[PATCH 6.6 186/283] crypto: ccp - Move direct access to some PSP registers out of TEE

Sasha Levin
2026-02-28T18:09:45Z

From: Tom Lendacky <thomas.lendacky@amd.com>

[ Upstream commit 949a0c8dd3c257730ef7205be759e4bc6cf49cea ]

With the PSP mailbox registers supporting more than just TEE, access to
them must be maintained and serialized by the PSP device support. Remove
TEE support direct access and create an interface in the PSP support
where the register access can be controlled/serialized.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Tested-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: 7b85137caf11 ("crypto: ccp - Send PSP_CMD_TEE_RING_DESTROY when PSP_CMD_TEE_RING_INIT fails")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/crypto/ccp/psp-dev.c | 60 ++++++++++++++++++++++++++++++++++++
drivers/crypto/ccp/psp-dev.h | 18 +++++++++++
drivers/crypto/ccp/sp-dev.h | 3 ++
drivers/crypto/ccp/sp-pci.c | 18 +++++++----
drivers/crypto/ccp/tee-dev.c | 48 ++++++-----------------------
drivers/crypto/ccp/tee-dev.h | 15 ++-------
6 files changed, 104 insertions(+), 58 deletions(-)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index d001abc350cd2..5f591bce09521 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -9,6 +9,9 @@

#include <linux/kernel.h>
#include <linux/irqreturn.h>
+#include <linux/mutex.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>

#include "sp-dev.h"
#include "psp-dev.h"
@@ -19,6 +22,62 @@

struct psp_device *psp_master;

+#define PSP_C2PMSG_17_CMDRESP_CMD GENMASK(19, 16)
+
+static int psp_mailbox_poll(const void __iomem *cmdresp_reg, unsigned int *cmdresp,
+ unsigned int timeout_msecs)
+{
+ while (true) {
+ *cmdresp = ioread32(cmdresp_reg);
+ if (FIELD_GET(PSP_CMDRESP_RESP, *cmdresp))
+ return 0;
+
+ if (!timeout_msecs--)
+ break;
+
+ usleep_range(1000, 1100);
+ }
+
+ return -ETIMEDOUT;
+}
+
+int psp_mailbox_command(struct psp_device *psp, enum psp_cmd cmd, void *cmdbuff,
+ unsigned int timeout_msecs, unsigned int *cmdresp)
+{
+ void __iomem *cmdresp_reg, *cmdbuff_lo_reg, *cmdbuff_hi_reg;
+ int ret;
+
+ if (!psp || !psp->vdata || !psp->vdata->cmdresp_reg ||
+ !psp->vdata->cmdbuff_addr_lo_reg || !psp->vdata->cmdbuff_addr_hi_reg)
+ return -ENODEV;
+
+ cmdresp_reg = psp->io_regs + psp->vdata->cmdresp_reg;
+ cmdbuff_lo_reg = psp->io_regs + psp->vdata->cmdbuff_addr_lo_reg;
+ cmdbuff_hi_reg = psp->io_regs + psp->vdata->cmdbuff_addr_hi_reg;
+
+ mutex_lock(&psp->mailbox_mutex);
+
+ /* Ensure mailbox is ready for a command */
+ ret = -EBUSY;
+ if (psp_mailbox_poll(cmdresp_reg, cmdresp, 0))
+ goto unlock;
+
+ if (cmdbuff) {
+ iowrite32(lower_32_bits(__psp_pa(cmdbuff)), cmdbuff_lo_reg);
+ iowrite32(upper_32_bits(__psp_pa(cmdbuff)), cmdbuff_hi_reg);
+ }
+
+ *cmdresp = FIELD_PREP(PSP_C2PMSG_17_CMDRESP_CMD, cmd);
+ iowrite32(*cmdresp, cmdresp_reg);
+
+ ret = psp_mailbox_poll(cmdresp_reg, cmdresp, timeout_msecs);
+
+unlock:
+ mutex_unlock(&psp->mailbox_mutex);
+
+ return ret;
+}
+
static struct psp_device *psp_alloc_struct(struct sp_device *sp)
{
struct device *dev = sp->dev;
@@ -164,6 +223,7 @@ int psp_dev_init(struct sp_device *sp)
}

psp->io_regs = sp->io_map;
+ mutex_init(&psp->mailbox_mutex);

ret = psp_get_capability(psp);
if (ret)
diff --git a/drivers/crypto/ccp/psp-dev.h b/drivers/crypto/ccp/psp-dev.h
index 8a4de69399c59..d917657c6085a 100644
--- a/drivers/crypto/ccp/psp-dev.h
+++ b/drivers/crypto/ccp/psp-dev.h
@@ -14,6 +14,8 @@
#include <linux/list.h>
#include <linux/bits.h>
#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/psp.h>

#include "sp-dev.h"

@@ -33,6 +35,7 @@ struct psp_device {
struct sp_device *sp;

void __iomem *io_regs;
+ struct mutex mailbox_mutex;

psp_irq_handler_t sev_irq_handler;
void *sev_irq_data;
@@ -71,4 +74,19 @@ struct psp_device *psp_get_master_device(void);
#define PSP_SECURITY_HSP_TPM_AVAILABLE BIT(10)
#define PSP_SECURITY_ROM_ARMOR_ENFORCED BIT(11)

+/**
+ * enum psp_cmd - PSP mailbox commands
+ * @PSP_CMD_TEE_RING_INIT: Initialize TEE ring buffer
+ * @PSP_CMD_TEE_RING_DESTROY: Destroy TEE ring buffer
+ * @PSP_CMD_MAX: Maximum command id
+ */
+enum psp_cmd {
+ PSP_CMD_TEE_RING_INIT = 1,
+ PSP_CMD_TEE_RING_DESTROY = 2,
+ PSP_CMD_MAX = 15,
+};
+
+int psp_mailbox_command(struct psp_device *psp, enum psp_cmd cmd, void *cmdbuff,
+ unsigned int timeout_msecs, unsigned int *cmdresp);
+
#endif /* __PSP_DEV_H */
diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
index 8bbef2426acd4..2efe4a6ef544f 100644
--- a/drivers/crypto/ccp/sp-dev.h
+++ b/drivers/crypto/ccp/sp-dev.h
@@ -71,6 +71,9 @@ struct psp_vdata {
const struct sev_vdata *sev;
const struct tee_vdata *tee;
const struct platform_access_vdata *platform_access;
+ const unsigned int cmdresp_reg;
+ const unsigned int cmdbuff_addr_lo_reg;
+ const unsigned int cmdbuff_addr_hi_reg;
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 8f1b032f7e633..86517bb4c1952 100644
--- a/drivers/crypto/ccp/sp-pci.c
+++ b/drivers/crypto/ccp/sp-pci.c
@@ -428,18 +428,12 @@ static const struct sev_vdata sevv2 = {
};

static const struct tee_vdata teev1 = {
- .cmdresp_reg = 0x10544, /* C2PMSG_17 */
- .cmdbuff_addr_lo_reg = 0x10548, /* C2PMSG_18 */
- .cmdbuff_addr_hi_reg = 0x1054c, /* C2PMSG_19 */
.ring_wptr_reg = 0x10550, /* C2PMSG_20 */
.ring_rptr_reg = 0x10554, /* C2PMSG_21 */
.info_reg = 0x109e8, /* C2PMSG_58 */
};

static const struct tee_vdata teev2 = {
- .cmdresp_reg = 0x10944, /* C2PMSG_17 */
- .cmdbuff_addr_lo_reg = 0x10948, /* C2PMSG_18 */
- .cmdbuff_addr_hi_reg = 0x1094c, /* C2PMSG_19 */
.ring_wptr_reg = 0x10950, /* C2PMSG_20 */
.ring_rptr_reg = 0x10954, /* C2PMSG_21 */
};
@@ -476,6 +470,9 @@ static const struct psp_vdata pspv2 = {
static const struct psp_vdata pspv3 = {
.tee = &teev1,
.platform_access = &pa_v1,
+ .cmdresp_reg = 0x10544, /* C2PMSG_17 */
+ .cmdbuff_addr_lo_reg = 0x10548, /* C2PMSG_18 */
+ .cmdbuff_addr_hi_reg = 0x1054c, /* C2PMSG_19 */
.bootloader_info_reg = 0x109ec, /* C2PMSG_59 */
.feature_reg = 0x109fc, /* C2PMSG_63 */
.inten_reg = 0x10690, /* P2CMSG_INTEN */
@@ -486,6 +483,9 @@ static const struct psp_vdata pspv3 = {
static const struct psp_vdata pspv4 = {
.sev = &sevv2,
.tee = &teev1,
+ .cmdresp_reg = 0x10544, /* C2PMSG_17 */
+ .cmdbuff_addr_lo_reg = 0x10548, /* C2PMSG_18 */
+ .cmdbuff_addr_hi_reg = 0x1054c, /* C2PMSG_19 */
.bootloader_info_reg = 0x109ec, /* C2PMSG_59 */
.feature_reg = 0x109fc, /* C2PMSG_63 */
.inten_reg = 0x10690, /* P2CMSG_INTEN */
@@ -495,6 +495,9 @@ static const struct psp_vdata pspv4 = {
static const struct psp_vdata pspv5 = {
.tee = &teev2,
.platform_access = &pa_v2,
+ .cmdresp_reg = 0x10944, /* C2PMSG_17 */
+ .cmdbuff_addr_lo_reg = 0x10948, /* C2PMSG_18 */
+ .cmdbuff_addr_hi_reg = 0x1094c, /* C2PMSG_19 */
.feature_reg = 0x109fc, /* C2PMSG_63 */
.inten_reg = 0x10510, /* P2CMSG_INTEN */
.intsts_reg = 0x10514, /* P2CMSG_INTSTS */
@@ -503,6 +506,9 @@ static const struct psp_vdata pspv5 = {
static const struct psp_vdata pspv6 = {
.sev = &sevv2,
.tee = &teev2,
+ .cmdresp_reg = 0x10944, /* C2PMSG_17 */
+ .cmdbuff_addr_lo_reg = 0x10948, /* C2PMSG_18 */
+ .cmdbuff_addr_hi_reg = 0x1094c, /* C2PMSG_19 */
.feature_reg = 0x109fc, /* C2PMSG_63 */
.inten_reg = 0x10510, /* P2CMSG_INTEN */
.intsts_reg = 0x10514, /* P2CMSG_INTSTS */
diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c
index 9c02706e94948..0ccd0e29b0380 100644
--- a/drivers/crypto/ccp/tee-dev.c
+++ b/drivers/crypto/ccp/tee-dev.c
@@ -62,26 +62,6 @@ static void tee_free_ring(struct psp_tee_device *tee)
mutex_destroy(&rb_mgr->mutex);
}

-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 (FIELD_GET(PSP_CMDRESP_RESP, *reg))
- 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)
{
@@ -110,7 +90,6 @@ 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;

@@ -130,23 +109,15 @@ static int tee_init_ring(struct psp_tee_device *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);
+ ret = psp_mailbox_command(tee->psp, PSP_CMD_TEE_RING_INIT, cmd,
+ TEE_DEFAULT_CMD_TIMEOUT, &reg);
if (ret) {
- dev_err(tee->dev, "tee: ring init command timed out\n");
+ dev_err(tee->dev, "tee: ring init command timed out, disabling TEE support\n");
tee_free_ring(tee);
+ psp_dead = true;
goto free_buf;
}

@@ -174,12 +145,11 @@ static void tee_destroy_ring(struct psp_tee_device *tee)
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);
+ ret = psp_mailbox_command(tee->psp, PSP_CMD_TEE_RING_DESTROY, NULL,
+ TEE_DEFAULT_CMD_TIMEOUT, &reg);
if (ret) {
- dev_err(tee->dev, "tee: ring destroy command timed out\n");
+ dev_err(tee->dev, "tee: ring destroy command timed out, disabling TEE support\n");
+ psp_dead = true;
} else if (FIELD_GET(PSP_CMDRESP_STS, reg)) {
dev_err(tee->dev, "tee: ring destroy command failed (%#010lx)\n",
FIELD_GET(PSP_CMDRESP_STS, reg));
@@ -370,7 +340,7 @@ int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len,
if (ret)
return ret;

- ret = tee_wait_cmd_completion(tee, resp, TEE_DEFAULT_TIMEOUT);
+ ret = tee_wait_cmd_completion(tee, resp, TEE_DEFAULT_RING_TIMEOUT);
if (ret) {
resp->flag = CMD_RESPONSE_TIMEDOUT;
return ret;
diff --git a/drivers/crypto/ccp/tee-dev.h b/drivers/crypto/ccp/tee-dev.h
index b0bf1de94ea6f..c23416cb7bb37 100644
--- a/drivers/crypto/ccp/tee-dev.h
+++ b/drivers/crypto/ccp/tee-dev.h
@@ -17,21 +17,10 @@
#include <linux/device.h>
#include <linux/mutex.h>

-#define TEE_DEFAULT_TIMEOUT 10
+#define TEE_DEFAULT_CMD_TIMEOUT (10 * MSEC_PER_SEC)
+#define TEE_DEFAULT_RING_TIMEOUT 10
#define MAX_BUFFER_SIZE 988

-/**
- * 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
--
2.51.0