From 33960acccfbd7f24d443cb3d0312ac28abe62bae Mon Sep 17 00:00:00 2001 From: Rijo Thomas Date: Wed, 4 Dec 2019 11:49:02 +0530 Subject: crypto: ccp - add TEE support for Raven Ridge Adds a PCI device entry for Raven Ridge. Raven Ridge is an APU with a dedicated AMD Secure Processor having Trusted Execution Environment (TEE) support. The TEE provides a secure environment for running Trusted Applications (TAs) which implement security-sensitive parts of a feature. This patch configures AMD Secure Processor's TEE interface by initializing a ring buffer (shared memory between Rich OS and Trusted OS) which can hold multiple command buffer entries. The TEE interface is facilitated by a set of CPU to PSP mailbox registers. The next patch will address how commands are submitted to the ring buffer. Cc: Jens Wiklander Cc: Tom Lendacky Cc: Ard Biesheuvel Co-developed-by: Devaraj Rangasamy Signed-off-by: Devaraj Rangasamy Signed-off-by: Rijo Thomas Acked-by: Gary R Hook Signed-off-by: Herbert Xu --- drivers/crypto/ccp/tee-dev.c | 238 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 drivers/crypto/ccp/tee-dev.c (limited to 'drivers/crypto/ccp/tee-dev.c') diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c new file mode 100644 index 000000000000..ccbc2ce59d51 --- /dev/null +++ b/drivers/crypto/ccp/tee-dev.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: MIT +/* + * AMD Trusted Execution Environment (TEE) interface + * + * Author: Rijo Thomas + * Author: Devaraj Rangasamy + * + * Copyright 2019 Advanced Micro Devices, Inc. + */ + +#include +#include +#include +#include +#include +#include + +#include "psp-dev.h" +#include "tee-dev.h" + +static bool psp_dead; + +static int tee_alloc_ring(struct psp_tee_device *tee, int ring_size) +{ + struct ring_buf_manager *rb_mgr = &tee->rb_mgr; + void *start_addr; + + if (!ring_size) + return -EINVAL; + + /* We need actual physical address instead of DMA address, since + * Trusted OS running on AMD Secure Processor will map this region + */ + start_addr = (void *)__get_free_pages(GFP_KERNEL, get_order(ring_size)); + if (!start_addr) + return -ENOMEM; + + rb_mgr->ring_start = start_addr; + rb_mgr->ring_size = ring_size; + rb_mgr->ring_pa = __psp_pa(start_addr); + + return 0; +} + +static void tee_free_ring(struct psp_tee_device *tee) +{ + struct ring_buf_manager *rb_mgr = &tee->rb_mgr; + + if (!rb_mgr->ring_start) + return; + + free_pages((unsigned long)rb_mgr->ring_start, + get_order(rb_mgr->ring_size)); + + rb_mgr->ring_start = NULL; + rb_mgr->ring_size = 0; + rb_mgr->ring_pa = 0; +} + +static int tee_wait_cmd_poll(struct psp_tee_device *tee, unsigned int timeout, + unsigned int *reg) +{ + /* ~10ms sleep per loop => nloop = timeout * 100 */ + int nloop = timeout * 100; + + while (--nloop) { + *reg = ioread32(tee->io_regs + tee->vdata->cmdresp_reg); + if (*reg & PSP_CMDRESP_RESP) + return 0; + + usleep_range(10000, 10100); + } + + dev_err(tee->dev, "tee: command timed out, disabling PSP\n"); + psp_dead = true; + + return -ETIMEDOUT; +} + +static +struct tee_init_ring_cmd *tee_alloc_cmd_buffer(struct psp_tee_device *tee) +{ + struct tee_init_ring_cmd *cmd; + + cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); + if (!cmd) + return NULL; + + cmd->hi_addr = upper_32_bits(tee->rb_mgr.ring_pa); + cmd->low_addr = lower_32_bits(tee->rb_mgr.ring_pa); + cmd->size = tee->rb_mgr.ring_size; + + dev_dbg(tee->dev, "tee: ring address: high = 0x%x low = 0x%x size = %u\n", + cmd->hi_addr, cmd->low_addr, cmd->size); + + return cmd; +} + +static inline void tee_free_cmd_buffer(struct tee_init_ring_cmd *cmd) +{ + kfree(cmd); +} + +static int tee_init_ring(struct psp_tee_device *tee) +{ + int ring_size = MAX_RING_BUFFER_ENTRIES * sizeof(struct tee_ring_cmd); + struct tee_init_ring_cmd *cmd; + phys_addr_t cmd_buffer; + unsigned int reg; + int ret; + + BUILD_BUG_ON(sizeof(struct tee_ring_cmd) != 1024); + + ret = tee_alloc_ring(tee, ring_size); + if (ret) { + dev_err(tee->dev, "tee: ring allocation failed %d\n", ret); + return ret; + } + + tee->rb_mgr.wptr = 0; + + cmd = tee_alloc_cmd_buffer(tee); + if (!cmd) { + tee_free_ring(tee); + return -ENOMEM; + } + + cmd_buffer = __psp_pa((void *)cmd); + + /* Send command buffer details to Trusted OS by writing to + * CPU-PSP message registers + */ + + iowrite32(lower_32_bits(cmd_buffer), + tee->io_regs + tee->vdata->cmdbuff_addr_lo_reg); + iowrite32(upper_32_bits(cmd_buffer), + tee->io_regs + tee->vdata->cmdbuff_addr_hi_reg); + iowrite32(TEE_RING_INIT_CMD, + tee->io_regs + tee->vdata->cmdresp_reg); + + ret = tee_wait_cmd_poll(tee, TEE_DEFAULT_TIMEOUT, ®); + if (ret) { + dev_err(tee->dev, "tee: ring init command timed out\n"); + tee_free_ring(tee); + goto free_buf; + } + + if (reg & PSP_CMDRESP_ERR_MASK) { + dev_err(tee->dev, "tee: ring init command failed (%#010x)\n", + reg & PSP_CMDRESP_ERR_MASK); + tee_free_ring(tee); + ret = -EIO; + } + +free_buf: + tee_free_cmd_buffer(cmd); + + return ret; +} + +static void tee_destroy_ring(struct psp_tee_device *tee) +{ + unsigned int reg; + int ret; + + if (!tee->rb_mgr.ring_start) + return; + + if (psp_dead) + goto free_ring; + + iowrite32(TEE_RING_DESTROY_CMD, + tee->io_regs + tee->vdata->cmdresp_reg); + + ret = tee_wait_cmd_poll(tee, TEE_DEFAULT_TIMEOUT, ®); + if (ret) { + dev_err(tee->dev, "tee: ring destroy command timed out\n"); + } else if (reg & PSP_CMDRESP_ERR_MASK) { + dev_err(tee->dev, "tee: ring destroy command failed (%#010x)\n", + reg & PSP_CMDRESP_ERR_MASK); + } + +free_ring: + tee_free_ring(tee); +} + +int tee_dev_init(struct psp_device *psp) +{ + struct device *dev = psp->dev; + struct psp_tee_device *tee; + int ret; + + ret = -ENOMEM; + tee = devm_kzalloc(dev, sizeof(*tee), GFP_KERNEL); + if (!tee) + goto e_err; + + psp->tee_data = tee; + + tee->dev = dev; + tee->psp = psp; + + tee->io_regs = psp->io_regs; + + tee->vdata = (struct tee_vdata *)psp->vdata->tee; + if (!tee->vdata) { + ret = -ENODEV; + dev_err(dev, "tee: missing driver data\n"); + goto e_err; + } + + ret = tee_init_ring(tee); + if (ret) { + dev_err(dev, "tee: failed to init ring buffer\n"); + goto e_err; + } + + dev_notice(dev, "tee enabled\n"); + + return 0; + +e_err: + psp->tee_data = NULL; + + dev_notice(dev, "tee initialization failed\n"); + + return ret; +} + +void tee_dev_destroy(struct psp_device *psp) +{ + struct psp_tee_device *tee = psp->tee_data; + + if (!tee) + return; + + tee_destroy_ring(tee); +} -- cgit v1.2.3-70-g09d2 From 632b0b5301f67ce54b840d55950707003a489151 Mon Sep 17 00:00:00 2001 From: Rijo Thomas Date: Wed, 4 Dec 2019 11:49:03 +0530 Subject: crypto: ccp - provide in-kernel API to submit TEE commands Extend the functionality of AMD Secure Processor (SP) driver by providing an in-kernel API to submit commands to TEE ring buffer for processing by Trusted OS running on AMD Secure Processor. Following TEE commands are supported by Trusted OS: * TEE_CMD_ID_LOAD_TA : Load Trusted Application (TA) binary into TEE environment * TEE_CMD_ID_UNLOAD_TA : Unload TA binary from TEE environment * TEE_CMD_ID_OPEN_SESSION : Open session with loaded TA * TEE_CMD_ID_CLOSE_SESSION : Close session with loaded TA * TEE_CMD_ID_INVOKE_CMD : Invoke a command with loaded TA * TEE_CMD_ID_MAP_SHARED_MEM : Map shared memory * TEE_CMD_ID_UNMAP_SHARED_MEM : Unmap shared memory Linux AMD-TEE driver will use this API to submit command buffers for processing in Trusted Execution Environment. The AMD-TEE driver shall be introduced in a separate patch. Cc: Jens Wiklander Cc: Tom Lendacky Cc: Ard Biesheuvel Co-developed-by: Devaraj Rangasamy Signed-off-by: Devaraj Rangasamy Signed-off-by: Rijo Thomas Acked-by: Gary R Hook Signed-off-by: Herbert Xu --- drivers/crypto/ccp/tee-dev.c | 126 +++++++++++++++++++++++++++++++++++++++++++ drivers/crypto/ccp/tee-dev.h | 1 + include/linux/psp-tee.h | 73 +++++++++++++++++++++++++ 3 files changed, 200 insertions(+) create mode 100644 include/linux/psp-tee.h (limited to 'drivers/crypto/ccp/tee-dev.c') diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c index ccbc2ce59d51..555c8a7c5684 100644 --- a/drivers/crypto/ccp/tee-dev.c +++ b/drivers/crypto/ccp/tee-dev.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "psp-dev.h" #include "tee-dev.h" @@ -38,6 +39,7 @@ static int tee_alloc_ring(struct psp_tee_device *tee, int ring_size) rb_mgr->ring_start = start_addr; rb_mgr->ring_size = ring_size; rb_mgr->ring_pa = __psp_pa(start_addr); + mutex_init(&rb_mgr->mutex); return 0; } @@ -55,6 +57,7 @@ static void tee_free_ring(struct psp_tee_device *tee) rb_mgr->ring_start = NULL; rb_mgr->ring_size = 0; rb_mgr->ring_pa = 0; + mutex_destroy(&rb_mgr->mutex); } static int tee_wait_cmd_poll(struct psp_tee_device *tee, unsigned int timeout, @@ -236,3 +239,126 @@ void tee_dev_destroy(struct psp_device *psp) tee_destroy_ring(tee); } + +static int tee_submit_cmd(struct psp_tee_device *tee, enum tee_cmd_id cmd_id, + void *buf, size_t len, struct tee_ring_cmd **resp) +{ + struct tee_ring_cmd *cmd; + u32 rptr, wptr; + int nloop = 1000, ret = 0; + + *resp = NULL; + + mutex_lock(&tee->rb_mgr.mutex); + + wptr = tee->rb_mgr.wptr; + + /* Check if ring buffer is full */ + do { + rptr = ioread32(tee->io_regs + tee->vdata->ring_rptr_reg); + + if (!(wptr + sizeof(struct tee_ring_cmd) == rptr)) + break; + + dev_info(tee->dev, "tee: ring buffer full. rptr = %u wptr = %u\n", + rptr, wptr); + + /* Wait if ring buffer is full */ + mutex_unlock(&tee->rb_mgr.mutex); + schedule_timeout_interruptible(msecs_to_jiffies(10)); + mutex_lock(&tee->rb_mgr.mutex); + + } while (--nloop); + + if (!nloop && (wptr + sizeof(struct tee_ring_cmd) == rptr)) { + dev_err(tee->dev, "tee: ring buffer full. rptr = %u wptr = %u\n", + rptr, wptr); + ret = -EBUSY; + goto unlock; + } + + /* Pointer to empty data entry in ring buffer */ + cmd = (struct tee_ring_cmd *)(tee->rb_mgr.ring_start + wptr); + + /* Write command data into ring buffer */ + cmd->cmd_id = cmd_id; + cmd->cmd_state = TEE_CMD_STATE_INIT; + memset(&cmd->buf[0], 0, sizeof(cmd->buf)); + memcpy(&cmd->buf[0], buf, len); + + /* Update local copy of write pointer */ + tee->rb_mgr.wptr += sizeof(struct tee_ring_cmd); + if (tee->rb_mgr.wptr >= tee->rb_mgr.ring_size) + tee->rb_mgr.wptr = 0; + + /* Trigger interrupt to Trusted OS */ + iowrite32(tee->rb_mgr.wptr, tee->io_regs + tee->vdata->ring_wptr_reg); + + /* The response is provided by Trusted OS in same + * location as submitted data entry within ring buffer. + */ + *resp = cmd; + +unlock: + mutex_unlock(&tee->rb_mgr.mutex); + + return ret; +} + +static int tee_wait_cmd_completion(struct psp_tee_device *tee, + struct tee_ring_cmd *resp, + unsigned int timeout) +{ + /* ~5ms sleep per loop => nloop = timeout * 200 */ + int nloop = timeout * 200; + + while (--nloop) { + if (resp->cmd_state == TEE_CMD_STATE_COMPLETED) + return 0; + + usleep_range(5000, 5100); + } + + dev_err(tee->dev, "tee: command 0x%x timed out, disabling PSP\n", + resp->cmd_id); + + psp_dead = true; + + return -ETIMEDOUT; +} + +int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len, + u32 *status) +{ + struct psp_device *psp = psp_get_master_device(); + struct psp_tee_device *tee; + struct tee_ring_cmd *resp; + int ret; + + if (!buf || !status || !len || len > sizeof(resp->buf)) + return -EINVAL; + + *status = 0; + + if (!psp || !psp->tee_data) + return -ENODEV; + + if (psp_dead) + return -EBUSY; + + tee = psp->tee_data; + + ret = tee_submit_cmd(tee, cmd_id, buf, len, &resp); + if (ret) + return ret; + + ret = tee_wait_cmd_completion(tee, resp, TEE_DEFAULT_TIMEOUT); + if (ret) + return ret; + + memcpy(buf, &resp->buf[0], len); + *status = resp->status; + + return 0; +} +EXPORT_SYMBOL(psp_tee_process_cmd); diff --git a/drivers/crypto/ccp/tee-dev.h b/drivers/crypto/ccp/tee-dev.h index b3db0fcb550c..f09960112115 100644 --- a/drivers/crypto/ccp/tee-dev.h +++ b/drivers/crypto/ccp/tee-dev.h @@ -54,6 +54,7 @@ struct tee_init_ring_cmd { * @wptr: index to the last written entry in ring buffer */ struct ring_buf_manager { + struct mutex mutex; /* synchronizes access to ring buffer */ void *ring_start; u32 ring_size; phys_addr_t ring_pa; diff --git a/include/linux/psp-tee.h b/include/linux/psp-tee.h new file mode 100644 index 000000000000..63bb2212fce0 --- /dev/null +++ b/include/linux/psp-tee.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: MIT */ +/* + * AMD Trusted Execution Environment (TEE) interface + * + * Author: Rijo Thomas + * + * Copyright 2019 Advanced Micro Devices, Inc. + * + */ + +#ifndef __PSP_TEE_H_ +#define __PSP_TEE_H_ + +#include +#include + +/* This file defines the Trusted Execution Environment (TEE) interface commands + * and the API exported by AMD Secure Processor driver to communicate with + * AMD-TEE Trusted OS. + */ + +/** + * enum tee_cmd_id - TEE Interface Command IDs + * @TEE_CMD_ID_LOAD_TA: Load Trusted Application (TA) binary into + * TEE environment + * @TEE_CMD_ID_UNLOAD_TA: Unload TA binary from TEE environment + * @TEE_CMD_ID_OPEN_SESSION: Open session with loaded TA + * @TEE_CMD_ID_CLOSE_SESSION: Close session with loaded TA + * @TEE_CMD_ID_INVOKE_CMD: Invoke a command with loaded TA + * @TEE_CMD_ID_MAP_SHARED_MEM: Map shared memory + * @TEE_CMD_ID_UNMAP_SHARED_MEM: Unmap shared memory + */ +enum tee_cmd_id { + TEE_CMD_ID_LOAD_TA = 1, + TEE_CMD_ID_UNLOAD_TA, + TEE_CMD_ID_OPEN_SESSION, + TEE_CMD_ID_CLOSE_SESSION, + TEE_CMD_ID_INVOKE_CMD, + TEE_CMD_ID_MAP_SHARED_MEM, + TEE_CMD_ID_UNMAP_SHARED_MEM, +}; + +#ifdef CONFIG_CRYPTO_DEV_SP_PSP +/** + * psp_tee_process_cmd() - Process command in Trusted Execution Environment + * @cmd_id: TEE command ID (&enum tee_cmd_id) + * @buf: Command buffer for TEE processing. On success, is updated + * with the response + * @len: Length of command buffer in bytes + * @status: On success, holds the TEE command execution status + * + * This function submits a command to the Trusted OS for processing in the + * TEE environment and waits for a response or until the command times out. + * + * Returns: + * 0 if TEE successfully processed the command + * -%ENODEV if PSP device not available + * -%EINVAL if invalid input + * -%ETIMEDOUT if TEE command timed out + * -%EBUSY if PSP device is not responsive + */ +int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len, + u32 *status); + +#else /* !CONFIG_CRYPTO_DEV_SP_PSP */ + +static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, + size_t len, u32 *status) +{ + return -ENODEV; +} +#endif /* CONFIG_CRYPTO_DEV_SP_PSP */ +#endif /* __PSP_TEE_H_ */ -- cgit v1.2.3-70-g09d2 From bade7e1fbd34f46462e6eb1db5474832a4144ac2 Mon Sep 17 00:00:00 2001 From: Rijo Thomas Date: Fri, 27 Dec 2019 10:54:02 +0530 Subject: tee: amdtee: check TEE status during driver initialization The AMD-TEE driver should check if TEE is available before registering itself with TEE subsystem. This ensures that there is a TEE which the driver can talk to before proceeding with tee device node allocation. Cc: Ard Biesheuvel Cc: Tom Lendacky Acked-by: Jens Wiklander Co-developed-by: Devaraj Rangasamy Signed-off-by: Devaraj Rangasamy Signed-off-by: Rijo Thomas Reviewed-by: Gary R Hook Signed-off-by: Herbert Xu --- drivers/crypto/ccp/tee-dev.c | 11 +++++++++++ drivers/tee/amdtee/core.c | 6 ++++++ include/linux/psp-tee.h | 18 ++++++++++++++++++ 3 files changed, 35 insertions(+) (limited to 'drivers/crypto/ccp/tee-dev.c') diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c index 555c8a7c5684..5e697a90ea7f 100644 --- a/drivers/crypto/ccp/tee-dev.c +++ b/drivers/crypto/ccp/tee-dev.c @@ -362,3 +362,14 @@ int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len, return 0; } EXPORT_SYMBOL(psp_tee_process_cmd); + +int psp_check_tee_status(void) +{ + struct psp_device *psp = psp_get_master_device(); + + if (!psp || !psp->tee_data) + return -ENODEV; + + return 0; +} +EXPORT_SYMBOL(psp_check_tee_status); diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c index dd360f378ef0..9d0cee1c837f 100644 --- a/drivers/tee/amdtee/core.c +++ b/drivers/tee/amdtee/core.c @@ -16,6 +16,7 @@ #include #include "amdtee_private.h" #include "../tee_private.h" +#include static struct amdtee_driver_data *drv_data; static DEFINE_MUTEX(session_list_mutex); @@ -438,6 +439,10 @@ static int __init amdtee_driver_init(void) struct tee_shm_pool *pool = ERR_PTR(-EINVAL); int rc; + rc = psp_check_tee_status(); + if (rc) + goto err_fail; + drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL); if (IS_ERR(drv_data)) return -ENOMEM; @@ -485,6 +490,7 @@ err_kfree_drv_data: kfree(drv_data); drv_data = NULL; +err_fail: pr_err("amd-tee driver initialization failed\n"); return rc; } diff --git a/include/linux/psp-tee.h b/include/linux/psp-tee.h index 63bb2212fce0..cb0c95d6d76b 100644 --- a/include/linux/psp-tee.h +++ b/include/linux/psp-tee.h @@ -62,6 +62,19 @@ enum tee_cmd_id { int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len, u32 *status); +/** + * psp_check_tee_status() - Checks whether there is a TEE which a driver can + * talk to. + * + * This function can be used by AMD-TEE driver to query if there is TEE with + * which it can communicate. + * + * Returns: + * 0 if the device has TEE + * -%ENODEV if there is no TEE available + */ +int psp_check_tee_status(void); + #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, @@ -69,5 +82,10 @@ static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, { return -ENODEV; } + +static inline int psp_check_tee_status(void) +{ + return -ENODEV; +} #endif /* CONFIG_CRYPTO_DEV_SP_PSP */ #endif /* __PSP_TEE_H_ */ -- cgit v1.2.3-70-g09d2