From 2f26ec16f67be54bee080a9f9cacf10222fea64a Mon Sep 17 00:00:00 2001 From: Cho KyongHo Date: Fri, 26 Jul 2013 20:28:49 +0900 Subject: [PATCH] iommu/exynos: remove prefetch buffer setting when enabling System MMU 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 --- drivers/iommu/exynos-iommu.c | 32 +++++++++++++++++++++++++++----- 1 file 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); -- 2.7.4