[RFC PATCH 4/5] crypto: ccp - add TEE support for Raven Ridge

From: Thomas, Rijo-john
Date: Wed Oct 23 2019 - 07:27:47 EST

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.

Signed-off-by: Rijo Thomas <Rijo-john.Thomas@xxxxxxx>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@xxxxxxx>
---
drivers/crypto/ccp/Makefile | 3 +-
drivers/crypto/ccp/psp-dev.c | 74 +++++++++++++-
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 | 237 +++++++++++++++++++++++++++++++++++++++++++
drivers/crypto/ccp/tee-dev.h | 108 ++++++++++++++++++++
7 files changed, 461 insertions(+), 7 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 ef8affa..90bcd5f 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. */
@@ -53,10 +57,11 @@ static irqreturn_t psp_irq_handler(int irq, void *data)
return IRQ_HANDLED;
}

-static int psp_check_sev_support(struct psp_device *psp)
+static int psp_check_sev_support(struct psp_device *psp,
+ unsigned int capability)
{
/* Check if device supports SEV feature */
- if (!(ioread32(psp->io_regs + psp->vdata->feature_reg) & 1)) {
+ if (!(capability & 1)) {
dev_dbg(psp->dev, "psp does not support SEV\n");
return -ENODEV;
}
@@ -64,10 +69,54 @@ static int psp_check_sev_support(struct psp_device *psp)
return 0;
}

+static int psp_check_tee_support(struct psp_device *psp,
+ unsigned int capability)
+{
+ /* Check if device supports TEE feature */
+ if (!(capability & 2)) {
+ dev_dbg(psp->dev, "psp does not support TEE\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int psp_check_support(struct psp_device *psp, unsigned int capability)
+{
+ int sev_support = psp_check_sev_support(psp, capability);
+ int tee_support = psp_check_tee_support(psp, capability);
+
+ /* Check if device supprts SEV and TEE feature */
+ if (sev_support && tee_support)
+ return -ENODEV;
+
+ 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;
struct psp_device *psp;
+ unsigned int capability;
int ret;

ret = -ENOMEM;
@@ -86,7 +135,10 @@ int psp_dev_init(struct sp_device *sp)

psp->io_regs = sp->io_map;

- ret = psp_check_sev_support(psp);
+ /* Read the feature register to get the PSP capability */
+ capability = ioread32(psp->io_regs + psp->vdata->feature_reg);
+
+ ret = psp_check_support(psp, capability);
if (ret)
goto e_disable;

@@ -101,7 +153,7 @@ 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;

@@ -139,6 +191,8 @@ void psp_dev_destroy(struct sp_device *sp)

sev_dev_destroy(psp);

+ tee_dev_destroy(psp);
+
sp_free_psp_irq(sp, psp);
}

@@ -154,6 +208,18 @@ 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@xxxxxxx>
* Author: Gary R Hook <gary.hook@xxxxxxx>
@@ -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@xxxxxxx>
* Author: Gary R Hook <gary.hook@xxxxxxx>
@@ -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..b2b0215
--- /dev/null
+++ b/drivers/crypto/ccp/tee-dev.c
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: MIT
+/*
+ * AMD Trusted Execution Environment (TEE) interface
+ *
+ * Author: Rijo Thomas <Rijo-john.Thomas@xxxxxxx>
+ *
+ * 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..0d51a0a7
--- /dev/null
+++ b/drivers/crypto/ccp/tee-dev.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ *
+ * Author: Rijo Thomas <Rijo-john.Thomas@xxxxxxx>
+ *
+ */
+
+/* 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__ */
--
1.9.1