This turns on ACGEN and SYSSEL. ACGEN is architectural clock gating that gates clocks by System MMU itself if it is not active. Note that ACGEN is different from clock gating by the CPU. ACGEN just gates clocks to the internal logic of System MMU while clock gating by the CPU gates clocks to the System MMU. SYSSEL selects System MMU version in some Exynos SoCs. Some Exynos SoCs have an option to select System MMU versions exclusively because the SoCs adopts new System MMU version experimentally. This also always selects LRU as TLB replacement policy. Selecting TLB replacement policy is deprecated from System MMU 3.2. TLB in System MMU 3.3 has single TLB replacement policy, LRU. The bit of MMU_CFG selecting TLB replacement policy is remained as reserved. QoS value of page table walking is set to 15 (highst value). System MMU 3.3 can inherit QoS value of page table walking from its master H/W's transaction. This new feature is enabled by default and QoS value written to MMU_CFG is ignored. Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx> --- drivers/iommu/exynos-iommu.c | 20 +++++++++++++++++--- 1 files changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index d9c5416..03031dc 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -82,6 +82,11 @@ #define CTRL_BLOCK 0x7 #define CTRL_DISABLE 0x0 +#define CFG_LRU 0x1 +#define CFG_QOS(n) ((n & 0xF) << 7) +#define CFG_MASK 0x0150FFFF /* Selecting bit 0-15, 20, 22 and 24 */ +#define CFG_ACGEN (1 << 24) /* System MMU 3.3 only */ +#define CFG_SYSSEL (1 << 22) /* System MMU 3.2 only */ #define CFG_FLPDCACHE (1 << 20) /* System MMU 3.2+ only */ #define REG_MMU_CTRL 0x000 @@ -372,12 +377,21 @@ static bool __sysmmu_disable(struct sysmmu_drvdata *data) static void __sysmmu_init_config(struct sysmmu_drvdata *data) { - unsigned long cfg = 0; + unsigned long cfg = CFG_LRU | CFG_QOS(15); int maj, min = 0; maj = __sysmmu_version(data, &min); - if ((maj == 3) && (min > 1)) - cfg |= CFG_FLPDCACHE; + if (maj == 3) { + if (min >= 2) { + cfg |= CFG_FLPDCACHE; + if (min == 3) { + cfg |= CFG_ACGEN; + cfg &= ~CFG_LRU; + } else { + cfg |= CFG_SYSSEL; + } + } + } __raw_writel(cfg, data->sfrbase + REG_MMU_CFG); } -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html