On Thu, Jan 18, 2024 at 11:04:33AM +0100, Arnaud Pouliquen wrote:
> The new TEE remoteproc device is used to manage remote firmware in a
> secure, trusted context. The 'st,stm32mp1-m4-tee' compatibility is
> introduced to delegate the loading of the firmware to the trusted
> execution context. In such cases, the firmware should be signed and
> adhere to the image format defined by the TEE.
>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
> ---
> V1 to V2 update:
> - remove the select "TEE_REMOTEPROC" in STM32_RPROC config as detected by
> the kernel test robot:
> WARNING: unmet direct dependencies detected for TEE_REMOTEPROC
> Depends on [n]: REMOTEPROC [=y] && OPTEE [=n]
> Selected by [y]:
> - STM32_RPROC [=y] && (ARCH_STM32 || COMPILE_TEST [=y]) && REMOTEPROC [=y]
> - Fix initialized trproc variable in stm32_rproc_probe
> ---
> drivers/remoteproc/stm32_rproc.c | 149 +++++++++++++++++++++++++++++--
> 1 file changed, 144 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> index fcc0001e2657..cf6a21bac945 100644
> --- a/drivers/remoteproc/stm32_rproc.c
> +++ b/drivers/remoteproc/stm32_rproc.c
> @@ -20,6 +20,7 @@
> #include <linux/remoteproc.h>
> #include <linux/reset.h>
> #include <linux/slab.h>
> +#include <linux/tee_remoteproc.h>
> #include <linux/workqueue.h>
>
> #include "remoteproc_internal.h"
> @@ -49,6 +50,9 @@
> #define M4_STATE_STANDBY 4
> #define M4_STATE_CRASH 5
>
> +/* Remote processor unique identifier aligned with the Trusted Execution Environment definitions */
> +#define STM32_MP1_M4_PROC_ID 0
> +
> struct stm32_syscon {
> struct regmap *map;
> u32 reg;
> @@ -90,6 +94,8 @@ struct stm32_rproc {
> struct stm32_mbox mb[MBOX_NB_MBX];
> struct workqueue_struct *workqueue;
> bool hold_boot_smc;
> + bool fw_loaded;
> + struct tee_rproc *trproc;
> void __iomem *rsc_va;
> };
>
> @@ -257,6 +263,91 @@ static int stm32_rproc_release(struct rproc *rproc)
> return err;
> }
>
> +static int stm32_rproc_tee_elf_sanity_check(struct rproc *rproc,
> + const struct firmware *fw)
> +{
> + struct stm32_rproc *ddata = rproc->priv;
> + unsigned int ret = 0;
> +
> + if (rproc->state == RPROC_DETACHED)
> + return 0;
> +
> + ret = tee_rproc_load_fw(ddata->trproc, fw);
> + if (!ret)
> + ddata->fw_loaded = true;
> +
> + return ret;
> +}
> +
> +static int stm32_rproc_tee_elf_load(struct rproc *rproc,
> + const struct firmware *fw)
> +{
> + struct stm32_rproc *ddata = rproc->priv;
> + unsigned int ret;
> +
> + /*
> + * This function can be called by remote proc for recovery
> + * without the sanity check. In this case we need to load the firmware
> + * else nothing done here as the firmware has been preloaded for the
> + * sanity check to be able to parse it for the resource table.
> + */
This comment is very confusing - please consider refactoring.
> + if (ddata->fw_loaded)
> + return 0;
> +
I'm not sure about keeping a flag to indicate the status of the loaded firmware.
It is not done for the non-secure method, I don't see why it would be needed for
the secure one.
> + ret = tee_rproc_load_fw(ddata->trproc, fw);
> + if (ret)
> + return ret;
> + ddata->fw_loaded = true;
> +
> + /* Update the resource table parameters. */
> + if (rproc_tee_get_rsc_table(ddata->trproc)) {
> + /* No resource table: reset the related fields. */
> + rproc->cached_table = NULL;
> + rproc->table_ptr = NULL;
> + rproc->table_sz = 0;
> + }
> +
> + return 0;
> +}
> +
> +static struct resource_table *
> +stm32_rproc_tee_elf_find_loaded_rsc_table(struct rproc *rproc,
> + const struct firmware *fw)
> +{
> + struct stm32_rproc *ddata = rproc->priv;
> +
> + return tee_rproc_get_loaded_rsc_table(ddata->trproc);
> +}
> +
> +static int stm32_rproc_tee_start(struct rproc *rproc)
> +{
> + struct stm32_rproc *ddata = rproc->priv;
> +
> + return tee_rproc_start(ddata->trproc);
> +}
> +
> +static int stm32_rproc_tee_attach(struct rproc *rproc)
> +{
> + /* Nothing to do, remote proc already started by the secured context. */
> + return 0;
> +}
> +
> +static int stm32_rproc_tee_stop(struct rproc *rproc)
> +{
> + struct stm32_rproc *ddata = rproc->priv;
> + int err;
> +
> + stm32_rproc_request_shutdown(rproc);
> +
> + err = tee_rproc_stop(ddata->trproc);
> + if (err)
> + return err;
> +
> + ddata->fw_loaded = false;
> +
> + return stm32_rproc_release(rproc);
> +}
> +
> static int stm32_rproc_prepare(struct rproc *rproc)
> {
> struct device *dev = rproc->dev.parent;
> @@ -319,7 +410,14 @@ static int stm32_rproc_prepare(struct rproc *rproc)
>
> static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
> {
> - if (rproc_elf_load_rsc_table(rproc, fw))
> + struct stm32_rproc *ddata = rproc->priv;
> + int ret;
> +
> + if (ddata->trproc)
> + ret = rproc_tee_get_rsc_table(ddata->trproc);
> + else
> + ret = rproc_elf_load_rsc_table(rproc, fw);
> + if (ret)
> dev_warn(&rproc->dev, "no resource table found for this firmware\n");
>
> return 0;
> @@ -693,8 +791,22 @@ static const struct rproc_ops st_rproc_ops = {
> .get_boot_addr = rproc_elf_get_boot_addr,
> };
>
> +static const struct rproc_ops st_rproc_tee_ops = {
> + .prepare = stm32_rproc_prepare,
> + .start = stm32_rproc_tee_start,
> + .stop = stm32_rproc_tee_stop,
> + .attach = stm32_rproc_tee_attach,
> + .kick = stm32_rproc_kick,
> + .parse_fw = stm32_rproc_parse_fw,
> + .find_loaded_rsc_table = stm32_rproc_tee_elf_find_loaded_rsc_table,
> + .get_loaded_rsc_table = stm32_rproc_get_loaded_rsc_table,
> + .sanity_check = stm32_rproc_tee_elf_sanity_check,
> + .load = stm32_rproc_tee_elf_load,
> +};
> +
> static const struct of_device_id stm32_rproc_match[] = {
> - { .compatible = "st,stm32mp1-m4" },
> + {.compatible = "st,stm32mp1-m4",},
> + {.compatible = "st,stm32mp1-m4-tee",},
> {},
> };
> MODULE_DEVICE_TABLE(of, stm32_rproc_match);
> @@ -853,6 +965,7 @@ static int stm32_rproc_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct stm32_rproc *ddata;
> struct device_node *np = dev->of_node;
> + struct tee_rproc *trproc = NULL;
> struct rproc *rproc;
> unsigned int state;
> int ret;
> @@ -861,11 +974,31 @@ static int stm32_rproc_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
> - if (!rproc)
> - return -ENOMEM;
> + if (of_device_is_compatible(np, "st,stm32mp1-m4-tee")) {
> + trproc = tee_rproc_register(dev, STM32_MP1_M4_PROC_ID);
> + if (IS_ERR(trproc)) {
> + dev_err_probe(dev, PTR_ERR(trproc),
> + "signed firmware not supported by TEE\n");
> + return PTR_ERR(trproc);
> + }
> + /*
> + * Delegate the firmware management to the secure context.
> + * The firmware loaded has to be signed.
> + */
> + dev_info(dev, "Support of signed firmware only\n");
Not sure what this adds. Please remove.
> + }
> + rproc = rproc_alloc(dev, np->name,
> + trproc ? &st_rproc_tee_ops : &st_rproc_ops,
> + NULL, sizeof(*ddata));
> + if (!rproc) {
> + ret = -ENOMEM;
> + goto free_tee;
> + }
>
> ddata = rproc->priv;
> + ddata->trproc = trproc;
> + if (trproc)
> + trproc->rproc = rproc;
>
> rproc_coredump_set_elf_info(rproc, ELFCLASS32, EM_NONE);
>
> @@ -916,6 +1049,10 @@ static int stm32_rproc_probe(struct platform_device *pdev)
> device_init_wakeup(dev, false);
> }
> rproc_free(rproc);
> +free_tee:
> + if (trproc)
> + tee_rproc_unregister(trproc);
> +
> return ret;
> }
>
> @@ -937,6 +1074,8 @@ static void stm32_rproc_remove(struct platform_device *pdev)
> device_init_wakeup(dev, false);
> }
> rproc_free(rproc);
> + if (ddata->trproc)
> + tee_rproc_unregister(ddata->trproc);
> }
>
> static int stm32_rproc_suspend(struct device *dev)
> --
> 2.25.1
>
