iommu/exynos: Turn on useful configuration options

This turns on FLPD_CACHE, ACGEN and SYSSEL.

FLPD_CACHE is a cache of 1st level page table entries that contains
the address of a 2nd level page table to reduce latency of page table
walking.

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.

This patch also adds simplifies the sysmmu version checking by
introducing some macros.

Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
Signed-off-by: Shaik Ameer Basha <shaik.ameer@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 34 insertions, 4 deletions

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index b937490fdd5d..26fb4d777ae2 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -93,6 +93,13 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
 #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
 #define REG_MMU_CFG             0x004
 #define REG_MMU_STATUS          0x008
@@ -109,6 +116,12 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
 
 #define REG_MMU_VERSION         0x034
 
+#define MMU_MAJ_VER(val)        ((val) >> 7)
+#define MMU_MIN_VER(val)        ((val) & 0x7F)
+#define MMU_RAW_VER(reg)        (((reg) >> 21) & ((1 << 11) - 1)) /* 11 bits */
+
+#define MAKE_MMU_VER(maj, min)  ((((maj) & 0xF) << 7) | ((min) & 0x7F))
+
 #define REG_PB0_SADDR           0x04C
 #define REG_PB0_EADDR           0x050
 #define REG_PB1_SADDR           0x054
@@ -219,6 +232,11 @@ static void sysmmu_unblock(void __iomem *sfrbase)
         __raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
 }
 
+static unsigned int __raw_sysmmu_version(struct sysmmu_drvdata *data)
+{
+        return MMU_RAW_VER(__raw_readl(data->sfrbase + REG_MMU_VERSION));
+}
+
 static bool sysmmu_block(void __iomem *sfrbase)
 {
         int i = 120;
@@ -374,7 +392,21 @@ static bool __sysmmu_disable(struct sysmmu_drvdata *data)
 
 static void __sysmmu_init_config(struct sysmmu_drvdata *data)
 {
-        unsigned int cfg = 0;
+        unsigned int cfg = CFG_LRU | CFG_QOS(15);
+        unsigned int ver;
+
+        ver = __raw_sysmmu_version(data);
+        if (MMU_MAJ_VER(ver) == 3) {
+                if (MMU_MIN_VER(ver) >= 2) {
+                        cfg |= CFG_FLPDCACHE;
+                        if (MMU_MIN_VER(ver) == 3) {
+                                cfg |= CFG_ACGEN;
+                                cfg &= ~CFG_LRU;
+                        } else {
+                                cfg |= CFG_SYSSEL;
+                        }
+                }
+        }
 
         __raw_writel(cfg, data->sfrbase + REG_MMU_CFG);
 }
@@ -494,13 +526,11 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, sysmmu_iova_t iova,
 
         spin_lock_irqsave(&data->lock, flags);
         if (is_sysmmu_active(data)) {
-                unsigned int maj;
                 unsigned int num_inv = 1;
 
                 if (!IS_ERR(data->clk_master))
                         clk_enable(data->clk_master);
 
-                maj = __raw_readl(data->sfrbase + REG_MMU_VERSION);
                 /*
                  * L2TLB invalidation required
                  * 4KB page: 1 invalidation
@@ -511,7 +541,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, sysmmu_iova_t iova,
                  * 1MB page can be cached in one of all sets.
                  * 64KB page can be one of 16 consecutive sets.
                  */
-                if ((maj >> 28) == 2) /* major version number */
+                if (MMU_MAJ_VER(__raw_sysmmu_version(data)) == 2)
                         num_inv = min_t(unsigned int, size / PAGE_SIZE, 64);
 
                 if (sysmmu_block(data->sfrbase)) {