On Tue, Mar 26, 2024 at 08:31:33PM +0100, Arnaud POULIQUEN wrote:
>
>
> On 3/25/24 17:51, Mathieu Poirier wrote:
> > On Fri, Mar 08, 2024 at 03:47:08PM +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>
> >> ---
> >> Updates from V3:
> >> - remove support of the attach use case. Will be addressed in a separate
> >> thread,
> >> - add st_rproc_tee_ops::parse_fw ops,
> >> - inverse call of devm_rproc_alloc()and tee_rproc_register() to manage cross
> >> reference between the rproc struct and the tee_rproc struct in tee_rproc.c.
> >> ---
> >> drivers/remoteproc/stm32_rproc.c | 60 +++++++++++++++++++++++++++++---
> >> 1 file changed, 56 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> >> index 8cd838df4e92..13df33c78aa2 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 */
> >
> > Why is this the case? At least from the kernel side it is possible to call
> > tee_rproc_register() with any kind of value, why is there a need to be any
> > kind of alignment with the TEE?
>
>
> The use of the proc_id is to identify a processor in case of multi co-processors.
>
That is well understood.
> For instance we can have a system with A DSP and a modem. We would use the same
> TEE service, but
That too.
> the TEE driver will probably be different, same for the signature key.
What TEE driver are we talking about here?
> In such case the proc ID allows to identify the the processor you want to address.
>
That too is well understood, but there is no alignment needed with the TEE, i.e
the TEE application is not expecting a value of '0'. We could set
STM32_MP1_M4_PROC_ID to 0xDEADBEEF and things would work. This driver won't go
anywhere for as long as it is not the case.
>
> >
> >> +#define STM32_MP1_M4_PROC_ID 0
> >> +
> >> struct stm32_syscon {
> >> struct regmap *map;
> >> u32 reg;
> >> @@ -257,6 +261,19 @@ static int stm32_rproc_release(struct rproc *rproc)
> >> return 0;
> >> }
> >>
> >> +static int stm32_rproc_tee_stop(struct rproc *rproc)
> >> +{
> >> + int err;
> >> +
> >> + stm32_rproc_request_shutdown(rproc);
> >> +
> >> + err = tee_rproc_stop(rproc);
> >> + if (err)
> >> + return err;
> >> +
> >> + return stm32_rproc_release(rproc);
> >> +}
> >> +
> >> static int stm32_rproc_prepare(struct rproc *rproc)
> >> {
> >> struct device *dev = rproc->dev.parent;
> >> @@ -693,8 +710,19 @@ 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 = tee_rproc_start,
> >> + .stop = stm32_rproc_tee_stop,
> >> + .kick = stm32_rproc_kick,
> >> + .load = tee_rproc_load_fw,
> >> + .parse_fw = tee_rproc_parse_fw,
> >> + .find_loaded_rsc_table = tee_rproc_find_loaded_rsc_table,
> >> +};
> >> +
> >> 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 +881,7 @@ 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;
> >> @@ -861,9 +890,26 @@ static int stm32_rproc_probe(struct platform_device *pdev)
> >> if (ret)
> >> return ret;
> >>
> >> - rproc = devm_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")) {
> >> + /*
> >> + * Delegate the firmware management to the secure context.
> >> + * The firmware loaded has to be signed.
> >> + */
> >> + rproc = devm_rproc_alloc(dev, np->name, &st_rproc_tee_ops, NULL, sizeof(*ddata));
> >> + if (!rproc)
> >> + return -ENOMEM;
> >> +
> >> + trproc = tee_rproc_register(dev, rproc, 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);
> >> + }
> >> + } else {
> >> + rproc = devm_rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
> >> + if (!rproc)
> >> + return -ENOMEM;
> >> + }
> >>
> >> ddata = rproc->priv;
> >>
> >> @@ -915,6 +961,9 @@ static int stm32_rproc_probe(struct platform_device *pdev)
> >> dev_pm_clear_wake_irq(dev);
> >> device_init_wakeup(dev, false);
> >> }
> >> + if (trproc)
> >
> > if (rproc->tee_interface)
> >
> >
> > I am done reviewing this set.
>
> Thank for your review!
> Arnaud
>
> >
> > Thanks,
> > Mathieu
> >
> >> + tee_rproc_unregister(trproc);
> >> +
> >> return ret;
> >> }
> >>
> >> @@ -935,6 +984,9 @@ static void stm32_rproc_remove(struct platform_device *pdev)
> >> dev_pm_clear_wake_irq(dev);
> >> device_init_wakeup(dev, false);
> >> }
> >> + if (rproc->tee_interface)
> >> + tee_rproc_unregister(rproc->tee_interface);
> >> +
> >> }
> >>
> >> static int stm32_rproc_suspend(struct device *dev)
> >> --
> >> 2.25.1
> >>
