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authorRijo Thomas <Rijo-john.Thomas@amd.com>2019-12-04 11:49:02 +0530
committerHerbert Xu <herbert@gondor.apana.org.au>2019-12-20 14:58:32 +0800
commit33960acccfbd7f24d443cb3d0312ac28abe62bae (patch)
tree03a0393859b080181a2d233845e56798c0fc76b9 /drivers/crypto/ccp/tee-dev.c
parentf100ab62b68922c343a8efc84e83d2275c1ade47 (diff)
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 <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> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/ccp/tee-dev.c')
-rw-r--r--drivers/crypto/ccp/tee-dev.c238
1 files changed, 238 insertions, 0 deletions
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 <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);
+}