Prefetch buffer must be handled accurately, exact range of a buffer,
frame by frame manually. Otherwise, it may causes page fault or
deadlock in System MMU.
Thus this patch removes prefetch buffer setting when System MMU is
initialized(enabled).
Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 32 +++++++++++++++++++++++++++-----
1 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index cfc02ed..87f6bb7 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -80,6 +80,8 @@
#define CTRL_BLOCK 0x7
#define CTRL_DISABLE 0x0
+#define CFG_FLPDCACHE (1 << 20) /* System MMU 3.2+ only */
+
#define REG_MMU_CTRL 0x000
#define REG_MMU_CFG 0x004
#define REG_MMU_STATUS 0x008
@@ -96,6 +98,9 @@
#define REG_MMU_VERSION 0x034
+#define MMU_MAJ_VER(reg) (reg >> 28)
+#define MMU_MIN_VER(reg) ((reg >> 21) & 0x7F)
+
#define REG_PB0_SADDR 0x04C
#define REG_PB0_EADDR 0x050
#define REG_PB1_SADDR 0x054
@@ -200,6 +205,22 @@ static bool is_sysmmu_active(struct sysmmu_drvdata *data)
return data->activations > 0;
}
+static unsigned int __sysmmu_version(struct sysmmu_drvdata *data,
+ int idx, unsigned int *minor)
+{
+ unsigned long major;
+
+ major = readl(data->sfrbases[idx] + REG_MMU_VERSION);
+
+ if (minor)
+ *minor = MMU_MIN_VER(major);
+
+ if (MMU_MAJ_VER(major) > 3)
+ return 1;
+
+ return MMU_MAJ_VER(major);
+}
+
static void sysmmu_unblock(void __iomem *sfrbase)
{
__raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
@@ -460,14 +481,15 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
data->pgtable = pgtable;
for (i = 0; i < data->nsfrs; i++) {
+ unsigned int min;
+
__sysmmu_set_ptbase(data->sfrbases[i], pgtable);
- if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
- /* System MMU version is 3.x */
- __raw_writel((1 << 12) | (2 << 28),
+ if ((__sysmmu_version(data, i, &min) == 3) && (min > 1)) {
+ unsigned long cfg;
+ cfg = __raw_readl(data->sfrbases[i] + REG_MMU_CFG);
+ __raw_writel(cfg | CFG_FLPDCACHE,
data->sfrbases[i] + REG_MMU_CFG);
- __sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 0);
- __sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 1);
}
__raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
--
1.7.2.5
--
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