Re: [RFC PATCH v3 5/6] crypto: ccp - add TEE support for Raven Ridge

[Gary R Hook <gary.hook@amd.com>]

On 12/4/19 12:19 AM, Rijo Thomas wrote:
> 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 <jens.wiklander@linaro.org>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
> Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
> Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>

Acked-by: Gary R Hook <gary.hook@amd.com>

> ---
>   drivers/crypto/ccp/Makefile  |   3 +-
>   drivers/crypto/ccp/psp-dev.c |  39 ++++++-
>   drivers/crypto/ccp/psp-dev.h |   8 ++
>   drivers/crypto/ccp/sp-dev.h  |  11 +-
>   drivers/crypto/ccp/sp-pci.c  |  27 ++++-
>   drivers/crypto/ccp/tee-dev.c | 238 +++++++++++++++++++++++++++++++++++++++++++
>   drivers/crypto/ccp/tee-dev.h | 109 ++++++++++++++++++++
>   7 files changed, 431 insertions(+), 4 deletions(-)
>   create mode 100644 drivers/crypto/ccp/tee-dev.c
>   create mode 100644 drivers/crypto/ccp/tee-dev.h
> 
> diff --git a/drivers/crypto/ccp/Makefile b/drivers/crypto/ccp/Makefile
> index 3b29ea4..db362fe 100644
> --- a/drivers/crypto/ccp/Makefile
> +++ b/drivers/crypto/ccp/Makefile
> @@ -9,7 +9,8 @@ ccp-$(CONFIG_CRYPTO_DEV_SP_CCP) += ccp-dev.o \
>   ccp-$(CONFIG_CRYPTO_DEV_CCP_DEBUGFS) += ccp-debugfs.o
>   ccp-$(CONFIG_PCI) += sp-pci.o
>   ccp-$(CONFIG_CRYPTO_DEV_SP_PSP) += psp-dev.o \
> -                                   sev-dev.o
> +                                   sev-dev.o \
> +                                   tee-dev.o
>   
>   obj-$(CONFIG_CRYPTO_DEV_CCP_CRYPTO) += ccp-crypto.o
>   ccp-crypto-objs := ccp-crypto-main.o \
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 3bedf72..e95e7aa 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -13,6 +13,7 @@
>   #include "sp-dev.h"
>   #include "psp-dev.h"
>   #include "sev-dev.h"
> +#include "tee-dev.h"
>   
>   struct psp_device *psp_master;
>   
> @@ -45,6 +46,9 @@ static irqreturn_t psp_irq_handler(int irq, void *data)
>   	if (status) {
>   		if (psp->sev_irq_handler)
>   			psp->sev_irq_handler(irq, psp->sev_irq_data, status);
> +
> +		if (psp->tee_irq_handler)
> +			psp->tee_irq_handler(irq, psp->tee_irq_data, status);
>   	}
>   
>   	/* Clear the interrupt status by writing the same value we read. */
> @@ -109,6 +113,25 @@ static int psp_check_support(struct psp_device *psp,
>   	return 0;
>   }
>   
> +static int psp_init(struct psp_device *psp, unsigned int capability)
> +{
> +	int ret;
> +
> +	if (!psp_check_sev_support(psp, capability)) {
> +		ret = sev_dev_init(psp);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (!psp_check_tee_support(psp, capability)) {
> +		ret = tee_dev_init(psp);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   int psp_dev_init(struct sp_device *sp)
>   {
>   	struct device *dev = sp->dev;
> @@ -151,7 +174,7 @@ int psp_dev_init(struct sp_device *sp)
>   		goto e_err;
>   	}
>   
> -	ret = sev_dev_init(psp);
> +	ret = psp_init(psp, capability);
>   	if (ret)
>   		goto e_irq;
>   
> @@ -189,6 +212,8 @@ void psp_dev_destroy(struct sp_device *sp)
>   
>   	sev_dev_destroy(psp);
>   
> +	tee_dev_destroy(psp);
> +
>   	sp_free_psp_irq(sp, psp);
>   }
>   
> @@ -204,6 +229,18 @@ void psp_clear_sev_irq_handler(struct psp_device *psp)
>   	psp_set_sev_irq_handler(psp, NULL, NULL);
>   }
>   
> +void psp_set_tee_irq_handler(struct psp_device *psp, psp_irq_handler_t handler,
> +			     void *data)
> +{
> +	psp->tee_irq_data = data;
> +	psp->tee_irq_handler = handler;
> +}
> +
> +void psp_clear_tee_irq_handler(struct psp_device *psp)
> +{
> +	psp_set_tee_irq_handler(psp, NULL, NULL);
> +}
> +
>   struct psp_device *psp_get_master_device(void)
>   {
>   	struct sp_device *sp = sp_get_psp_master_device();
> diff --git a/drivers/crypto/ccp/psp-dev.h b/drivers/crypto/ccp/psp-dev.h
> index 7c014ac..ef38e41 100644
> --- a/drivers/crypto/ccp/psp-dev.h
> +++ b/drivers/crypto/ccp/psp-dev.h
> @@ -40,13 +40,21 @@ struct psp_device {
>   	psp_irq_handler_t sev_irq_handler;
>   	void *sev_irq_data;
>   
> +	psp_irq_handler_t tee_irq_handler;
> +	void *tee_irq_data;
> +
>   	void *sev_data;
> +	void *tee_data;
>   };
>   
>   void psp_set_sev_irq_handler(struct psp_device *psp, psp_irq_handler_t handler,
>   			     void *data);
>   void psp_clear_sev_irq_handler(struct psp_device *psp);
>   
> +void psp_set_tee_irq_handler(struct psp_device *psp, psp_irq_handler_t handler,
> +			     void *data);
> +void psp_clear_tee_irq_handler(struct psp_device *psp);
> +
>   struct psp_device *psp_get_master_device(void);
>   
>   #endif /* __PSP_DEV_H */
> diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
> index 0394c75..4235946 100644
> --- a/drivers/crypto/ccp/sp-dev.h
> +++ b/drivers/crypto/ccp/sp-dev.h
> @@ -2,7 +2,7 @@
>   /*
>    * AMD Secure Processor driver
>    *
> - * Copyright (C) 2017-2018 Advanced Micro Devices, Inc.
> + * Copyright (C) 2017-2019 Advanced Micro Devices, Inc.
>    *
>    * Author: Tom Lendacky <thomas.lendacky@amd.com>
>    * Author: Gary R Hook <gary.hook@amd.com>
> @@ -45,8 +45,17 @@ struct sev_vdata {
>   	const unsigned int cmdbuff_addr_hi_reg;
>   };
>   
> +struct tee_vdata {
> +	const unsigned int cmdresp_reg;
> +	const unsigned int cmdbuff_addr_lo_reg;
> +	const unsigned int cmdbuff_addr_hi_reg;
> +	const unsigned int ring_wptr_reg;
> +	const unsigned int ring_rptr_reg;
> +};
> +
>   struct psp_vdata {
>   	const struct sev_vdata *sev;
> +	const struct tee_vdata *tee;
>   	const unsigned int feature_reg;
>   	const unsigned int inten_reg;
>   	const unsigned int intsts_reg;
> diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
> index 733693d..56c1f61 100644
> --- a/drivers/crypto/ccp/sp-pci.c
> +++ b/drivers/crypto/ccp/sp-pci.c
> @@ -2,7 +2,7 @@
>   /*
>    * AMD Secure Processor device driver
>    *
> - * Copyright (C) 2013,2018 Advanced Micro Devices, Inc.
> + * Copyright (C) 2013,2019 Advanced Micro Devices, Inc.
>    *
>    * Author: Tom Lendacky <thomas.lendacky@amd.com>
>    * Author: Gary R Hook <gary.hook@amd.com>
> @@ -274,6 +274,14 @@ static int sp_pci_resume(struct pci_dev *pdev)
>   	.cmdbuff_addr_hi_reg	= 0x109e4,
>   };
>   
> +static const struct tee_vdata teev1 = {
> +	.cmdresp_reg		= 0x10544,
> +	.cmdbuff_addr_lo_reg	= 0x10548,
> +	.cmdbuff_addr_hi_reg	= 0x1054c,
> +	.ring_wptr_reg          = 0x10550,
> +	.ring_rptr_reg          = 0x10554,
> +};
> +
>   static const struct psp_vdata pspv1 = {
>   	.sev			= &sevv1,
>   	.feature_reg		= 0x105fc,
> @@ -287,6 +295,13 @@ static int sp_pci_resume(struct pci_dev *pdev)
>   	.inten_reg		= 0x10690,
>   	.intsts_reg		= 0x10694,
>   };
> +
> +static const struct psp_vdata pspv3 = {
> +	.tee			= &teev1,
> +	.feature_reg		= 0x109fc,
> +	.inten_reg		= 0x10690,
> +	.intsts_reg		= 0x10694,
> +};
>   #endif
>   
>   static const struct sp_dev_vdata dev_vdata[] = {
> @@ -320,12 +335,22 @@ static int sp_pci_resume(struct pci_dev *pdev)
>   		.psp_vdata = &pspv2,
>   #endif
>   	},
> +	{	/* 4 */
> +		.bar = 2,
> +#ifdef CONFIG_CRYPTO_DEV_SP_CCP
> +		.ccp_vdata = &ccpv5a,
> +#endif
> +#ifdef CONFIG_CRYPTO_DEV_SP_PSP
> +		.psp_vdata = &pspv3,
> +#endif
> +	},
>   };
>   static const struct pci_device_id sp_pci_table[] = {
>   	{ PCI_VDEVICE(AMD, 0x1537), (kernel_ulong_t)&dev_vdata[0] },
>   	{ PCI_VDEVICE(AMD, 0x1456), (kernel_ulong_t)&dev_vdata[1] },
>   	{ PCI_VDEVICE(AMD, 0x1468), (kernel_ulong_t)&dev_vdata[2] },
>   	{ PCI_VDEVICE(AMD, 0x1486), (kernel_ulong_t)&dev_vdata[3] },
> +	{ PCI_VDEVICE(AMD, 0x15DF), (kernel_ulong_t)&dev_vdata[4] },
>   	/* Last entry must be zero */
>   	{ 0, }
>   };
> diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c
> new file mode 100644
> index 0000000..ccbc2ce
> --- /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 <Rijo-john.Thomas@amd.com>
> + * Author: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
> + *
> + * Copyright 2019 Advanced Micro Devices, Inc.
> + */
> +
> +#include <linux/types.h>
> +#include <linux/mutex.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/gfp.h>
> +#include <linux/psp-sev.h>
> +
> +#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, &reg);
> +	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, &reg);
> +	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);
> +}
> diff --git a/drivers/crypto/ccp/tee-dev.h b/drivers/crypto/ccp/tee-dev.h
> new file mode 100644
> index 0000000..b3db0fc
> --- /dev/null
> +++ b/drivers/crypto/ccp/tee-dev.h
> @@ -0,0 +1,109 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright 2019 Advanced Micro Devices, Inc.
> + *
> + * Author: Rijo Thomas <Rijo-john.Thomas@amd.com>
> + * Author: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
> + *
> + */
> +
> +/* This file describes the TEE communication interface between host and AMD
> + * Secure Processor
> + */
> +
> +#ifndef __TEE_DEV_H__
> +#define __TEE_DEV_H__
> +
> +#include <linux/device.h>
> +#include <linux/mutex.h>
> +
> +#define TEE_DEFAULT_TIMEOUT		10
> +#define MAX_BUFFER_SIZE			992
> +
> +/**
> + * enum tee_ring_cmd_id - TEE interface commands for ring buffer configuration
> + * @TEE_RING_INIT_CMD:		Initialize ring buffer
> + * @TEE_RING_DESTROY_CMD:	Destroy ring buffer
> + * @TEE_RING_MAX_CMD:		Maximum command id
> + */
> +enum tee_ring_cmd_id {
> +	TEE_RING_INIT_CMD		= 0x00010000,
> +	TEE_RING_DESTROY_CMD		= 0x00020000,
> +	TEE_RING_MAX_CMD		= 0x000F0000,
> +};
> +
> +/**
> + * struct tee_init_ring_cmd - Command to init TEE ring buffer
> + * @low_addr:  bits [31:0] of the physical address of ring buffer
> + * @hi_addr:   bits [63:32] of the physical address of ring buffer
> + * @size:      size of ring buffer in bytes
> + */
> +struct tee_init_ring_cmd {
> +	u32 low_addr;
> +	u32 hi_addr;
> +	u32 size;
> +};
> +
> +#define MAX_RING_BUFFER_ENTRIES		32
> +
> +/**
> + * struct ring_buf_manager - Helper structure to manage ring buffer.
> + * @ring_start:  starting address of ring buffer
> + * @ring_size:   size of ring buffer in bytes
> + * @ring_pa:     physical address of ring buffer
> + * @wptr:        index to the last written entry in ring buffer
> + */
> +struct ring_buf_manager {
> +	void *ring_start;
> +	u32 ring_size;
> +	phys_addr_t ring_pa;
> +	u32 wptr;
> +};
> +
> +struct psp_tee_device {
> +	struct device *dev;
> +	struct psp_device *psp;
> +	void __iomem *io_regs;
> +	struct tee_vdata *vdata;
> +	struct ring_buf_manager rb_mgr;
> +};
> +
> +/**
> + * enum tee_cmd_state - TEE command states for the ring buffer interface
> + * @TEE_CMD_STATE_INIT:      initial state of command when sent from host
> + * @TEE_CMD_STATE_PROCESS:   command being processed by TEE environment
> + * @TEE_CMD_STATE_COMPLETED: command processing completed
> + */
> +enum tee_cmd_state {
> +	TEE_CMD_STATE_INIT,
> +	TEE_CMD_STATE_PROCESS,
> +	TEE_CMD_STATE_COMPLETED,
> +};
> +
> +/**
> + * struct tee_ring_cmd - Structure of the command buffer in TEE ring
> + * @cmd_id:      refers to &enum tee_cmd_id. Command id for the ring buffer
> + *               interface
> + * @cmd_state:   refers to &enum tee_cmd_state
> + * @status:      status of TEE command execution
> + * @res0:        reserved region
> + * @pdata:       private data (currently unused)
> + * @res1:        reserved region
> + * @buf:         TEE command specific buffer
> + */
> +struct tee_ring_cmd {
> +	u32 cmd_id;
> +	u32 cmd_state;
> +	u32 status;
> +	u32 res0[1];
> +	u64 pdata;
> +	u32 res1[2];
> +	u8 buf[MAX_BUFFER_SIZE];
> +
> +	/* Total size: 1024 bytes */
> +} __packed;
> +
> +int tee_dev_init(struct psp_device *psp);
> +void tee_dev_destroy(struct psp_device *psp);
> +
> +#endif /* __TEE_DEV_H__ */
>