Messages in this thread | | | Subject | Re: [PATCH 3/3] remoteproc/k3-dsp: Add support for L2RAM loading on C66x DSPs | From | Suman Anna <> | Date | Wed, 13 May 2020 17:31:50 -0500 |
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Hi Mathieu,
On 4/28/20 3:09 PM, Mathieu Poirier wrote: > On Tue, 28 Apr 2020 at 13:58, Mathieu Poirier > <mathieu.poirier@linaro.org> wrote: >> >> On Wed, Mar 25, 2020 at 03:18:39PM -0500, Suman Anna wrote: >>> The resets for the DSP processors on K3 SoCs are managed through the >>> Power and Sleep Controller (PSC) module. Each DSP typically has two >>> resets - a global module reset for powering on the device, and a local >>> reset that affects only the CPU while allowing access to the other >>> sub-modules within the DSP processor sub-systems. >>> >>> The C66x DSPs have two levels of internal RAMs that can be used to >>> boot from, and the firmware loading into these RAMs require the >>> local reset to be asserted with the device powered on/enabled using >>> the module reset. Enhance the K3 DSP remoteproc driver to add support >>> for loading into the internal RAMs. The local reset is deasserted on >>> SoC power-on-reset, so logic has to be added in probe in remoteproc >>> mode to balance the remoteproc state-machine. >>> >>> Note that the local resets are a no-op on C71x cores, and the hardware >>> does not supporting loading into its internal RAMs. >>> >>> Signed-off-by: Suman Anna <s-anna@ti.com> >>> --- >>> drivers/remoteproc/ti_k3_dsp_remoteproc.c | 82 +++++++++++++++++++++++ >>> 1 file changed, 82 insertions(+) >>> >>> diff --git a/drivers/remoteproc/ti_k3_dsp_remoteproc.c b/drivers/remoteproc/ti_k3_dsp_remoteproc.c >>> index fd0d84f46f90..7b712ef74611 100644 >>> --- a/drivers/remoteproc/ti_k3_dsp_remoteproc.c >>> +++ b/drivers/remoteproc/ti_k3_dsp_remoteproc.c >>> @@ -175,6 +175,9 @@ static int k3_dsp_rproc_reset(struct k3_dsp_rproc *kproc) >>> return ret; >>> } >>> >>> + if (kproc->data->uses_lreset) >>> + return ret; >>> + >>> ret = kproc->ti_sci->ops.dev_ops.put_device(kproc->ti_sci, >>> kproc->ti_sci_id); >>> if (ret) { >>> @@ -192,6 +195,9 @@ static int k3_dsp_rproc_release(struct k3_dsp_rproc *kproc) >>> struct device *dev = kproc->dev; >>> int ret; >>> >>> + if (kproc->data->uses_lreset) >>> + goto lreset; >>> + >>> ret = kproc->ti_sci->ops.dev_ops.get_device(kproc->ti_sci, >>> kproc->ti_sci_id); >>> if (ret) { >>> @@ -199,6 +205,7 @@ static int k3_dsp_rproc_release(struct k3_dsp_rproc *kproc) >>> return ret; >>> } >>> >>> +lreset: >>> ret = reset_control_deassert(kproc->reset); >>> if (ret) { >>> dev_err(dev, "local-reset deassert failed, ret = %d\n", ret); >>> @@ -210,6 +217,63 @@ static int k3_dsp_rproc_release(struct k3_dsp_rproc *kproc) >>> return ret; >>> } >>> >>> +/* >>> + * The C66x DSP cores have a local reset that affects only the CPU, and a >>> + * generic module reset that powers on the device and allows the DSP internal >>> + * memories to be accessed while the local reset is asserted. This function is >>> + * used to release the global reset on C66x DSPs to allow loading into the DSP >>> + * internal RAMs. The .prepare() ops is invoked by remoteproc core before any >>> + * firmware loading, and is followed by the .start() ops after loading to >>> + * actually let the C66x DSP cores run. The local reset on C71x cores is a >>> + * no-op and the global reset cannot be released on C71x cores until after >>> + * the firmware images are loaded, so this function does nothing for C71x cores. >>> + */ >>> +static int k3_dsp_rproc_prepare(struct rproc *rproc) >>> +{ >>> + struct k3_dsp_rproc *kproc = rproc->priv; >>> + struct device *dev = kproc->dev; >>> + int ret; >>> + >>> + /* local reset is no-op on C71x processors */ >>> + if (!kproc->data->uses_lreset) >>> + return 0; >> >> In k3_dsp_rproc_release() the condition is "if (kproc->data->uses_lreset)" and >> here it is the opposite, which did a good job at getting me confused.
Do you prefer I add a comment there? It needs to bail out there since the get_device portion would be executed here.
>> >> Taking a step back, I assume c71 DSPs will have their own k3_dsp_dev_data where >> the users_lreset flag will be false.
Yes.
In that case I think it would make the >> code easier to understand if the k3_dsp_rproc_ops was declared without the >> .prepare and .unprepare. In probe(), if data->uses_lreset is true then >> k3_dsp_rproc_prepare() and k3_dsp_rproc_unprepare() are set.
Yeah, ok, that will avoid the confusion and limit the prepare()/unprepare() only for C66 DSPs.
>> > > I forgot... Since this is a C71 related change, was there a reason to > lump it with the C66 set? If not I would simply move that to the C71 > work.
OK, I can remove this logic here, and add the prepare()/unprepare() conditionally for C66x in the C71 patch.
> >> I am done reviewing this set.
Thanks for all the review comments.
regards Suman
>> >> Thanks, >> Mathieu >> >>> + >>> + ret = kproc->ti_sci->ops.dev_ops.get_device(kproc->ti_sci, >>> + kproc->ti_sci_id); >>> + if (ret) >>> + dev_err(dev, "module-reset deassert failed, cannot enable internal RAM loading, ret = %d\n", >>> + ret); >>> + >>> + return ret; >>> +} >>> + >>> +/* >>> + * This function implements the .unprepare() ops and performs the complimentary >>> + * operations to that of the .prepare() ops. The function is used to assert the >>> + * global reset on applicable C66x cores. This completes the second portion of >>> + * powering down the C66x DSP cores. The cores themselves are only halted in the >>> + * .stop() callback through the local reset, and the .unprepare() ops is invoked >>> + * by the remoteproc core after the remoteproc is stopped to balance the global >>> + * reset. >>> + */ >>> +static int k3_dsp_rproc_unprepare(struct rproc *rproc) >>> +{ >>> + struct k3_dsp_rproc *kproc = rproc->priv; >>> + struct device *dev = kproc->dev; >>> + int ret; >>> + >>> + /* local reset is no-op on C71x processors */ >>> + if (!kproc->data->uses_lreset) >>> + return 0; >>> + >>> + ret = kproc->ti_sci->ops.dev_ops.put_device(kproc->ti_sci, >>> + kproc->ti_sci_id); >>> + if (ret) >>> + dev_err(dev, "module-reset assert failed, ret = %d\n", ret); >>> + >>> + return ret; >>> +} >>> + >>> /* >>> * Power up the DSP remote processor. >>> * >>> @@ -353,6 +417,8 @@ static void *k3_dsp_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len) >>> } >>> >>> static const struct rproc_ops k3_dsp_rproc_ops = { >>> + .prepare = k3_dsp_rproc_prepare, >>> + .unprepare = k3_dsp_rproc_unprepare, >>> .start = k3_dsp_rproc_start, >>> .stop = k3_dsp_rproc_stop, >>> .kick = k3_dsp_rproc_kick, >>> @@ -644,6 +710,22 @@ static int k3_dsp_rproc_probe(struct platform_device *pdev) >>> goto disable_clk; >>> } >>> >>> + /* >>> + * ensure the DSP local reset is asserted to ensure the DSP doesn't >>> + * execute bogus code in .prepare() when the module reset is released. >>> + */ >>> + if (data->uses_lreset) { >>> + ret = reset_control_status(kproc->reset); >>> + if (ret < 0) { >>> + dev_err(dev, "failed to get reset status, status = %d\n", >>> + ret); >>> + goto release_mem; >>> + } else if (ret == 0) { >>> + dev_warn(dev, "local reset is deasserted for device\n"); >>> + k3_dsp_rproc_reset(kproc); >>> + } >>> + } >>> + >>> ret = rproc_add(rproc); >>> if (ret) { >>> dev_err(dev, "failed to add register device with remoteproc core, status = %d\n", >>> -- >>> 2.23.0 >>>
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