[PATCH 2/5] iommu/mediatek: Add mt8173 IOMMU driver

On Mon, Mar 09 2015 at 05:16:26 AM, Yong Wu [off-list ref] wrote:

Dear Mitchel,
     Thanks very much for your review.

On Fri, 2015-03-06 at 09:15 -0800, Mitchel Humpherys wrote:

quoted

On Fri, Mar 06 2015 at 02:48:17 AM, [off-list ref] wrote:

quoted

From: Yong Wu <yong.wu@mediatek.com>

This patch adds support for mediatek m4u (MultiMedia Memory Management Unit).
Currently this only supports m4u gen 2 with 2 levels of page table on mt8173.

[...]

quoted

+static int mtk_iommu_invalidate_tlb(const struct mtk_iommu_info *piommu,
+				    int isinvall, unsigned int iova_start,
+				    unsigned int iova_end)
+{
+	void __iomem *m4u_base = piommu->m4u_base;
+	u32 val;
+	u64 start, end;
+
+	start = sched_clock();
+
+	if (!isinvall) {
+		iova_start = round_down(iova_start, SZ_4K);
+		iova_end = round_up(iova_end, SZ_4K);
+	}
+
+	val = F_MMU_INV_EN_L2 | F_MMU_INV_EN_L1;
+
+	writel(val, m4u_base + REG_INVLID_SEL);
+
+	if (isinvall) {
+		writel(F_MMU_INV_ALL, m4u_base + REG_MMU_INVLD);
+	} else {
+		writel(iova_start, m4u_base + REG_MMU_INVLD_SA);
+		writel(iova_end, m4u_base + REG_MMU_INVLD_EA);
+		writel(F_MMU_INV_RANGE, m4u_base + REG_MMU_INVLD);
+
+		while (!readl(m4u_base + REG_MMU_CPE_DONE)) {
+			end = sched_clock();
+			if (end - start >= 100000000ULL) {
+				dev_warn(piommu->dev, "invalid don't done\n");
+				writel(F_MMU_INV_ALL, m4u_base + REG_MMU_INVLD);
+			}
+		};

Superfluous `;'.  Also, maybe you should be using readl_poll_timeout?

   Thanks.
   For the "readl_poll_timeout", My base is 3.19-rc7 and robin's patch.
it don't have this interface.  I will try to add it in the next version.

Yeah it was merged in v4.0-rc1.

-Mitch

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