Re: [PATCH 1/5] crypto: ccp: Move direct access to some PSP registers out of TEE

Rijo Thomas
2023-09-14T07:19:19Z

On 9/8/2023 12:18 AM, Mario Limonciello wrote:
> From: Tom Lendacky <thomas.lendacky@amd.com>
>
> 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.
>

Reviewed-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Tested-by: Rijo Thomas <Rijo-john.Thomas@amd.com>

> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> 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 d42d7bc62352..3258c4612e14 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 8a4de69399c5..d917657c6085 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 2329ad524b49..c4e125efe6c7 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 b6ab56abeb68..d1aedc5c1a68 100644
> --- a/drivers/crypto/ccp/sp-pci.c
> +++ b/drivers/crypto/ccp/sp-pci.c
> @@ -418,18 +418,12 @@ 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 */
> };
> @@ -466,6 +460,9 @@ 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 */
> @@ -476,6 +473,9 @@ 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 */
> @@ -485,6 +485,9 @@ 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 */
> @@ -493,6 +496,9 @@ 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 5560bf8329a1..5e1d80724678 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 49d26158b71e..ea9a2b7c05f5 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