1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved. 4 * Copyright (c) 2019-2020, Linaro Limited 5 */ 6 #include <assert.h> 7 #include <drivers/scmi-msg.h> 8 #include <drivers/scmi.h> 9 #include <io.h> 10 #include <kernel/misc.h> 11 #include <kernel/panic.h> 12 #include <kernel/spinlock.h> 13 #include <stdbool.h> 14 #include <stdint.h> 15 #include <string.h> 16 #include <trace.h> 17 #include <util.h> 18 19 #include "common.h" 20 21 /* Legacy SMT/SCMI messages are 128 bytes at most including SMT header */ 22 #define SCMI_PLAYLOAD_MAX 92 23 #define SCMI_PLAYLOAD_U32_MAX (SCMI_PLAYLOAD_MAX / sizeof(uint32_t)) 24 25 /** 26 * struct smt_header - SMT formatted header for SMT base shared memory transfer 27 * 28 * @status: Bit flags, see SMT_STATUS_* 29 * @flags: Bit flags, see SMT_FLAG_* 30 * @length: Byte size of message payload (variable) + ::message_header (32bit) 31 * payload: SCMI message payload data 32 */ 33 struct smt_header { 34 uint32_t reserved0; 35 uint32_t status; 36 uint64_t reserved1; 37 uint32_t flags; 38 uint32_t length; /* message_header + payload */ 39 uint32_t message_header; 40 uint32_t payload[]; 41 }; 42 43 /* Flag set in smt_header::status when SMT does not contain pending message */ 44 #define SMT_STATUS_FREE BIT(0) 45 /* Flag set in smt_header::status when SMT reports an error */ 46 #define SMT_STATUS_ERROR BIT(1) 47 48 /* Flag set in smt_header::flags when SMT uses interrupts */ 49 #define SMT_FLAG_INTR_ENABLED BIT(1) 50 51 /* Bit fields packed in smt_header::message_header */ 52 #define SMT_MSG_ID_MASK GENMASK_32(7, 0) 53 #define SMT_HDR_MSG_ID(_hdr) ((_hdr) & SMT_MSG_ID_MASK) 54 55 #define SMT_MSG_TYPE_MASK GENMASK_32(9, 8) 56 #define SMT_HDR_TYPE_ID(_hdr) (((_hdr) & SMT_MSG_TYPE_MASK) >> 8) 57 58 #define SMT_MSG_PROT_ID_MASK GENMASK_32(17, 10) 59 #define SMT_HDR_PROT_ID(_hdr) (((_hdr) & SMT_MSG_PROT_ID_MASK) >> 10) 60 61 /* SMP protection on channel access */ 62 static unsigned int smt_channels_lock; 63 64 /* If channel is not busy, set busy and return true, otherwise return false */ 65 static bool channel_set_busy(struct scmi_msg_channel *chan) 66 { 67 uint32_t exceptions = cpu_spin_lock_xsave(&smt_channels_lock); 68 bool channel_is_busy = chan->busy; 69 70 if (!channel_is_busy) 71 chan->busy = true; 72 73 cpu_spin_unlock_xrestore(&smt_channels_lock, exceptions); 74 75 return !channel_is_busy; 76 } 77 78 static void channel_release_busy(struct scmi_msg_channel *chan) 79 { 80 chan->busy = false; 81 } 82 83 static struct smt_header *channel_to_smt_hdr(struct scmi_msg_channel *chan) 84 { 85 return (struct smt_header *)io_pa_or_va(&chan->shm_addr); 86 } 87 88 /* 89 * Creates a SCMI message instance in secure memory and push it in the SCMI 90 * message drivers. Message structure contains SCMI protocol meta-data and 91 * references to input payload in secure memory and output message buffer 92 * in shared memory. 93 */ 94 static void scmi_proccess_smt(unsigned int agent_id, uint32_t *payload_buf) 95 { 96 struct scmi_msg_channel *chan = NULL; 97 struct smt_header *smt_hdr = NULL; 98 size_t in_payload_size = 0; 99 uint32_t smt_status = 0; 100 struct scmi_msg msg = { }; 101 bool error = true; 102 103 chan = plat_scmi_get_channel(agent_id); 104 if (!chan) 105 return; 106 107 smt_hdr = channel_to_smt_hdr(chan); 108 assert(smt_hdr); 109 110 smt_status = READ_ONCE(smt_hdr->status); 111 112 if (!channel_set_busy(chan)) { 113 DMSG("SCMI channel %u busy", agent_id); 114 goto out; 115 } 116 117 in_payload_size = READ_ONCE(smt_hdr->length) - 118 sizeof(smt_hdr->message_header); 119 120 if (in_payload_size > SCMI_PLAYLOAD_MAX) { 121 DMSG("SCMI payload too big %u", in_payload_size); 122 goto out; 123 } 124 125 if (smt_status & (SMT_STATUS_ERROR | SMT_STATUS_FREE)) { 126 DMSG("SCMI channel bad status 0x%x", 127 smt_hdr->status & (SMT_STATUS_ERROR | SMT_STATUS_FREE)); 128 goto out; 129 } 130 131 /* Fill message */ 132 msg.in = (char *)payload_buf; 133 msg.in_size = in_payload_size; 134 msg.out = (char *)smt_hdr->payload; 135 msg.out_size = chan->shm_size - sizeof(*smt_hdr); 136 137 assert(msg.out && msg.out_size >= sizeof(int32_t)); 138 139 /* Here the payload is copied in secure memory */ 140 memcpy(msg.in, smt_hdr->payload, in_payload_size); 141 142 msg.protocol_id = SMT_HDR_PROT_ID(smt_hdr->message_header); 143 msg.message_id = SMT_HDR_MSG_ID(smt_hdr->message_header); 144 msg.agent_id = agent_id; 145 146 scmi_process_message(&msg); 147 148 /* Update message length with the length of the response message */ 149 smt_hdr->length = msg.out_size_out + sizeof(smt_hdr->message_header); 150 151 channel_release_busy(chan); 152 error = false; 153 154 out: 155 if (error) { 156 DMSG("SCMI error"); 157 smt_hdr->status |= SMT_STATUS_ERROR | SMT_STATUS_FREE; 158 } else { 159 smt_hdr->status |= SMT_STATUS_FREE; 160 } 161 } 162 163 #ifdef CFG_SCMI_MSG_SMT_FASTCALL_ENTRY 164 /* Provision input message payload buffers for fastcall SMC context entries */ 165 static uint32_t fast_smc_payload[CFG_TEE_CORE_NB_CORE][SCMI_PLAYLOAD_U32_MAX]; 166 167 void scmi_smt_fastcall_smc_entry(unsigned int agent_id) 168 { 169 scmi_proccess_smt(agent_id, fast_smc_payload[get_core_pos()]); 170 } 171 #endif 172 173 #ifdef CFG_SCMI_MSG_SMT_INTERRUPT_ENTRY 174 /* Provision input message payload buffers for fastcall SMC context entries */ 175 static uint32_t interrupt_payload[CFG_TEE_CORE_NB_CORE][SCMI_PLAYLOAD_U32_MAX]; 176 177 void scmi_smt_interrupt_entry(unsigned int agent_id) 178 { 179 scmi_proccess_smt(agent_id, interrupt_payload[get_core_pos()]); 180 } 181 #endif 182 183 #ifdef CFG_SCMI_MSG_SMT_THREAD_ENTRY 184 /* Provision input message payload buffers for fastcall SMC context entries */ 185 static uint32_t threaded_payload[CFG_NUM_THREADS][SCMI_PLAYLOAD_U32_MAX]; 186 187 void scmi_smt_threaded_entry(unsigned int agent_id) 188 { 189 assert(plat_scmi_get_channel(agent_id)->threaded); 190 191 scmi_proccess_smt(agent_id, threaded_payload[thread_get_id()]); 192 } 193 #endif 194 195 /* Init a SMT header for a shared memory buffer: state it a free/no-error */ 196 void scmi_smt_init_agent_channel(struct scmi_msg_channel *chan) 197 { 198 COMPILE_TIME_ASSERT(SCMI_PLAYLOAD_MAX + sizeof(struct smt_header) <= 199 SMT_BUF_SLOT_SIZE); 200 201 if (chan) { 202 struct smt_header *smt_header = channel_to_smt_hdr(chan); 203 204 if (smt_header) { 205 memset(smt_header, 0, sizeof(*smt_header)); 206 smt_header->status = SMT_STATUS_FREE; 207 208 return; 209 } 210 } 211 212 panic(); 213 } 214