/* * Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include #include #include #include #include #include #include #include "se_private.h" /******************************************************************************* * Constants and Macros ******************************************************************************/ #define ERR_STATUS_SW_CLEAR U(0xFFFFFFFF) #define INT_STATUS_SW_CLEAR U(0xFFFFFFFF) #define MAX_TIMEOUT_MS U(100) /* Timeout in 100ms */ #define NUM_SE_REGS_TO_SAVE U(4) /******************************************************************************* * Data structure and global variables ******************************************************************************/ static uint32_t se_regs[NUM_SE_REGS_TO_SAVE]; /* * Check that SE operation has completed after kickoff. * * This function is invoked after an SE operation has been started, * and it checks the following conditions: * * 1. SE_STATUS = IDLE * 2. AHB bus data transfer is complete. * 3. SE_ERR_STATUS is clean. */ static bool tegra_se_is_operation_complete(void) { uint32_t val = 0, timeout = 0, sha_status, aes_status; int32_t ret = 0; bool se_is_busy, txn_has_errors, txn_successful; /* * Poll the status register to check if the operation * completed. */ do { val = tegra_se_read_32(CTX_SAVE_AUTO_STATUS); se_is_busy = !!(val & CTX_SAVE_AUTO_SE_BUSY); /* sleep until SE finishes */ if (se_is_busy) { mdelay(1); timeout++; } } while (se_is_busy && (timeout < MAX_TIMEOUT_MS)); /* any transaction errors? */ txn_has_errors = (tegra_se_read_32(SHA_ERR_STATUS) != 0U) || (tegra_se_read_32(AES0_ERR_STATUS) != 0U); /* transaction successful? */ sha_status = tegra_se_read_32(SHA_INT_STATUS) & SHA_SE_OP_DONE; aes_status = tegra_se_read_32(AES0_INT_STATUS) & AES0_SE_OP_DONE; txn_successful = (sha_status == SHA_SE_OP_DONE) && (aes_status == AES0_SE_OP_DONE); if ((timeout == MAX_TIMEOUT_MS) || txn_has_errors || !txn_successful) { ERROR("%s: Atomic context save operation failed!\n", __func__); ret = -ECANCELED; } return (ret == 0); } /* * Wait for SE engine to be idle and clear any pending interrupts, before * starting the next SE operation. */ static bool tegra_se_is_ready(void) { int32_t ret = 0; uint32_t val = 0, timeout = 0; bool se_is_ready; /* Wait for previous operation to finish */ do { val = tegra_se_read_32(CTX_SAVE_AUTO_STATUS); se_is_ready = (val == CTX_SAVE_AUTO_SE_READY); /* sleep until SE is ready */ if (!se_is_ready) { mdelay(1); timeout++; } } while (!se_is_ready && (timeout < MAX_TIMEOUT_MS)); if (timeout == MAX_TIMEOUT_MS) { ERROR("%s: SE is not ready!\n", __func__); ret = -ETIMEDOUT; } /* Clear any pending interrupts from previous operation */ tegra_se_write_32(AES0_INT_STATUS, INT_STATUS_SW_CLEAR); tegra_se_write_32(AES1_INT_STATUS, INT_STATUS_SW_CLEAR); tegra_se_write_32(RSA_INT_STATUS, INT_STATUS_SW_CLEAR); tegra_se_write_32(SHA_INT_STATUS, INT_STATUS_SW_CLEAR); /* Clear error status for each engine seen from current port */ tegra_se_write_32(AES0_ERR_STATUS, ERR_STATUS_SW_CLEAR); tegra_se_write_32(AES1_ERR_STATUS, ERR_STATUS_SW_CLEAR); tegra_se_write_32(RSA_ERR_STATUS, ERR_STATUS_SW_CLEAR); tegra_se_write_32(SHA_ERR_STATUS, ERR_STATUS_SW_CLEAR); return (ret == 0); } /* * During System Suspend, this handler triggers the hardware context * save operation. */ static int32_t tegra_se_save_context(void) { int32_t ret = -ECANCELED; /* * 1. Ensure all SE Driver including RNG1/PKA1 are shut down. * TSEC/R5s are powergated/idle. All tasks on SE1~SE4, RNG1, * PKA1 are wrapped up. SE0 is ready for use. * 2. Clear interrupt/error in SE0 status register. * 3. Scrub SE0 register to avoid false failure for illegal * configuration. Probably not needed, dependent on HW * implementation. * 4. Check SE is ready for HW CTX_SAVE by polling * SE_CTX_SAVE_AUTO_STATUS.SE_READY. * * Steps 1-4 are executed by tegra_se_is_ready(). * * 5. Issue context save command. * 6. Check SE is busy with CTX_SAVE, the command in step5 was not * dropped for ongoing traffic in any of SE port/engine. * 7. Poll SE register or wait for SE APB interrupt for task completion * a. Polling: Read SE_CTX_SAVE_AUTO_STATUS.BUSY till it reports IDLE * b. Interrupt: After receiving interrupt from SE APB, read * SE_CTX_SAVE_AUTO_STATUS.BUSY till it reports IDLE. * 8. Check AES0 and SHA ERR_STATUS to ensure no error case. * 9. Check AES0 and SHA INT_STATUS to ensure operation has successfully * completed. * * Steps 6-9 are executed by tegra_se_is_operation_complete(). */ if (tegra_se_is_ready()) { /* Issue context save command */ tegra_se_write_32(AES0_OPERATION, SE_OP_CTX_SAVE); /* Wait for operation to finish */ if (tegra_se_is_operation_complete()) { ret = 0; } } return ret; } /* * Handler to power down the SE hardware blocks - SE, RNG1 and PKA1. This * needs to be called only during System Suspend. */ int32_t tegra_se_suspend(void) { int32_t ret = 0; /* save SE registers */ se_regs[0] = mmio_read_32(TEGRA_SE0_BASE + SE0_MUTEX_WATCHDOG_NS_LIMIT); se_regs[1] = mmio_read_32(TEGRA_SE0_BASE + SE0_AES0_ENTROPY_SRC_AGE_CTRL); se_regs[2] = mmio_read_32(TEGRA_RNG1_BASE + RNG1_MUTEX_WATCHDOG_NS_LIMIT); se_regs[3] = mmio_read_32(TEGRA_PKA1_BASE + PKA1_MUTEX_WATCHDOG_NS_LIMIT); /* Save SE context. The BootROM restores it during System Resume */ ret = tegra_se_save_context(); if (ret != 0) { ERROR("%s: context save failed (%d)\n", __func__, ret); } return ret; } /* * Handler to power up the SE hardware block(s) during System Resume. */ void tegra_se_resume(void) { /* * When TZ takes over after System Resume, TZ should first reconfigure * SE_MUTEX_WATCHDOG_NS_LIMIT, PKA1_MUTEX_WATCHDOG_NS_LIMIT, * RNG1_MUTEX_WATCHDOG_NS_LIMIT and SE_ENTROPY_SRC_AGE_CTRL before * other operations. */ mmio_write_32(TEGRA_SE0_BASE + SE0_MUTEX_WATCHDOG_NS_LIMIT, se_regs[0]); mmio_write_32(TEGRA_SE0_BASE + SE0_AES0_ENTROPY_SRC_AGE_CTRL, se_regs[1]); mmio_write_32(TEGRA_RNG1_BASE + RNG1_MUTEX_WATCHDOG_NS_LIMIT, se_regs[2]); mmio_write_32(TEGRA_PKA1_BASE + PKA1_MUTEX_WATCHDOG_NS_LIMIT, se_regs[3]); }