1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Guest ITS library, generously donated by drivers/irqchip/irq-gic-v3-its.c 4 * over in the kernel tree. 5 */ 6 7 #include <linux/kvm.h> 8 #include <linux/sizes.h> 9 #include <asm/kvm_para.h> 10 #include <asm/kvm.h> 11 12 #include "kvm_util.h" 13 #include "vgic.h" 14 #include "gic.h" 15 #include "gic_v3.h" 16 #include "processor.h" 17 18 #define GITS_COLLECTION_TARGET_SHIFT 16 19 20 static u64 its_read_u64(unsigned long offset) 21 { 22 return readq_relaxed(GITS_BASE_GVA + offset); 23 } 24 25 static void its_write_u64(unsigned long offset, u64 val) 26 { 27 writeq_relaxed(val, GITS_BASE_GVA + offset); 28 } 29 30 static u32 its_read_u32(unsigned long offset) 31 { 32 return readl_relaxed(GITS_BASE_GVA + offset); 33 } 34 35 static void its_write_u32(unsigned long offset, u32 val) 36 { 37 writel_relaxed(val, GITS_BASE_GVA + offset); 38 } 39 40 static unsigned long its_find_baser(unsigned int type) 41 { 42 int i; 43 44 for (i = 0; i < GITS_BASER_NR_REGS; i++) { 45 u64 baser; 46 unsigned long offset = GITS_BASER + (i * sizeof(baser)); 47 48 baser = its_read_u64(offset); 49 if (GITS_BASER_TYPE(baser) == type) 50 return offset; 51 } 52 53 GUEST_FAIL("Couldn't find an ITS BASER of type %u", type); 54 return -1; 55 } 56 57 static void its_install_table(unsigned int type, vm_paddr_t base, size_t size) 58 { 59 unsigned long offset = its_find_baser(type); 60 u64 baser; 61 62 baser = ((size / SZ_64K) - 1) | 63 GITS_BASER_PAGE_SIZE_64K | 64 GITS_BASER_InnerShareable | 65 base | 66 GITS_BASER_RaWaWb | 67 GITS_BASER_VALID; 68 69 its_write_u64(offset, baser); 70 } 71 72 static void its_install_cmdq(vm_paddr_t base, size_t size) 73 { 74 u64 cbaser; 75 76 cbaser = ((size / SZ_4K) - 1) | 77 GITS_CBASER_InnerShareable | 78 base | 79 GITS_CBASER_RaWaWb | 80 GITS_CBASER_VALID; 81 82 its_write_u64(GITS_CBASER, cbaser); 83 } 84 85 void its_init(vm_paddr_t coll_tbl, size_t coll_tbl_sz, 86 vm_paddr_t device_tbl, size_t device_tbl_sz, 87 vm_paddr_t cmdq, size_t cmdq_size) 88 { 89 u32 ctlr; 90 91 its_install_table(GITS_BASER_TYPE_COLLECTION, coll_tbl, coll_tbl_sz); 92 its_install_table(GITS_BASER_TYPE_DEVICE, device_tbl, device_tbl_sz); 93 its_install_cmdq(cmdq, cmdq_size); 94 95 ctlr = its_read_u32(GITS_CTLR); 96 ctlr |= GITS_CTLR_ENABLE; 97 its_write_u32(GITS_CTLR, ctlr); 98 } 99 100 struct its_cmd_block { 101 union { 102 u64 raw_cmd[4]; 103 __le64 raw_cmd_le[4]; 104 }; 105 }; 106 107 static inline void its_fixup_cmd(struct its_cmd_block *cmd) 108 { 109 /* Let's fixup BE commands */ 110 cmd->raw_cmd_le[0] = cpu_to_le64(cmd->raw_cmd[0]); 111 cmd->raw_cmd_le[1] = cpu_to_le64(cmd->raw_cmd[1]); 112 cmd->raw_cmd_le[2] = cpu_to_le64(cmd->raw_cmd[2]); 113 cmd->raw_cmd_le[3] = cpu_to_le64(cmd->raw_cmd[3]); 114 } 115 116 static void its_mask_encode(u64 *raw_cmd, u64 val, int h, int l) 117 { 118 u64 mask = GENMASK_ULL(h, l); 119 *raw_cmd &= ~mask; 120 *raw_cmd |= (val << l) & mask; 121 } 122 123 static void its_encode_cmd(struct its_cmd_block *cmd, u8 cmd_nr) 124 { 125 its_mask_encode(&cmd->raw_cmd[0], cmd_nr, 7, 0); 126 } 127 128 static void its_encode_devid(struct its_cmd_block *cmd, u32 devid) 129 { 130 its_mask_encode(&cmd->raw_cmd[0], devid, 63, 32); 131 } 132 133 static void its_encode_event_id(struct its_cmd_block *cmd, u32 id) 134 { 135 its_mask_encode(&cmd->raw_cmd[1], id, 31, 0); 136 } 137 138 static void its_encode_phys_id(struct its_cmd_block *cmd, u32 phys_id) 139 { 140 its_mask_encode(&cmd->raw_cmd[1], phys_id, 63, 32); 141 } 142 143 static void its_encode_size(struct its_cmd_block *cmd, u8 size) 144 { 145 its_mask_encode(&cmd->raw_cmd[1], size, 4, 0); 146 } 147 148 static void its_encode_itt(struct its_cmd_block *cmd, u64 itt_addr) 149 { 150 its_mask_encode(&cmd->raw_cmd[2], itt_addr >> 8, 51, 8); 151 } 152 153 static void its_encode_valid(struct its_cmd_block *cmd, int valid) 154 { 155 its_mask_encode(&cmd->raw_cmd[2], !!valid, 63, 63); 156 } 157 158 static void its_encode_target(struct its_cmd_block *cmd, u64 target_addr) 159 { 160 its_mask_encode(&cmd->raw_cmd[2], target_addr >> 16, 51, 16); 161 } 162 163 static void its_encode_collection(struct its_cmd_block *cmd, u16 col) 164 { 165 its_mask_encode(&cmd->raw_cmd[2], col, 15, 0); 166 } 167 168 static u64 procnum_to_rdbase(u32 vcpu_id) 169 { 170 return vcpu_id << GITS_COLLECTION_TARGET_SHIFT; 171 } 172 173 #define GITS_CMDQ_POLL_ITERATIONS 0 174 175 static void its_send_cmd(void *cmdq_base, struct its_cmd_block *cmd) 176 { 177 u64 cwriter = its_read_u64(GITS_CWRITER); 178 struct its_cmd_block *dst = cmdq_base + cwriter; 179 u64 cbaser = its_read_u64(GITS_CBASER); 180 size_t cmdq_size; 181 u64 next; 182 int i; 183 184 cmdq_size = ((cbaser & 0xFF) + 1) * SZ_4K; 185 186 its_fixup_cmd(cmd); 187 188 WRITE_ONCE(*dst, *cmd); 189 dsb(ishst); 190 next = (cwriter + sizeof(*cmd)) % cmdq_size; 191 its_write_u64(GITS_CWRITER, next); 192 193 /* 194 * Polling isn't necessary considering KVM's ITS emulation at the time 195 * of writing this, as the CMDQ is processed synchronously after a write 196 * to CWRITER. 197 */ 198 for (i = 0; its_read_u64(GITS_CREADR) != next; i++) { 199 __GUEST_ASSERT(i < GITS_CMDQ_POLL_ITERATIONS, 200 "ITS didn't process command at offset %lu after %d iterations\n", 201 cwriter, i); 202 203 cpu_relax(); 204 } 205 } 206 207 void its_send_mapd_cmd(void *cmdq_base, u32 device_id, vm_paddr_t itt_base, 208 size_t itt_size, bool valid) 209 { 210 struct its_cmd_block cmd = {}; 211 212 its_encode_cmd(&cmd, GITS_CMD_MAPD); 213 its_encode_devid(&cmd, device_id); 214 its_encode_size(&cmd, ilog2(itt_size) - 1); 215 its_encode_itt(&cmd, itt_base); 216 its_encode_valid(&cmd, valid); 217 218 its_send_cmd(cmdq_base, &cmd); 219 } 220 221 void its_send_mapc_cmd(void *cmdq_base, u32 vcpu_id, u32 collection_id, bool valid) 222 { 223 struct its_cmd_block cmd = {}; 224 225 its_encode_cmd(&cmd, GITS_CMD_MAPC); 226 its_encode_collection(&cmd, collection_id); 227 its_encode_target(&cmd, procnum_to_rdbase(vcpu_id)); 228 its_encode_valid(&cmd, valid); 229 230 its_send_cmd(cmdq_base, &cmd); 231 } 232 233 void its_send_mapti_cmd(void *cmdq_base, u32 device_id, u32 event_id, 234 u32 collection_id, u32 intid) 235 { 236 struct its_cmd_block cmd = {}; 237 238 its_encode_cmd(&cmd, GITS_CMD_MAPTI); 239 its_encode_devid(&cmd, device_id); 240 its_encode_event_id(&cmd, event_id); 241 its_encode_phys_id(&cmd, intid); 242 its_encode_collection(&cmd, collection_id); 243 244 its_send_cmd(cmdq_base, &cmd); 245 } 246 247 void its_send_invall_cmd(void *cmdq_base, u32 collection_id) 248 { 249 struct its_cmd_block cmd = {}; 250 251 its_encode_cmd(&cmd, GITS_CMD_INVALL); 252 its_encode_collection(&cmd, collection_id); 253 254 its_send_cmd(cmdq_base, &cmd); 255 } 256