iommu/amd: Prepare for generic IO page table framework

Add initial hook up code to implement generic IO page table framework.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20201215073705.123786-3-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/Kconfig

@@ -10,6 +10,7 @@ config AMD_IOMMU
 	select IOMMU_API
 	select IOMMU_IOVA
 	select IOMMU_DMA
+	select IOMMU_IO_PGTABLE
 	depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE
 	help
 	  With this option you can enable support for AMD IOMMU hardware in

drivers/iommu/amd/Makefile

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

drivers/iommu/amd/amd_iommu_types.h

@@ -15,6 +15,7 @@
 #include <linux/spinlock.h>
 #include <linux/pci.h>
 #include <linux/irqreturn.h>
+#include <linux/io-pgtable.h>
 
 /*
  * Maximum number of IOMMUs supported
@@ -252,6 +253,19 @@
 
 #define GA_GUEST_NR		0x1
 
+#define IOMMU_IN_ADDR_BIT_SIZE  52
+#define IOMMU_OUT_ADDR_BIT_SIZE 52
+
+/*
+ * This bitmap is used to advertise the page sizes our hardware support
+ * to the IOMMU core, which will then use this information to split
+ * physically contiguous memory regions it is mapping into page sizes
+ * that we support.
+ *
+ * 512GB Pages are not supported due to a hardware bug
+ */
+#define AMD_IOMMU_PGSIZES	((~0xFFFUL) & ~(2ULL << 38))
+
 /* Bit value definition for dte irq remapping fields*/
 #define DTE_IRQ_PHYS_ADDR_MASK	(((1ULL << 45)-1) << 6)
 #define DTE_IRQ_REMAP_INTCTL_MASK	(0x3ULL << 60)
@@ -466,6 +480,26 @@ struct amd_irte_ops;
 
 #define AMD_IOMMU_FLAG_TRANS_PRE_ENABLED      (1 << 0)
 
+#define io_pgtable_to_data(x) \
+	container_of((x), struct amd_io_pgtable, iop)
+
+#define io_pgtable_ops_to_data(x) \
+	io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))
+
+#define io_pgtable_ops_to_domain(x) \
+	container_of(io_pgtable_ops_to_data(x), \
+		     struct protection_domain, iop)
+
+#define io_pgtable_cfg_to_data(x) \
+	container_of((x), struct amd_io_pgtable, pgtbl_cfg)
+
+struct amd_io_pgtable {
+	struct io_pgtable_cfg	pgtbl_cfg;
+	struct io_pgtable	iop;
+	int			mode;
+	u64			*root;
+};
+
 /*
  * This structure contains generic data for  IOMMU protection domains
  * independent of their use.
@@ -474,6 +508,7 @@ struct protection_domain {
 	struct list_head dev_list; /* List of all devices in this domain */
 	struct iommu_domain domain; /* generic domain handle used by
 				       iommu core code */
+	struct amd_io_pgtable iop;
 	spinlock_t lock;	/* mostly used to lock the page table*/
 	u16 id;			/* the domain id written to the device table */
 	atomic64_t pt_root;	/* pgtable root and pgtable mode */

drivers/iommu/amd/io_pgtable.c

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPU-agnostic AMD IO page table allocator.
+ *
+ * Copyright (C) 2020 Advanced Micro Devices, Inc.
+ * Author: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
+ */
+
+#define pr_fmt(fmt)     "AMD-Vi: " fmt
+#define dev_fmt(fmt)    pr_fmt(fmt)
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/io-pgtable.h>
+#include <linux/kernel.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/barrier.h>
+
+#include "amd_iommu_types.h"
+#include "amd_iommu.h"
+
+static void v1_tlb_flush_all(void *cookie)
+{
+}
+
+static void v1_tlb_flush_walk(unsigned long iova, size_t size,
+				  size_t granule, void *cookie)
+{
+}
+
+static void v1_tlb_add_page(struct iommu_iotlb_gather *gather,
+					 unsigned long iova, size_t granule,
+					 void *cookie)
+{
+}
+
+static const struct iommu_flush_ops v1_flush_ops = {
+	.tlb_flush_all	= v1_tlb_flush_all,
+	.tlb_flush_walk = v1_tlb_flush_walk,
+	.tlb_add_page	= v1_tlb_add_page,
+};
+
+/*
+ * ----------------------------------------------------
+ */
+static void v1_free_pgtable(struct io_pgtable *iop)
+{
+}
+
+static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
+{
+	struct amd_io_pgtable *pgtable = io_pgtable_cfg_to_data(cfg);
+
+	cfg->pgsize_bitmap  = AMD_IOMMU_PGSIZES,
+	cfg->ias            = IOMMU_IN_ADDR_BIT_SIZE,
+	cfg->oas            = IOMMU_OUT_ADDR_BIT_SIZE,
+	cfg->tlb            = &v1_flush_ops;
+
+	return &pgtable->iop;
+}
+
+struct io_pgtable_init_fns io_pgtable_amd_iommu_v1_init_fns = {
+	.alloc	= v1_alloc_pgtable,
+	.free	= v1_free_pgtable,
+};

drivers/iommu/amd/iommu.c

@@ -57,16 +57,6 @@
 #define HT_RANGE_START		(0xfd00000000ULL)
 #define HT_RANGE_END		(0xffffffffffULL)
 
-/*
- * This bitmap is used to advertise the page sizes our hardware support
- * to the IOMMU core, which will then use this information to split
- * physically contiguous memory regions it is mapping into page sizes
- * that we support.
- *
- * 512GB Pages are not supported due to a hardware bug
- */
-#define AMD_IOMMU_PGSIZES	((~0xFFFUL) & ~(2ULL << 38))
-
 #define DEFAULT_PGTABLE_LEVEL	PAGE_MODE_3_LEVEL
 
 static DEFINE_SPINLOCK(pd_bitmap_lock);

drivers/iommu/io-pgtable.c

@@ -24,6 +24,9 @@ io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
 	[ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
 #endif
+#ifdef CONFIG_AMD_IOMMU
+	[AMD_IOMMU_V1] = &io_pgtable_amd_iommu_v1_init_fns,
+#endif
 };
 
 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,

include/linux/io-pgtable.h

@@ -15,6 +15,7 @@ enum io_pgtable_fmt {
 	ARM_64_LPAE_S2,
 	ARM_V7S,
 	ARM_MALI_LPAE,
+	AMD_IOMMU_V1,
 	IO_PGTABLE_NUM_FMTS,
 };
 
@@ -251,5 +252,6 @@ extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_amd_iommu_v1_init_fns;
 
 #endif /* __IO_PGTABLE_H */