On Sat, 2020-07-11 at 14:48 +0800, Yong Wu wrote:
> In the previous SoC, the M4U HW is in the EMI power domain which is
> always on. the latest M4U is in the display power domain which may be
> turned on/off, thus we have to add pm_runtime interface for it.
>
> we should enable its power before M4U hw initial. and disable it after HW
> initialize.
>
> When the engine work, the engine always enable the power and clocks for
> smi-larb/smi-common, then the M4U's power will always be powered on
> automatically via the device link with smi-common.
>
> Note: we don't enable the M4U power in iommu_map/unmap for tlb flush.
> If its power already is on, of course it is ok. if the power is off,
> the main tlb will be reset while M4U power on, thus the tlb flush while
> m4u power off is unnecessary, just skip it.
>
> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> ---
> drivers/iommu/mtk_iommu.c | 54 ++++++++++++++++++++++++++++++++++-----
> 1 file changed, 47 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 931fdd19c8f3..03a6d66f4bef 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -20,6 +20,7 @@
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/slab.h>
> #include <linux/spinlock.h>
> #include <asm/barrier.h>
> @@ -172,6 +173,19 @@ static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
> return container_of(dom, struct mtk_iommu_domain, domain);
> }
>
> +static int mtk_iommu_rpm_get(struct device *dev)
> +{
> + if (pm_runtime_enabled(dev))
> + return pm_runtime_get_sync(dev);
> + return 0;
> +}
> +
> +static void mtk_iommu_rpm_put(struct device *dev)
> +{
> + if (pm_runtime_enabled(dev))
> + pm_runtime_put_autosuspend(dev);
> +}
> +
> static void mtk_iommu_tlb_flush_all(void *cookie)
> {
> struct mtk_iommu_data *data = cookie;
> @@ -193,6 +207,11 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
> u32 tmp;
>
> for_each_m4u(data) {
> + /* skip tlb flush when pm is not active */
> + if (pm_runtime_enabled(data->dev) &&
> + !pm_runtime_active(data->dev))
> + continue;
> +
> spin_lock_irqsave(&data->tlb_lock, flags);
> writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
> data->base + data->plat_data->inv_sel_reg);
> @@ -377,15 +396,20 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
> {
> struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
> struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> + int ret;
>
> if (!data)
> return -ENODEV;
>
> /* Update the pgtable base address register of the M4U HW */
> if (!data->m4u_dom) {
> + ret = mtk_iommu_rpm_get(dev);
> + if (ret < 0)
> + return ret;
> data->m4u_dom = dom;
> writel(dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK,
> data->base + REG_MMU_PT_BASE_ADDR);
> + mtk_iommu_rpm_put(dev);
> }
>
> mtk_iommu_config(data, dev, true);
> @@ -543,10 +567,14 @@ static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
> u32 regval;
> int ret;
>
> - ret = clk_prepare_enable(data->bclk);
> - if (ret) {
> - dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
> - return ret;
> + /* bclk will be enabled in pm callback in power-domain case. */
> + if (!pm_runtime_enabled(data->dev)) {
> + ret = clk_prepare_enable(data->bclk);
> + if (ret) {
> + dev_err(data->dev, "Failed to enable iommu bclk(%d)\n",
> + ret);
> + return ret;
> + }
> }
>
> if (data->plat_data->m4u_plat == M4U_MT8173) {
> @@ -728,7 +756,15 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, data);
>
> + if (dev->pm_domain)
> + pm_runtime_enable(dev);
hi yong,
If you put "pm_runtime_enable" here, it maybe not device_link with
smi_common for previous patch:
if(i || !pm_runtime_enabled(dev))
continue;
Whether put it up front?
best regards,
chao
> +
> + ret = mtk_iommu_rpm_get(dev);
> + if (ret < 0)
> + return ret;
> +
> ret = mtk_iommu_hw_init(data);
> + mtk_iommu_rpm_put(dev);
> if (ret)
> return ret;
>
> @@ -801,6 +837,10 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
> dev_err(data->dev, "Failed to enable clk(%d) in resume\n", ret);
> return ret;
> }
> +
> + /* Avoid first resume to affect the default value of registers below. */
> + if (!m4u_dom)
> + return 0;
> writel_relaxed(reg->wr_len_ctrl, base + REG_MMU_WR_LEN_CTRL);
> writel_relaxed(reg->misc_ctrl, base + REG_MMU_MISC_CTRL);
> writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM_DIS);
> @@ -809,13 +849,13 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
> writel_relaxed(reg->int_main_control, base + REG_MMU_INT_MAIN_CONTROL);
> writel_relaxed(reg->ivrp_paddr, base + REG_MMU_IVRP_PADDR);
> writel_relaxed(reg->vld_pa_rng, base + REG_MMU_VLD_PA_RNG);
> - if (m4u_dom)
> - writel(m4u_dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK,
> - base + REG_MMU_PT_BASE_ADDR);
> + writel(m4u_dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK,
> + base + REG_MMU_PT_BASE_ADDR);
> return 0;
> }
>
> static const struct dev_pm_ops mtk_iommu_pm_ops = {
> + SET_RUNTIME_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume, NULL)
> SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
> };
>
