On Thu, 22 Sept 2022 at 14:22, Etienne Carriere <etienne.carri...@linaro.org> wrote: > > Hello Patrick and all, > > On Mon, 19 Sept 2022 at 16:49, Patrick DELAUNAY > <patrick.delau...@foss.st.com> wrote: > > > > > > Hi Simon, > > > > On 9/12/22 20:31, Simon Glass wrote: > > > 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 > > >>>>>> whichwe 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-TEETA > > >>>>>> */ > > >>>>>> - 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? > > > > > > The tee bus is supported in Linux kernel (each TA have a UUID and > > is discoverable by the TEE driver). > > > > see drivers/tee/optee/core.c::optee_bus_scan() > > and "struct tee_client_driver" with TA UUID > > It wasn't supported in U-Boot is the first TEE/OP-TEE driver implementation > > > > => TA support was hardcoded, under the associated CONFIG > > and the probe failed when the TA is not present. > > for example, I add this binding for TA_RNG in drivers/rng/optee_rng.c > > > > The TEE bus feature is added by the Etienne in the serie [1]. > > This bus is more flexible and avoid OP-TEE to dynamically modify the > > device tree > > to add/remove the supported SW component (TA support are activated > > during OP-TEE > > compilation) as the binding is managed dynamically in OP-TEE as it is > > done in Linux. > > > > For information, on STM32MP15 platform, I have the trace "can't open > > session:" for > > RNG TA for each 'rng' command when this TA is not supported in OP-TEE but > > OP-TEE RNG driver is activated in U-Boot, because the driver is binding. > > > > [1] drivers: tee: optee: remove unused probe local variable > > > > http://patchwork.ozlabs.org/project/uboot/list/?series=311351&state=* > > > > > This appears to be a Linaro binding, so you should be able to update > > > it easily enough. > > > > > Discussing with Patrick, he made a suggestion and showed me I was > wrong in OP-TEE tee-supplicant enumeration constraints in U-Boot. > OP-TEE exposes 2 levels of service discovery, so-called devices > enumeration and device-with-supplicant enumeration. The later are > OP-TEE services that depend on RPC service exposed to OP-TEE by in the > caller OS (U-Boot or Linux kernel). The former are services without > such dependencies. When i posted OP-TEE services discovery in U-Boot, > I made U-Boot to enumerate OP-TEE "devices" (without tee-suppl. > dependencies). > I made it intentionally as U-Boot tee-supplicant does not implement > all OP-TEE RPC services as Linux kernel. Since FTPM TA service relies > on tee-supplicant support, it is not enumerated/discovered. > > The point is the U-Boot tee-suppl. does implement the few RPC services > FTPM TA needs (that are memory allocation and RPMB access). > So Patrick argued that U-Boot can as well enumerate OP-TEE service > *with* tee-suppl. devices. The optee ftpm driver can register to this > service discovery and will operate properly. > What puzzled me was that discovery of OP-TEE services that require > tee-suppl. services not available in U-Boot would end in a failure of > the service, but as Patrick rightly said that it makes no sense for > one of add implement u-boot a driver for an OP-TEE service if that > service lacks some U-Boot tee-suppl. supports.
+1 > > All in one, my apologies Ilias for this mistake. A change in > tee/optee/core.c to also bind services enumerated by OP-TEE command > PTA_CMD_GET_DEVICES_SUPPL should enable full dynamic discovery of > functional FTPM TA service. I'll post a change for that. > I think that should be gated under CONFIG_SUPPORT_EMMC_RPMB as if that's unavailable FTPM TA service can't be functional. -Sumit > Regards, > Etienne > > > > Regards, > > > Simon > > > > Regards > > Patrick