Hi Ilias, On Wed, 7 Sept 2022 at 15:32, Ilias Apalodimas <ilias.apalodi...@linaro.org> wrote: > > Hi Simon, > > On Thu, 8 Sept 2022 at 00:11, Simon Glass <s...@chromium.org> wrote: > > > > Hi Ilias, > > > > On Tue, 6 Sept 2022 at 15:23, Ilias Apalodimas > > <ilias.apalodi...@linaro.org> wrote: > > > > > > Hi Simon, > > > > > > On Tue, Sep 06, 2022 at 03:18:28PM -0600, Simon Glass wrote: > > > > Hi, > > > > > > > > On Tue, 6 Sept 2022 at 03:37, Ilias Apalodimas > > > > <ilias.apalodi...@linaro.org> wrote: > > > > > > > > > > Late versions of OP-TEE support a pseudo bus. TAs that behave as > > > > > hardware blocks (e.g TPM, RNG etc) present themselves on a bus which > > > > > we can > > > > > scan. Unfortunately U-Boot doesn't support that yet. It's worth > > > > > noting > > > > > that we already have a workaround for RNG. The details are in > > > > > commit 70812bb83da6 ("tee: optee: bind rng optee driver") > > > > > > > > > > So let's add a list of devices based on U-Boot Kconfig options that > > > > > we will > > > > > scan until we properly implement the tee-bus functionality. > > > > > > > > > > While at it change the behaviour of the tee core itself wrt to device > > > > > binding. If some device binding fails, print a warning instead of > > > > > disabling OP-TEE. > > > > > > > > > > Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org> > > > > > Reviewed-by: Jens Wiklander <jens.wiklan...@linaro.org> > > > > > Reviewed-by: Etienne Carriere <etienne.carri...@linaro.org> > > > > > --- > > > > > Changes since v3: > > > > > - Use NULL instead of a child ptr on device_bind_driver(), since it's > > > > > not > > > > > really needed > > > > > - Changed the style of the optee_bus_probe[] definition to > > > > > {.drv_name = xxx, .dev_name = yyy } > > > > > > > > > > Changes since v2: > > > > > - Fixed typo on driver name ftpm-tee -> ftpm_tee > > > > > > > > > > Changes since v1: > > > > > - remove a macro and use ARRAY_SIZE directly > > > > > drivers/tee/optee/core.c | 24 +++++++++++++++++++----- > > > > > 1 file changed, 19 insertions(+), 5 deletions(-) > > > > > > > > > > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c > > > > > index a89d62aaf0b3..c201a4635e6b 100644 > > > > > --- a/drivers/tee/optee/core.c > > > > > +++ b/drivers/tee/optee/core.c > > > > > @@ -31,6 +31,18 @@ struct optee_pdata { > > > > > optee_invoke_fn *invoke_fn; > > > > > }; > > > > > > > > > > +static const struct { > > > > > + const char *drv_name; > > > > > + const char *dev_name; > > > > > +} optee_bus_probe[] = { > > > > > +#ifdef CONFIG_RNG_OPTEE > > > > > + { .drv_name = "optee-rng", .dev_name = "optee-rng" }, > > > > > +#endif > > > > > +#ifdef CONFIG_TPM2_FTPM_TEE > > > > > + { .drv_name = "ftpm_tee", .dev_name = "ftpm_tee" }, > > > > > +#endif > > > > > +}; > > > > > + > > > > > struct rpc_param { > > > > > u32 a0; > > > > > u32 a1; > > > > > @@ -642,8 +654,7 @@ static int optee_probe(struct udevice *dev) > > > > > { > > > > > struct optee_pdata *pdata = dev_get_plat(dev); > > > > > u32 sec_caps; > > > > > - struct udevice *child; > > > > > - int ret; > > > > > + int ret, i; > > > > > > > > > > if (!is_optee_api(pdata->invoke_fn)) { > > > > > dev_err(dev, "OP-TEE api uid mismatch\n"); > > > > > @@ -672,10 +683,13 @@ static int optee_probe(struct udevice *dev) > > > > > * in U-Boot, the discovery of TA on the TEE bus is not > > > > > supported: > > > > > * only bind the drivers associated to the supported OP-TEE TA > > > > > */ > > > > > - if (IS_ENABLED(CONFIG_RNG_OPTEE)) { > > > > > - ret = device_bind_driver(dev, "optee-rng", > > > > > "optee-rng", &child); > > > > > + > > > > > + for (i = 0; i < ARRAY_SIZE(optee_bus_probe); i++) { > > > > > + ret = device_bind_driver(dev, > > > > > optee_bus_probe[i].drv_name, > > > > > + optee_bus_probe[i].dev_name, > > > > > NULL); > > > > > if (ret) > > > > > - return ret; > > > > > + dev_warn(dev, "Failed to bind device %s\n", > > > > > + optee_bus_probe[i].dev_name); > > > > > > > > Please add device tree nodes for these and all this code can go away. > > > > > > That's the exact opposite of what the commit message describes. OP-TEE > > > supports a scannable bus ifor TAs that behave like hardware blocks and > > > doesn't need a DT entry. Since it's really the TAs compilation decision > > > to support that or not having them as a DT node is not always the right > > > choice. > > > > This is continuing the perversion of how things are supposed to work > > in driver model. > > Which is not the only thing we need to keep in mind though. > > > > > We need to talk about this because it is simply the wrong way to be > > approaching this. > > This is already part of other software components though, e.g it's > already in the kernel. So I don't think it's the wrong approach. > > > There is nothing wrong with putting things in the DT > > and this is how U-Boot works. For now, please create a binding and get > > it reviewed. You don't need all the internal objects but you do need > > an OP-TEE driver and node, as we have with PCI. > > Some things *are* working without a DT entry. You had similar > concerns on FF-A (where you requested a DT node again) and people gave > the exact same response. As long as a bus is scanable in any way, > it's preferable to than adding a DT entry. Moreover this code does > not prevent anyone from adding a DT entry. > > To make things even worse if the TA is compiled as 'scanable' and has > a DT entry, it might cause issues down the road when being probed by > the kernel. So really this is just a patch that makes u-boot behave > and plug in properly to the rest of the ecosystem
Calling device_bind() is supposed to be used in extremis. I don't see any scanning of an OP-TEE bus here. I just see it binding two child devices which are hard-coded in U-Boot. What am I missing? This appears to be a Linaro binding, so you should be able to update it easily enough. Regards, Simon