (dfi->usecount > 0) > + goto out; > + > writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN), > dfi_regs + DDRMON_CTRL); > + clk_disable_unprepare(dfi->clk); > +out: > + mutex_unlock(&dfi->mutex); > } > > static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_count *count) > @@ -124,29 +155,20 @@ static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_coun > } > } > > -static int rockchip_dfi_disable(struct devfreq_event_dev *edev) > +static int rockchip_dfi_event_disable(struct devfreq_event_dev *edev) > { > struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev); > > - rockchip_dfi_stop_hardware_counter(dfi); > - clk_disable_unprepare(dfi->clk); > + rockchip_dfi_disable(dfi); Similar to below. Up to you on whether you prefer shorter code vs having the type of the parameter explicit in here. > > return 0; > } > > -static int rockchip_dfi_enable(struct devfreq_event_dev *edev) > +static int rockchip_dfi_event_enable(struct devfreq_event_dev *edev) > { > struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev); > - int ret; > - > - ret = clk_prepare_enable(dfi->clk); > - if (ret) { > - dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret); > - return ret; > - } > > - rockchip_dfi_start_hardware_counter(dfi); > - return 0; > + return rockchip_dfi_enable(dfi); No real point in local variable any more, so maybe return rockchip_dfi_enable(devfreq_event_get_drvdata(edev)); > } > > static int rockchip_dfi_set_event(struct devfreq_event_dev *edev) > @@ -190,8 +212,8 @@ static int rockchip_dfi_get_event(struct devfreq_event_dev *edev, > } > > static const struct devfreq_event_ops rockchip_dfi_ops = { > - .disable = rockchip_dfi_disable, > - .enable = rockchip_dfi_enable, > + .disable = rockchip_dfi_event_disable, > + .enable = rockchip_dfi_event_enable, > .get_event = rockchip_dfi_get_event, > .set_event = rockchip_dfi_set_event, > }; > @@ -285,6 +307,7 @@ static int rockchip_dfi_probe(struct platform_device *pdev) > return PTR_ERR(dfi->regmap_pmu); > > dfi->dev = dev; > + mutex_init(&dfi->mutex); > > desc = &dfi->desc; > desc->ops = &rockchip_dfi_ops;
diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c index c0b7b1e9805e9..eae010644935a 100644 --- a/drivers/devfreq/event/rockchip-dfi.c +++ b/drivers/devfreq/event/rockchip-dfi.c @@ -69,13 +69,28 @@ struct rockchip_dfi { void __iomem *regs; struct regmap *regmap_pmu; struct clk *clk; + int usecount; + struct mutex mutex; u32 ddr_type; unsigned int channel_mask; }; -static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi) +static int rockchip_dfi_enable(struct rockchip_dfi *dfi) { void __iomem *dfi_regs = dfi->regs; + int ret = 0; + + mutex_lock(&dfi->mutex); + + dfi->usecount++; + if (dfi->usecount > 1) + goto out; + + ret = clk_prepare_enable(dfi->clk); + if (ret) { + dev_err(&dfi->edev->dev, "failed to enable dfi clk: %d\n", ret); + goto out; + } /* clear DDRMON_CTRL setting */ writel_relaxed(HIWORD_UPDATE(0, 0xffff), dfi_regs + DDRMON_CTRL); @@ -99,14 +114,30 @@ static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi) /* enable count, use software mode */ writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN), dfi_regs + DDRMON_CTRL); +out: + mutex_unlock(&dfi->mutex); + + return ret; } -static void rockchip_dfi_stop_hardware_counter(struct rockchip_dfi *dfi) +static void rockchip_dfi_disable(struct rockchip_dfi *dfi) { void __iomem *dfi_regs = dfi->regs; + mutex_lock(&dfi->mutex); + + dfi->usecount--; + + WARN_ON_ONCE(dfi->usecount < 0); + + if (dfi->usecount > 0) + goto out; + writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN), dfi_regs + DDRMON_CTRL); + clk_disable_unprepare(dfi->clk); +out: + mutex_unlock(&dfi->mutex); } static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_count *count) @@ -124,29 +155,20 @@ static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_coun } } -static int rockchip_dfi_disable(struct devfreq_event_dev *edev) +static int rockchip_dfi_event_disable(struct devfreq_event_dev *edev) { struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev); - rockchip_dfi_stop_hardware_counter(dfi); - clk_disable_unprepare(dfi->clk); + rockchip_dfi_disable(dfi); return 0; } -static int rockchip_dfi_enable(struct devfreq_event_dev *edev) +static int rockchip_dfi_event_enable(struct devfreq_event_dev *edev) { struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev); - int ret; - - ret = clk_prepare_enable(dfi->clk); - if (ret) { - dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret); - return ret; - } - rockchip_dfi_start_hardware_counter(dfi); - return 0; + return rockchip_dfi_enable(dfi); } static int rockchip_dfi_set_event(struct devfreq_event_dev *edev) @@ -190,8 +212,8 @@ static int rockchip_dfi_get_event(struct devfreq_event_dev *edev, } static const struct devfreq_event_ops rockchip_dfi_ops = { - .disable = rockchip_dfi_disable, - .enable = rockchip_dfi_enable, + .disable = rockchip_dfi_event_disable, + .enable = rockchip_dfi_event_enable, .get_event = rockchip_dfi_get_event, .set_event = rockchip_dfi_set_event, }; @@ -285,6 +307,7 @@ static int rockchip_dfi_probe(struct platform_device *pdev) return PTR_ERR(dfi->regmap_pmu); dfi->dev = dev; + mutex_init(&dfi->mutex); desc = &dfi->desc; desc->ops = &rockchip_dfi_ops;
When adding perf support later the DFI must be enabled when either of devfreq-event or perf is active. Prepare for that by adding a usage counter for the DFI. Also move enabling and disabling of the clock away from the devfreq-event specific functions to which the perf specific part won't have access. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> --- drivers/devfreq/event/rockchip-dfi.c | 57 +++++++++++++++++++--------- 1 file changed, 40 insertions(+), 17 deletions(-)