Re: [PATCH v4 12/24] iommu/mediatek: Move hw_init into attach_device
From: Robin Murphy <robin.murphy@arm.com>
Date: 2020-11-26 16:44:01
Also in:
linux-devicetree, linux-iommu, linux-mediatek, lkml
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.
quoted hunk ↗ jump to hunk
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)
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