/* * Copyright (c) 2014-2015, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of ARM nor the names of its contributors may be used * to endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <arch_helpers.h> #include <assert.h> #include <bakery_lock.h> #include <mmio.h> #include "juno_def.h" #include "juno_private.h" #include "mhu.h" /* SCP MHU secure channel registers */ #define SCP_INTR_S_STAT 0x200 #define SCP_INTR_S_SET 0x208 #define SCP_INTR_S_CLEAR 0x210 /* CPU MHU secure channel registers */ #define CPU_INTR_S_STAT 0x300 #define CPU_INTR_S_SET 0x308 #define CPU_INTR_S_CLEAR 0x310 #if IMAGE_BL31 #if USE_COHERENT_MEM static bakery_lock_t mhu_secure_lock __attribute__ ((section("tzfw_coherent_mem"))); #define LOCK_ARG &mhu_secure_lock #else #define LOCK_ARG JUNO_MHU_BAKERY_ID #endif /*__USE_COHERENT_MEM__ */ #else #define LOCK_ARG /* Locks required only for BL3-1 images */ #endif /* __IMAGE_BL31__ */ /* * Slot 31 is reserved because the MHU hardware uses this register bit to * indicate a non-secure access attempt. The total number of available slots is * therefore 31 [30:0]. */ #define MHU_MAX_SLOT_ID 30 void mhu_secure_message_start(unsigned int slot_id) { assert(slot_id <= MHU_MAX_SLOT_ID); juno_lock_get(LOCK_ARG); /* Make sure any previous command has finished */ while (mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) & (1 << slot_id)) ; } void mhu_secure_message_send(unsigned int slot_id) { assert(slot_id <= MHU_MAX_SLOT_ID); assert(!(mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) & (1 << slot_id))); /* Send command to SCP */ mmio_write_32(MHU_BASE + CPU_INTR_S_SET, 1 << slot_id); } void mhu_secure_message_wait(unsigned int slot_id) { assert(slot_id <= MHU_MAX_SLOT_ID); /* Wait for response from SCP */ while (!(mmio_read_32(MHU_BASE + SCP_INTR_S_STAT) & (1 << slot_id))) ; } void mhu_secure_message_end(unsigned int slot_id) { assert(slot_id <= MHU_MAX_SLOT_ID); /* * Clear any response we got by writing one in the relevant slot bit to * the CLEAR register */ mmio_write_32(MHU_BASE + SCP_INTR_S_CLEAR, 1 << slot_id); juno_lock_release(LOCK_ARG); } void mhu_secure_init(void) { juno_lock_init(LOCK_ARG); /* * The STAT register resets to zero. Ensure it is in the expected state, * as a stale or garbage value would make us think it's a message we've * already sent. */ assert(mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) == 0); }