1 // SPDX-License-Identifier: MIT
3 * The sart code is copied from m1n1 (https://github.com/AsahiLinux/m1n1) and
6 * (C) Copyright 2022 The Asahi Linux Contributors
10 #include <asm/arch/sart.h>
12 #include <linux/bitfield.h>
13 #include <linux/types.h>
17 #define APPLE_SART_MAX_ENTRIES 16
19 /* This is probably a bitfield but the exact meaning of each bit is unknown. */
20 #define APPLE_SART_FLAGS_ALLOW 0xff
22 /* SARTv2 registers */
23 #define APPLE_SART2_CONFIG(idx) (0x00 + 4 * (idx))
24 #define APPLE_SART2_CONFIG_FLAGS GENMASK(31, 24)
25 #define APPLE_SART2_CONFIG_SIZE GENMASK(23, 0)
26 #define APPLE_SART2_CONFIG_SIZE_SHIFT 12
27 #define APPLE_SART2_CONFIG_SIZE_MAX GENMASK(23, 0)
29 #define APPLE_SART2_PADDR(idx) (0x40 + 4 * (idx))
30 #define APPLE_SART2_PADDR_SHIFT 12
32 /* SARTv3 registers */
33 #define APPLE_SART3_CONFIG(idx) (0x00 + 4 * (idx))
35 #define APPLE_SART3_PADDR(idx) (0x40 + 4 * (idx))
36 #define APPLE_SART3_PADDR_SHIFT 12
38 #define APPLE_SART3_SIZE(idx) (0x80 + 4 * (idx))
39 #define APPLE_SART3_SIZE_SHIFT 12
40 #define APPLE_SART3_SIZE_MAX GENMASK(29, 0)
44 u32 protected_entries;
46 void (*get_entry)(struct apple_sart *sart, int index, u8 *flags, void **paddr,
48 bool (*set_entry)(struct apple_sart *sart, int index, u8 flags, void *paddr,
52 static void sart2_get_entry(struct apple_sart *sart, int index, u8 *flags, void **paddr,
55 u32 cfg = readl(sart->base + APPLE_SART2_CONFIG(index));
56 *flags = FIELD_GET(APPLE_SART2_CONFIG_FLAGS, cfg);
57 *size = (size_t)FIELD_GET(APPLE_SART2_CONFIG_SIZE, cfg) << APPLE_SART2_CONFIG_SIZE_SHIFT;
59 ((u64)readl(sart->base + APPLE_SART2_PADDR(index)) << APPLE_SART2_PADDR_SHIFT);
62 static bool sart2_set_entry(struct apple_sart *sart, int index, u8 flags, void *paddr_,
66 u64 paddr = (u64)paddr_;
68 if (size & ((1 << APPLE_SART2_CONFIG_SIZE_SHIFT) - 1))
70 if (paddr & ((1 << APPLE_SART2_PADDR_SHIFT) - 1))
73 size >>= APPLE_SART2_CONFIG_SIZE_SHIFT;
74 paddr >>= APPLE_SART2_PADDR_SHIFT;
76 if (size > APPLE_SART2_CONFIG_SIZE_MAX)
79 cfg = FIELD_PREP(APPLE_SART2_CONFIG_FLAGS, flags);
80 cfg |= FIELD_PREP(APPLE_SART2_CONFIG_SIZE, size);
82 writel(paddr, sart->base + APPLE_SART2_PADDR(index));
83 writel(cfg, sart->base + APPLE_SART2_CONFIG(index));
88 static void sart3_get_entry(struct apple_sart *sart, int index, u8 *flags, void **paddr,
91 *flags = readl(sart->base + APPLE_SART3_CONFIG(index));
92 *size = (size_t)readl(sart->base + APPLE_SART3_SIZE(index)) << APPLE_SART3_SIZE_SHIFT;
94 ((u64)readl(sart->base + APPLE_SART3_PADDR(index)) << APPLE_SART3_PADDR_SHIFT);
97 static bool sart3_set_entry(struct apple_sart *sart, int index, u8 flags, void *paddr_,
100 u64 paddr = (u64)paddr_;
102 if (size & ((1 << APPLE_SART3_SIZE_SHIFT) - 1))
104 if (paddr & ((1 << APPLE_SART3_PADDR_SHIFT) - 1))
107 paddr >>= APPLE_SART3_PADDR_SHIFT;
108 size >>= APPLE_SART3_SIZE_SHIFT;
110 if (size > APPLE_SART3_SIZE_MAX)
113 writel(paddr, sart->base + APPLE_SART3_PADDR(index));
114 writel(size, sart->base + APPLE_SART3_SIZE(index));
115 writel(flags, sart->base + APPLE_SART3_CONFIG(index));
120 struct apple_sart *sart_init(ofnode node)
124 struct apple_sart *sart;
126 base = ofnode_get_addr(node);
127 if (base == FDT_ADDR_T_NONE)
130 if (ofnode_device_is_compatible(node, "apple,t8103-sart")) {
132 } else if (ofnode_device_is_compatible(node, "apple,t6000-sart")) {
135 printf("sart: unknown SART compatible: %sd\n",
136 ofnode_read_string(node, "compatible"));
140 sart = calloc(sizeof(*sart), 1);
146 switch (sart_version) {
148 sart->get_entry = sart2_get_entry;
149 sart->set_entry = sart2_set_entry;
152 sart->get_entry = sart3_get_entry;
153 sart->set_entry = sart3_set_entry;
156 printf("sart: SART has unknown version %d\n", sart_version);
161 sart->protected_entries = 0;
162 for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
167 sart->get_entry(sart, i, &flags, &paddr, &sz);
169 sart->protected_entries |= 1 << i;
175 void sart_free(struct apple_sart *sart)
177 for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
178 if (sart->protected_entries & (1 << i))
180 sart->set_entry(sart, i, 0, NULL, 0);
186 bool sart_add_allowed_region(struct apple_sart *sart, void *paddr, size_t sz)
188 for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
193 if (sart->protected_entries & (1 << i))
196 sart->get_entry(sart, i, &e_flags, &e_paddr, &e_sz);
200 return sart->set_entry(sart, i, APPLE_SART_FLAGS_ALLOW, paddr, sz);
203 printf("sart: no more free entries\n");
207 bool sart_remove_allowed_region(struct apple_sart *sart, void *paddr, size_t sz)
209 for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
214 if (sart->protected_entries & (1 << i))
217 sart->get_entry(sart, i, &e_flags, &e_paddr, &e_sz);
220 if (e_paddr != paddr)
225 return sart->set_entry(sart, i, 0, NULL, 0);
228 printf("sart: could not find entry to be removed\n");