Messages in this thread | | | Subject | Re: [PATCH v4 12/24] iommu/mediatek: Move hw_init into attach_device | From | Robin Murphy <> | Date | Thu, 26 Nov 2020 16:43:54 +0000 |
| |
On 2020-11-11 12:38, Yong Wu wrote: > In attach device, it will update the pagetable base address register. > Move the hw_init function also here. Then it only need call > pm_runtime_get/put one time here if m4u has power domain.
Doesn't that mean you'll end up writing most of the registers twice every time? (first from mtk_iommu_resume(), then again from mtk_iommu_hw_init())
It might be neater to have mtk_iommu_hw_init() simply populate the mtk_iommu_suspend_reg data with the initial values at probe time and manually call mtk_iommu_resume() if the hardware is already powered up at that point. Or maybe just don't bother saving those registers on suspend and put the initialisation directly in the resume path.
Robin.
> Signed-off-by: Yong Wu <yong.wu@mediatek.com> > --- > drivers/iommu/mtk_iommu.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index 55f9b329e637..cfdf5ce696fd 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -125,6 +125,8 @@ struct mtk_iommu_domain { > > static const struct iommu_ops mtk_iommu_ops; > > +static int mtk_iommu_hw_init(const struct mtk_iommu_data *data); > + > /* > * In M4U 4GB mode, the physical address is remapped as below: > * > @@ -380,12 +382,16 @@ 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_hw_init(data); > + if (ret) > + return ret; > data->m4u_dom = dom; > writel(dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK, > data->base + REG_MMU_PT_BASE_ADDR); > @@ -729,10 +735,6 @@ static int mtk_iommu_probe(struct platform_device *pdev) > > platform_set_drvdata(pdev, data); > > - ret = mtk_iommu_hw_init(data); > - if (ret) > - return ret; > - > ret = iommu_device_sysfs_add(&data->iommu, dev, NULL, > "mtk-iommu.%pa", &ioaddr); > if (ret) >
| |