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From:   Alexandre Courbot <acourbot@chromium.org>
Date:   Tue, 28 Aug 2018 14:43:29 +0900
Message-ID: <CAPBb6MUGQKOvNBL3RvnJu-MZ=DQzp1WemWChk2NZpbuWx2kGcw@mail.gmail.com>
Subject: Re: [PATCH v6 1/4] venus: firmware: add routine to reset ARM9
To:     Stanimir Varbanov <stanimir.varbanov@linaro.org>
Cc:     vgarodia@codeaurora.org, Hans Verkuil <hverkuil@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>, robh@kernel.org,
        mark.rutland@arm.com, Andy Gross <andy.gross@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>, bjorn.andersson@linaro.org,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
        devicetree@vger.kernel.org
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On Mon, Aug 27, 2018 at 7:56 PM Stanimir Varbanov
<stanimir.varbanov@linaro.org> wrote:
>
>
>
> On 08/27/2018 06:04 AM, Alexandre Courbot wrote:
> > On Fri, Aug 24, 2018 at 5:57 PM Stanimir Varbanov
> > <stanimir.varbanov@linaro.org> wrote:
> >>
> >> Hi Alex,
> >>
> >> On 08/24/2018 10:38 AM, Alexandre Courbot wrote:
> >>> On Thu, Aug 23, 2018 at 11:29 PM Vikash Garodia <vgarodia@codeaurora.org> wrote:
> >>>>
> >>>> Add routine to reset the ARM9 and brings it out of reset. Also
> >>>> abstract the Venus CPU state handling with a new function. This
> >>>> is in preparation to add PIL functionality in venus driver.
> >>>>
> >>>> Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>
> >>>> ---
> >>>>  drivers/media/platform/qcom/venus/core.h         |  2 ++
> >>>>  drivers/media/platform/qcom/venus/firmware.c     | 33 ++++++++++++++++++++++++
> >>>>  drivers/media/platform/qcom/venus/firmware.h     | 11 ++++++++
> >>>>  drivers/media/platform/qcom/venus/hfi_venus.c    | 13 +++-------
> >>>>  drivers/media/platform/qcom/venus/hfi_venus_io.h |  7 +++++
> >>>>  5 files changed, 57 insertions(+), 9 deletions(-)
> >>>>
> >>>> diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
> >>>> index 2f02365..dfd5c10 100644
> >>>> --- a/drivers/media/platform/qcom/venus/core.h
> >>>> +++ b/drivers/media/platform/qcom/venus/core.h
> >>>> @@ -98,6 +98,7 @@ struct venus_caps {
> >>>>   * @dev:               convenience struct device pointer
> >>>>   * @dev_dec:   convenience struct device pointer for decoder device
> >>>>   * @dev_enc:   convenience struct device pointer for encoder device
> >>>> + * @no_tz:     a flag that suggests presence of trustzone
> >>>>   * @lock:      a lock for this strucure
> >>>>   * @instances: a list_head of all instances
> >>>>   * @insts_count:       num of instances
> >>>> @@ -129,6 +130,7 @@ struct venus_core {
> >>>>         struct device *dev;
> >>>>         struct device *dev_dec;
> >>>>         struct device *dev_enc;
> >>>> +       bool no_tz;
> >>>>         struct mutex lock;
> >>>>         struct list_head instances;
> >>>>         atomic_t insts_count;
> >>>> diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
> >>>> index c4a5778..a9d042e 100644
> >>>> --- a/drivers/media/platform/qcom/venus/firmware.c
> >>>> +++ b/drivers/media/platform/qcom/venus/firmware.c
> >>>> @@ -22,10 +22,43 @@
> >>>>  #include <linux/sizes.h>
> >>>>  #include <linux/soc/qcom/mdt_loader.h>
> >>>>
> >>>> +#include "core.h"
> >>>>  #include "firmware.h"
> >>>> +#include "hfi_venus_io.h"
> >>>>
> >>>>  #define VENUS_PAS_ID                   9
> >>>>  #define VENUS_FW_MEM_SIZE              (6 * SZ_1M)
> >>>
> >>> This is making a strong assumption about the size of the FW memory
> >>> region, which in practice is not always true (I had to reduce it to
> >>> 5MB). How about having this as a member of venus_core, which is
> >>
> >> Why you reduced to 5MB? Is there an issue with 6MB or you don't want to
> >> waste reserved memory?
> >
> > The DT layout of our board only has 5MB reserved for Venus.
> >
> >>> initialized in venus_load_fw() from the actual size of the memory
> >>> region? You could do this as an extra patch that comes before this
> >>> one.
> >>>
> >>
> >> The size is 6MB by historical reasons and they are no more valid, so I
> >> think we could safely decrease to 5MB. I could prepare a patch for that.
> >
> > Whether we settle with 6MB or 5MB, that size remains arbitrary and not
> > based on the actual firmware size. And __qcom_mdt_load() does check
>
> If we go with 5MB it will not be arbitrary, cause all firmware we have
> support to are expecting that size of memory.
>
> > that the firmware fits the memory area. So I don't understand what
> > extra safety is added by ensuring the memory region is larger than a
> > given number of megabytes?
> >
>
> OK, is that fine for you? Drop size and check does memory region size is
> big enough to contain the firmware.
>
> diff --git a/drivers/media/platform/qcom/venus/firmware.c
> b/driver/media/platform/qcom/venus/firmware.c
> index c4a577848dd7..9bf0d21e02d4 100644
> --- a/drivers/media/platform/qcom/venus/firmware.c
> +++ b/drivers/media/platform/qcom/venus/firmware.c
> @@ -25,7 +25,6 @@
>  #include "firmware.h"
>
>  #define VENUS_PAS_ID                   9
> -#define VENUS_FW_MEM_SIZE              (6 * SZ_1M)
>
>  int venus_boot(struct device *dev, const char *fwname)
>  {
> @@ -54,25 +53,28 @@ int venus_boot(struct device *dev, const char *fwname)
>         mem_phys = r.start;
>         mem_size = resource_size(&r);
>
> -       if (mem_size < VENUS_FW_MEM_SIZE)
> -               return -EINVAL;
> -
> -       mem_va = memremap(r.start, mem_size, MEMREMAP_WC);
> -       if (!mem_va) {
> -               dev_err(dev, "unable to map memory region: %pa+%zx\n",
> -                       &r.start, mem_size);
> -               return -ENOMEM;
> -       }
> -
>         ret = request_firmware(&mdt, fwname, dev);
>         if (ret < 0)
> -               goto err_unmap;
> +               return ret;
>
>         fw_size = qcom_mdt_get_size(mdt);
>         if (fw_size < 0) {
>                 ret = fw_size;
>                 release_firmware(mdt);
> -               goto err_unmap;
> +               return ret;
> +       }
> +
> +       if (mem_size < fw_size) {
> +               release_firmware(mdt);
> +               return -EINVAL;
> +       }
> +
> +       mem_va = memremap(r.start, mem_size, MEMREMAP_WC);
> +       if (!mem_va) {
> +               release_firmware(mdt);
> +               dev_err(dev, "unable to map memory region: %pa+%zx\n",
> +                       &r.start, mem_size);
> +               return -ENOMEM;
>         }

That looks reasonable to me, at least if the firmware does not require
extra memory beyond its reported size. But you know the firmware
better, so your call! :)