iommu/mediatek: Support master use iova over 32bit

After extending v7s, our pagetable already support iova reach
16GB(34bit). the master got the iova via dma_alloc_attrs may reach
34bits, but its HW register still is 32bit. then how to set the
bit32/bit33 iova? this depend on a SMI larb setting(bank_sel).

we separate whole 16GB iova to four banks:
bank: 0: 0~4G; 1: 4~8G; 2: 8-12G; 3: 12-16G;
The bank number is (iova >> 32).

We will preassign which bank the larbs belong to. currently we don't
have a interface for master to adjust its bank number.

Each a bank is a iova_region which is a independent iommu-domain.
the iova range for each iommu-domain can't cross 4G.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org> #for memory part
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-31-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index 89f92fa2..fae61c5 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -44,6 +44,10 @@
 /* mt2712 */
 #define SMI_LARB_NONSEC_CON(id)	(0x380 + ((id) * 4))
 #define F_MMU_EN		BIT(0)
+#define BANK_SEL(id)		({			\
+	u32 _id = (id) & 0x3;				\
+	(_id << 8 | _id << 10 | _id << 12 | _id << 14);	\
+})
 
 /* SMI COMMON */
 #define SMI_BUS_SEL			0x220
@@ -88,6 +92,7 @@ struct mtk_smi_larb { /* larb: local arbiter */
 	const struct mtk_smi_larb_gen	*larb_gen;
 	int				larbid;
 	u32				*mmu;
+	unsigned char			*bank;
 };
 
 static int mtk_smi_clk_enable(const struct mtk_smi *smi)
@@ -154,6 +159,7 @@ mtk_smi_larb_bind(struct device *dev, struct device *master, void *data)
 		if (dev == larb_mmu[i].dev) {
 			larb->larbid = i;
 			larb->mmu = &larb_mmu[i].mmu;
+			larb->bank = larb_mmu[i].bank;
 			return 0;
 		}
 	}
@@ -172,6 +178,7 @@ static void mtk_smi_larb_config_port_gen2_general(struct device *dev)
 	for_each_set_bit(i, (unsigned long *)larb->mmu, 32) {
 		reg = readl_relaxed(larb->base + SMI_LARB_NONSEC_CON(i));
 		reg |= F_MMU_EN;
+		reg |= BANK_SEL(larb->bank[i]);
 		writel(reg, larb->base + SMI_LARB_NONSEC_CON(i));
 	}
 }