On Fri, Feb 23, 2024 at 02:54:13PM +0100, Arnaud POULIQUEN wrote:
> Hello Mathieu,
>
> On 2/22/24 20:02, Mathieu Poirier wrote:
> > Hi,
> >
> > On Wed, Feb 14, 2024 at 06:21:27PM +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.
> >>
> >> A new "to_attach" field is introduced to differentiate the use cases
> >> "firmware loaded by the boot stage" and "firmware loaded by the TEE".
> >>
> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
> >> ---
> >> V2 to V3 update:
> >> - remove stm32_rproc_tee_elf_sanity_check(), stm32_rproc_tee_elf_load()
> >> stm32_rproc_tee_elf_find_loaded_rsc_table() and stm32_rproc_tee_start() that are bnow unused
> >> - use new rproc::alt_boot field to sepcify that the alternate fboot method is used
> >> - use stm32_rproc::to_attach field to differenciate attch mode from remoteproc tee boot mode.
> >> - remove the used of stm32_rproc::fw_loaded
> >> ---
> >> drivers/remoteproc/stm32_rproc.c | 85 +++++++++++++++++++++++++++++---
> >> 1 file changed, 79 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> >> index fcc0001e2657..9cfcf66462e0 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 to_attach;
> >> + struct tee_rproc *trproc;
> >> void __iomem *rsc_va;
> >> };
> >>
> >> @@ -253,10 +259,30 @@ static int stm32_rproc_release(struct rproc *rproc)
> >> return err;
> >> }
> >> }
> >> + ddata->to_attach = false;
> >>
> >> return err;
> >> }
> >>
> >> +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)
> >> +{
> >> + 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;
> >> @@ -637,10 +663,14 @@ stm32_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz)
> >> {
> >> struct stm32_rproc *ddata = rproc->priv;
> >> struct device *dev = rproc->dev.parent;
> >> + struct tee_rproc *trproc = ddata->trproc;
> >> phys_addr_t rsc_pa;
> >> u32 rsc_da;
> >> int err;
> >>
> >> + if (trproc && !ddata->to_attach)
> >> + return tee_rproc_get_loaded_rsc_table(rproc, table_sz);
> >> +
> >
> > Why do we need a flag at all? Why can't st_rproc_tee_ops::get_loaded_rsc_table
> > be set to tee_rproc_get_loaded_rsc_table()?
>
>
> This function is used to retrieve the address of the resource table in 3 cases
> - attach to a firmware started by the boot loader (U-boot).
> - load of the firmware by OP-TEE.
> - crash recovery on a signed firmware started by the boot loader.
>
> The flag is used to differentiate the attch from the other uses cases
> For instance we support this use case.
> 1) attach to the firmware on boot
> 2) crash during runtime
> 2a) stop the firmware by OP-TEE( ddata->to_attach set to 0)
> 2b) load the firmware by OP-TEE
> 2c) get the loaded resource table from OP-TEE (we can not guaranty
> that the firmware loaded on recovery is the same)
> 2d) restart the firmware by OP-TEE
This is not maintainable and needs to be broken down into smaller
building blocks. The introduction of tee_rproc_parse_fw() should help dealing
with some of the complexity.
>
> >
> >> /* The resource table has already been mapped, nothing to do */
> >> if (ddata->rsc_va)
> >> goto done;
> >> @@ -693,8 +723,20 @@ 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,
> >> + .attach = stm32_rproc_tee_attach,
> >> + .kick = stm32_rproc_kick,
> >> + .get_loaded_rsc_table = stm32_rproc_get_loaded_rsc_table,
> >> + .find_loaded_rsc_table = tee_rproc_find_loaded_rsc_table,
> >> + .load = tee_rproc_load_fw,
> >> +};
> >> +
> >> 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 +895,7 @@ 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;
> >> @@ -861,12 +904,33 @@ 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;
> >
> > This patch doesn't apply to rproc-next - please rebase.
>
> Yes, sure. I forgot to mention in my cover letter that my series has been
> applied and tested on 841c35169323 (Linux 6.8-rc4).
>
> >
> >
> >> + 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.
> >> + */
> >> + 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);
> >> + }
> >> + }
> >>
> >> - ddata = rproc->priv;
> >> + 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;
> >
> > My opinion hasn't changed from the previous patchet, i.e tee_rproc should be
> > folded in struct rproc as rproc::tee_interface.
>
> Sure, I will do it in next version
>
> >
> > More comments to come shortly...
> >
>
> Thanks!
> Arnaud
>
> >> + if (trproc) {
> >> + rproc->alt_boot = true;
> >> + trproc->rproc = rproc;
> >> + }
> >> rproc_coredump_set_elf_info(rproc, ELFCLASS32, EM_NONE);
> >>
> >> ret = stm32_rproc_parse_dt(pdev, ddata, &rproc->auto_boot);
> >> @@ -881,8 +945,10 @@ static int stm32_rproc_probe(struct platform_device *pdev)
> >> if (ret)
> >> goto free_rproc;
> >>
> >> - if (state == M4_STATE_CRUN)
> >> + if (state == M4_STATE_CRUN) {
> >> rproc->state = RPROC_DETACHED;
> >> + ddata->to_attach = true;
> >> + }
> >>
> >> rproc->has_iommu = false;
> >> ddata->workqueue = create_workqueue(dev_name(dev));
> >> @@ -916,6 +982,10 @@ 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;
> >> }
> >>
> >> @@ -923,6 +993,7 @@ static void stm32_rproc_remove(struct platform_device *pdev)
> >> {
> >> struct rproc *rproc = platform_get_drvdata(pdev);
> >> struct stm32_rproc *ddata = rproc->priv;
> >> + struct tee_rproc *trproc = ddata->trproc;
> >> struct device *dev = &pdev->dev;
> >>
> >> if (atomic_read(&rproc->power) > 0)
> >> @@ -937,6 +1008,8 @@ static void stm32_rproc_remove(struct platform_device *pdev)
> >> device_init_wakeup(dev, false);
> >> }
> >> rproc_free(rproc);
> >> + if (trproc)
> >> + tee_rproc_unregister(trproc);
> >> }
> >>
> >> static int stm32_rproc_suspend(struct device *dev)
> >> --
> >> 2.25.1
> >>
> >
