1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Loongson IOMMU Driver
4  *
5  * Copyright (C) 2020-2021 Loongson Technology Ltd.
6  * Author:	Lv Chen <lvchen@loongson.cn>
7  *		Wang Yang <wangyang@loongson.cn>
8  */
9 
10 #ifndef LOONGSON_IOMMU_H
11 #define LOONGSON_IOMMU_H
12 
13 #include <linux/device.h>
14 #include <linux/errno.h>
15 #include <linux/io.h>
16 #include <linux/iommu.h>
17 #include <linux/list.h>
18 #include <linux/sizes.h>
19 #include <linux/spinlock.h>
20 #include <asm/addrspace.h>
21 
22 #define IOVA_WIDTH		47
23 
24 /* Bit value definition for I/O PTE fields */
25 #define IOMMU_PTE_PR		(1ULL << 0)	/* Present */
26 #define IOMMU_PTE_HP		(1ULL << 1)	/* HugePage */
27 #define IOMMU_PTE_IR		(1ULL << 2)	/* Readable */
28 #define IOMMU_PTE_IW		(1ULL << 3)	/* Writeable */
29 #define IOMMU_PTE_RW		(IOMMU_PTE_PR | IOMMU_PTE_IR | IOMMU_PTE_IW)
30 
31 #define IOMMU_PTE_PRESENT(pte)	((pte) & IOMMU_PTE_PR)
32 #define IOMMU_PTE_HUGEPAGE(pte)	((pte) & IOMMU_PTE_HP)
33 
34 #define iommu_pt_present(shadow_entry)	((*shadow_entry != 0))
35 
36 /*
37  * shadow_entry using kmalloc to request memory space,
38  * the memory address requested by kmalloc is ARCH_DMA_MINALIGN-aligned,
39  * when the shadow_entry address is not a ARCH_DMA_MINALIGN-aligned
40  * address, we think that shadow_entry store large pages
41  */
42 #define iommu_pt_huge(shd_entry_ptr)	 ((*shd_entry_ptr) & IOMMU_PTE_HP)
43 
44 #define LA_IOMMU_PGSIZE		(SZ_16K | SZ_32M)
45 
46 #define IOMMU_PT_LEVEL0		0x00
47 #define IOMMU_PT_LEVEL1		0x01
48 
49 /* IOMMU page table */
50 #define IOMMU_PAGE_SHIFT	PAGE_SHIFT
51 #define IOMMU_PAGE_SIZE		(_AC(1, UL) << IOMMU_PAGE_SHIFT)
52 #define IOMMU_LEVEL_STRIDE	(IOMMU_PAGE_SHIFT - 3)
53 #define IOMMU_PTRS_PER_LEVEL	(IOMMU_PAGE_SIZE >> 3)
54 #define IOMMU_LEVEL_SHIFT(n)	(((n) * IOMMU_LEVEL_STRIDE) + IOMMU_PAGE_SHIFT)
55 #define IOMMU_LEVEL_SIZE(n)	(_AC(1, UL) << (((n) * IOMMU_LEVEL_STRIDE) + IOMMU_PAGE_SHIFT))
56 #define IOMMU_LEVEL_MASK(n)	(~(IOMMU_LEVEL_SIZE(n) - 1))
57 #define IOMMU_LEVEL_MAX	        DIV_ROUND_UP((IOVA_WIDTH - IOMMU_PAGE_SHIFT), IOMMU_LEVEL_STRIDE)
58 #define IOMMU_PAGE_MASK		(~(IOMMU_PAGE_SIZE - 1))
59 
60 #define IOMMU_HPAGE_SIZE	(1UL << IOMMU_LEVEL_SHIFT(IOMMU_PT_LEVEL1))
61 #define IOMMU_HPAGE_MASK	(~(IOMMU_HPAGE_SIZE - 1))
62 
63 /* Virtio page use size of 16k */
64 #define LA_VIRTIO_PAGE_SHIFT	14
65 #define LA_VIRTIO_PAGE_SIZE	(_AC(1, UL) << LA_VIRTIO_PAGE_SHIFT)
66 #define LA_VIRTIO_PAGE_MASK	(~((1ULL << LA_VIRTIO_PAGE_SHIFT) - 1))
67 
68 /* Bits of iommu map address space field */
69 #define LA_IOMMU_PFN_LO			0x0
70 #define PFN_LO_SHIFT			12
71 #define LA_IOMMU_PFN_HI			0x4
72 #define PFN_HI_MASK			0x3ffff
73 #define LA_IOMMU_VFN_LO			0x8
74 #define VFN_LO_SHIFT			12
75 #define LA_IOMMU_VFN_HI			0xC
76 #define VFN_HI_MASK			0x3ffff
77 
78 /* wired | index | domain | shift */
79 #define LA_IOMMU_WIDS			0x10
80 /* valid | busy | tlbar/aw | cmd */
81 #define LA_IOMMU_VBTC			0x14
82 #define IOMMU_PGTABLE_BUSY		(1 << 16)
83 /* enable |index | valid | domain | bdf */
84 #define LA_IOMMU_EIVDB			0x18
85 /* enable | valid | cmd */
86 #define LA_IOMMU_CMD			0x1C
87 #define LA_IOMMU_PGD0_LO		0x20
88 #define LA_IOMMU_PGD0_HI		0x24
89 #define STEP_PGD			0x8
90 #define STEP_PGD_SHIFT			3
91 #define LA_IOMMU_PGD_LO(domain_id)	\
92 		(LA_IOMMU_PGD0_LO + ((domain_id) << STEP_PGD_SHIFT))
93 #define LA_IOMMU_PGD_HI(domain_id)	\
94 		(LA_IOMMU_PGD0_HI + ((domain_id) << STEP_PGD_SHIFT))
95 
96 #define LA_IOMMU_DIR_CTRL0		0xA0
97 #define LA_IOMMU_DIR_CTRL1		0xA4
98 #define LA_IOMMU_DIR_CTRL(x)		(LA_IOMMU_DIR_CTRL0 + ((x) << 2))
99 
100 #define LA_IOMMU_SAFE_BASE_HI		0xE0
101 #define LA_IOMMU_SAFE_BASE_LO		0xE4
102 #define LA_IOMMU_EX_ADDR_LO		0xE8
103 #define LA_IOMMU_EX_ADDR_HI		0xEC
104 
105 #define LA_IOMMU_PFM_CNT_EN		0x100
106 
107 #define LA_IOMMU_RD_HIT_CNT_0		0x110
108 #define LA_IOMMU_RD_MISS_CNT_O		0x114
109 #define LA_IOMMU_WR_HIT_CNT_0		0x118
110 #define LA_IOMMU_WR_MISS_CNT_0		0x11C
111 #define LA_IOMMU_RD_HIT_CNT_1		0x120
112 #define LA_IOMMU_RD_MISS_CNT_1		0x124
113 #define LA_IOMMU_WR_HIT_CNT_1		0x128
114 #define LA_IOMMU_WR_MISS_CNT_1		0x12C
115 #define LA_IOMMU_RD_HIT_CNT_2		0x130
116 #define LA_IOMMU_RD_MISS_CNT_2		0x134
117 #define LA_IOMMU_WR_HIT_CNT_2		0x138
118 #define LA_IOMMU_WR_MISS_CNT_2		0x13C
119 
120 #define MAX_DOMAIN_ID			16
121 #define MAX_ATTACHED_DEV_ID		16
122 #define MAX_PAGES_NUM			(SZ_128M / IOMMU_PAGE_SIZE)
123 
124 #define iommu_ptable_end(addr, end, level)								\
125 ({	unsigned long __boundary = ((addr) + IOMMU_LEVEL_SIZE(level)) & IOMMU_LEVEL_MASK(level);	\
126 	(__boundary - 1 < (end) - 1) ? __boundary : (end);						\
127 })
128 
129 /* To find an entry in an iommu page table directory */
130 #define iommu_shadow_index(addr, level)		\
131 		(((addr) >> ((level * IOMMU_LEVEL_STRIDE) + IOMMU_PAGE_SHIFT)) & (IOMMU_PTRS_PER_LEVEL - 1))
132 
133 /* IOMMU iommu_table entry */
134 typedef struct { unsigned long iommu_pte; } iommu_pte;
135 
136 typedef struct loongson_iommu {
137 	struct list_head	list;
138 	spinlock_t		domain_bitmap_lock;		/* Lock for domain allocing */
139 	spinlock_t		dom_info_lock;			/* Lock for priv->list */
140 	spinlock_t		pgtable_bitmap_lock;		/* Lock for bitmap of page table */
141 	struct mutex		loongson_iommu_pgtlock;		/* Lock for iommu page table */
142 	void			*domain_bitmap;			/* Bitmap of global domains */
143 	void			*devtable_bitmap;		/* Bitmap of devtable */
144 	void			*pgtable_bitmap;		/* Bitmap of devtable pages for page table */
145 	struct list_head	dom_list;			/* List of all domain privates */
146 	u16 			devid;				/* PCI device id of the IOMMU device */
147 	int			segment;			/* PCI segment# */
148 	void			*membase;
149 	void			*pgtbase;
150 	unsigned long		maxpages;
151 } loongson_iommu;
152 
153 struct loongson_iommu_rlookup_entry
154 {
155 	struct list_head		list;
156 	struct loongson_iommu		**loongson_iommu_rlookup_table;
157 	int				pcisegment;
158 };
159 
160 /* shadow page table entry */
161 typedef struct spt_entry {
162 	unsigned long		*gmem_ptable;		/* gmemory entry address base*/
163 	unsigned long		*shadow_ptable;		/* virtual address base for shadow page */
164 	int			index;			/* index 128M gmem */
165 	int			dirty;
166 	int			present;
167 } spt_entry;
168 
169 typedef struct iommu_info {
170 	struct list_head	list;		/* for loongson_iommu_pri->iommu_devlist */
171 	spt_entry		*shadow_pgd;
172 	struct loongson_iommu	*iommu;
173 	spinlock_t		devlock;	/* priv dev list lock */
174 	struct list_head	dev_list;	/* List of all devices in this domain iommu */
175 	unsigned int		dev_cnt;	/* devices assigned to this domain iommu */
176 	short			id;
177 } iommu_info;
178 
179 /* One vm is equal to a domain, one domain has a priv */
180 typedef struct dom_info {
181 	struct list_head	list;			/* For list of all domains */
182 	struct list_head	iommu_devlist;
183 	struct iommu_domain	domain;
184 	void			*mmio_pgd;		/* 0x10000000~0x8fffffff */
185 	spinlock_t		lock;			/* Lock for priv->iommu_devlist */
186 } dom_info;
187 
188 /* A device for passthrough */
189 struct loongson_iommu_dev_data {
190 	struct list_head	list;		/* for iommu_entry->dev_list */
191 	struct loongson_iommu	*iommu;
192 	iommu_info		*iommu_entry;
193 	unsigned short		bdf;
194 	int			count;
195 	int			index;		/* index in device table */
196 };
197 
iommu_pgt_v2p(loongson_iommu *iommu, void *va)198 static inline unsigned long iommu_pgt_v2p(loongson_iommu *iommu, void *va)
199 {
200 	return (unsigned long)(va - iommu->pgtbase);
201 }
202 
iommu_ptable_offset(unsigned long *table_entry, unsigned long addr, int level)203 static inline unsigned long *iommu_ptable_offset(unsigned long *table_entry,
204 						unsigned long addr, int level)
205 {
206 	return table_entry + iommu_shadow_index(addr, level);
207 }
208 
iommu_shadow_offset(spt_entry *shadow_entry, unsigned long addr, int level)209 static inline unsigned long *iommu_shadow_offset(spt_entry *shadow_entry,
210 						unsigned long addr, int level)
211 {
212 	unsigned long *table_base;
213 
214 	table_base = shadow_entry->shadow_ptable;
215 
216 	return table_base + iommu_shadow_index(addr, level);
217 }
218 
219 #endif	/* LOONGSON_IOMMU_H */
220