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@xxxxxxxxxxxx>
---
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)
