| Message ID | 20200509130825.28248-1-shawn.guo@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | iommu/qcom: add optional clock for TLB invalidate | expand |
Hi Stanimir, On Sat, May 09, 2020 at 04:21:20PM +0300, Stanimir Varbanov wrote: ... > > @@ -839,6 +849,12 @@ static int qcom_iommu_device_probe(struct platform_device *pdev) > > return PTR_ERR(qcom_iommu->bus_clk); > > } > > > > + qcom_iommu->tlb_clk = devm_clk_get(dev, "tlb"); > > IMO, devm_clk_get_optional() would be better. Yes, indeed. The function will make it clear that the clock is an optional one. I will make the change in v2. Thanks for the comment! Shawn
Hi Bjorn, On Mon, May 11, 2020 at 10:52:42PM -0700, Bjorn Andersson wrote: > On Sat 09 May 06:08 PDT 2020, Shawn Guo wrote: > > > On some SoCs like MSM8939 with A405 adreno, there is a gfx_tbu clock > > needs to be on while doing TLB invalidate. Otherwise, TLBSYNC status > > will not be correctly reflected, causing the system to go into a bad > > state. Add it as an optional clock, so that platforms that have this > > clock can pass it over DT. > > > > Signed-off-by: Shawn Guo <shawn.guo@linaro.org> > > --- > > drivers/iommu/qcom_iommu.c | 16 ++++++++++++++++ > > 1 file changed, 16 insertions(+) > > > > diff --git a/drivers/iommu/qcom_iommu.c b/drivers/iommu/qcom_iommu.c > > index 0e2a96467767..2f6c6da7d540 100644 > > --- a/drivers/iommu/qcom_iommu.c > > +++ b/drivers/iommu/qcom_iommu.c > > @@ -45,6 +45,7 @@ struct qcom_iommu_dev { > > struct device *dev; > > struct clk *iface_clk; > > struct clk *bus_clk; > > + struct clk *tlb_clk; > > void __iomem *local_base; > > u32 sec_id; > > u8 num_ctxs; > > @@ -643,11 +644,20 @@ static int qcom_iommu_enable_clocks(struct qcom_iommu_dev *qcom_iommu) > > return ret; > > } > > > > + ret = clk_prepare_enable(qcom_iommu->tlb_clk); > > + if (ret) { > > + dev_err(qcom_iommu->dev, "Couldn't enable tlb_clk\n"); > > + clk_disable_unprepare(qcom_iommu->bus_clk); > > + clk_disable_unprepare(qcom_iommu->iface_clk); > > + return ret; > > + } > > Seems this is an excellent opportunity to replace > qcom_iommu_enable_clocks() to clk_bulk_prepare_enable() and disable, > respectively. So we have two required and one optional clocks. I guess we don't want to use clk_bulk_get_optional() to get all of them as optional. So we will end up with getting clock with individual call and enabling/disabling with bulk version. I'm personally not fond of this mixed style. But if you really like this, I can change. > > > + > > return 0; > > } > > > > static void qcom_iommu_disable_clocks(struct qcom_iommu_dev *qcom_iommu) > > { > > + clk_disable_unprepare(qcom_iommu->tlb_clk); > > clk_disable_unprepare(qcom_iommu->bus_clk); > > clk_disable_unprepare(qcom_iommu->iface_clk); > > } > > @@ -839,6 +849,12 @@ static int qcom_iommu_device_probe(struct platform_device *pdev) > > return PTR_ERR(qcom_iommu->bus_clk); > > } > > > > + qcom_iommu->tlb_clk = devm_clk_get(dev, "tlb"); > > Wouldn't "tbu" be a better name for this clock? Given that seems the > actually be the hardware block you're clocking. I was trying to emphasize the function of this clock. But I agree that 'tbu' is a better name now. I will change it in v2. Thanks for the comments. Shawn
diff --git a/drivers/iommu/qcom_iommu.c b/drivers/iommu/qcom_iommu.c index 0e2a96467767..2f6c6da7d540 100644 --- a/drivers/iommu/qcom_iommu.c +++ b/drivers/iommu/qcom_iommu.c @@ -45,6 +45,7 @@ struct qcom_iommu_dev { struct device *dev; struct clk *iface_clk; struct clk *bus_clk; + struct clk *tlb_clk; void __iomem *local_base; u32 sec_id; u8 num_ctxs; @@ -643,11 +644,20 @@ static int qcom_iommu_enable_clocks(struct qcom_iommu_dev *qcom_iommu) return ret; } + ret = clk_prepare_enable(qcom_iommu->tlb_clk); + if (ret) { + dev_err(qcom_iommu->dev, "Couldn't enable tlb_clk\n"); + clk_disable_unprepare(qcom_iommu->bus_clk); + clk_disable_unprepare(qcom_iommu->iface_clk); + return ret; + } + return 0; } static void qcom_iommu_disable_clocks(struct qcom_iommu_dev *qcom_iommu) { + clk_disable_unprepare(qcom_iommu->tlb_clk); clk_disable_unprepare(qcom_iommu->bus_clk); clk_disable_unprepare(qcom_iommu->iface_clk); } @@ -839,6 +849,12 @@ static int qcom_iommu_device_probe(struct platform_device *pdev) return PTR_ERR(qcom_iommu->bus_clk); } + qcom_iommu->tlb_clk = devm_clk_get(dev, "tlb"); + if (IS_ERR(qcom_iommu->tlb_clk)) { + dev_dbg(dev, "failed to get tlb clock\n"); + qcom_iommu->tlb_clk = NULL; + } + if (of_property_read_u32(dev->of_node, "qcom,iommu-secure-id", &qcom_iommu->sec_id)) { dev_err(dev, "missing qcom,iommu-secure-id property\n");
On some SoCs like MSM8939 with A405 adreno, there is a gfx_tbu clock needs to be on while doing TLB invalidate. Otherwise, TLBSYNC status will not be correctly reflected, causing the system to go into a bad state. Add it as an optional clock, so that platforms that have this clock can pass it over DT. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> --- drivers/iommu/qcom_iommu.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)