iommu/amd: Initial support for AMD IOMMU v2 page table

Introduce IO page table framework support for AMD IOMMU v2 page table.
This patch implements 4 level page table within iommu amd driver and
supports 4K/2M/1G page sizes.

Signed-off-by: Vasant Hegde <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>

Author: hegdevasant

drivers/iommu/amd/Makefile

@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-$(CONFIG_AMD_IOMMU) += iommu.o init.o quirks.o io_pgtable.o
+obj-$(CONFIG_AMD_IOMMU) += iommu.o init.o quirks.o io_pgtable.o io_pgtable_v2.o
 obj-$(CONFIG_AMD_IOMMU_DEBUGFS) += debugfs.o
 obj-$(CONFIG_AMD_IOMMU_V2) += iommu_v2.o

drivers/iommu/amd/amd_iommu_types.h

@@ -276,6 +276,8 @@
  * 512GB Pages are not supported due to a hardware bug
  */
 #define AMD_IOMMU_PGSIZES	((~0xFFFUL) & ~(2ULL << 38))
+/* 4K, 2MB, 1G page sizes are supported */
+#define AMD_IOMMU_PGSIZES_V2	(PAGE_SIZE | (1ULL << 21) | (1ULL << 30))
 
 /* Bit value definition for dte irq remapping fields*/
 #define DTE_IRQ_PHYS_ADDR_MASK	(((1ULL << 45)-1) << 6)
@@ -526,7 +528,8 @@ struct amd_io_pgtable {
 	struct io_pgtable	iop;
 	int			mode;
 	u64			*root;
-	atomic64_t		pt_root;    /* pgtable root and pgtable mode */
+	atomic64_t		pt_root;	/* pgtable root and pgtable mode */
+	u64			*pgd;		/* v2 pgtable pgd pointer */
 };
 
 /*