Nouveau - Nov 2016 - [PATCH] gr: fallback to legacy paths during firmware lookup

Look for firmware files using the legacy ("nouveau/nvxx_fucxxxx") path
if they cannot be found in the new, "official" path. User setups were
broken by the switch, which is bad.

There are only 4 firmware files we may want to look up that way, so
hardcode them into the lookup function. All new firmware files should
use the standard "nvidia/<chip>/gr/" path.

Fixes: 8539b37acef7 ("drm/nouveau/gr: use NVIDIA-provided external
firmwares")
Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
---
 drm/nouveau/nvkm/engine/gr/gf100.c | 56 ++++++++++++++++++++++++++++++++++----
 1 file changed, 51 insertions(+), 5 deletions(-)

diff --git a/drm/nouveau/nvkm/engine/gr/gf100.c
b/drm/nouveau/nvkm/engine/gr/gf100.c
index 157919c788e6..9e65adbab21c 100644
--- a/drm/nouveau/nvkm/engine/gr/gf100.c
+++ b/drm/nouveau/nvkm/engine/gr/gf100.c
@@ -1756,24 +1756,70 @@ gf100_gr_ = {
 };
 
 int
+gf100_gr_ctor_fw_legacy(struct gf100_gr *gr, const char *fwname,
+			struct gf100_gr_fuc *fuc)
+{
+	struct nvkm_subdev *subdev = &gr->base.engine.subdev;
+	struct nvkm_device *device = subdev->device;
+	const struct firmware *fw;
+	char f[32];
+	int ret;
+
+	snprintf(f, sizeof(f), "nouveau/nv%02x_%s", device->chipset,
fwname);
+	ret = request_firmware(&fw, f, device->dev);
+	if (ret) {
+		snprintf(f, sizeof(f), "nouveau/%s", fwname);
+		ret = request_firmware(&fw, f, device->dev);
+		if (ret) {
+			nvkm_error(subdev, "failed to load %s\n", fwname);
+			return ret;
+		}
+	}
+
+	fuc->size = fw->size;
+	fuc->data = kmemdup(fw->data, fuc->size, GFP_KERNEL);
+	release_firmware(fw);
+	return (fuc->data != NULL) ? 0 : -ENOMEM;
+}
+
+int
 gf100_gr_ctor_fw(struct gf100_gr *gr, const char *fwname,
 		 struct gf100_gr_fuc *fuc)
 {
 	struct nvkm_subdev *subdev = &gr->base.engine.subdev;
 	struct nvkm_device *device = subdev->device;
+	const char *legacy_fwname = NULL;
 	const struct firmware *fw;
 	int ret;
 
 	ret = nvkm_firmware_get(device, fwname, &fw);
-	if (ret) {
+	/* firmware found, success! */
+	if (!ret) {
+		fuc->size = fw->size;
+		fuc->data = kmemdup(fw->data, fuc->size, GFP_KERNEL);
+		nvkm_firmware_put(fw);
+		return (fuc->data != NULL) ? 0 : -ENOMEM;
+	}
+
+	/* see if this firmware has a legacy path */
+	if (!strcmp(fwname, "fecs_inst"))
+		legacy_fwname = "fuc409c";
+	else if (!strcmp(fwname, "fecs_data"))
+		legacy_fwname = "fuc409d";
+	else if (!strcmp(fwname, "gpccs_inst"))
+		legacy_fwname = "fuc41ac";
+	else if (!strcmp(fwname, "gpccs_data"))
+		legacy_fwname = "fuc41ad";
+
+	/* nope, let's just return the error we got */
+	if (!legacy_fwname) {
 		nvkm_error(subdev, "failed to load %s\n", fwname);
 		return ret;
 	}
 
-	fuc->size = fw->size;
-	fuc->data = kmemdup(fw->data, fuc->size, GFP_KERNEL);
-	nvkm_firmware_put(fw);
-	return (fuc->data != NULL) ? 0 : -ENOMEM;
+	/* yes, try to load from the legacy path */
+	nvkm_debug(subdev, "%s: falling back to legacy path\n", fwname);
+	return gf100_gr_ctor_fw_legacy(gr, legacy_fwname, fuc);
 }
 
 int
-- 
2.10.0

On Wed, Nov 2, 2016 at 12:54 AM, Alexandre Courbot <acourbot at
nvidia.com> wrote:
> Look for firmware files using the legacy ("nouveau/nvxx_fucxxxx")
path
> if they cannot be found in the new, "official" path. User setups
were
> broken by the switch, which is bad.
>
> There are only 4 firmware files we may want to look up that way, so
> hardcode them into the lookup function. All new firmware files should
> use the standard "nvidia/<chip>/gr/" path.
>
> Fixes: 8539b37acef7 ("drm/nouveau/gr: use NVIDIA-provided external
firmwares")
> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
> ---
>  drm/nouveau/nvkm/engine/gr/gf100.c | 56
++++++++++++++++++++++++++++++++++----
>  1 file changed, 51 insertions(+), 5 deletions(-)
>
> diff --git a/drm/nouveau/nvkm/engine/gr/gf100.c
b/drm/nouveau/nvkm/engine/gr/gf100.c
> index 157919c788e6..9e65adbab21c 100644
> --- a/drm/nouveau/nvkm/engine/gr/gf100.c
> +++ b/drm/nouveau/nvkm/engine/gr/gf100.c
> @@ -1756,24 +1756,70 @@ gf100_gr_ = {
>  };
>
>  int
> +gf100_gr_ctor_fw_legacy(struct gf100_gr *gr, const char *fwname,
> +                       struct gf100_gr_fuc *fuc)
> +{
> +       struct nvkm_subdev *subdev = &gr->base.engine.subdev;
> +       struct nvkm_device *device = subdev->device;
> +       const struct firmware *fw;
> +       char f[32];
> +       int ret;
> +
> +       snprintf(f, sizeof(f), "nouveau/nv%02x_%s",
device->chipset, fwname);
> +       ret = request_firmware(&fw, f, device->dev);
> +       if (ret) {
> +               snprintf(f, sizeof(f), "nouveau/%s", fwname);
> +               ret = request_firmware(&fw, f, device->dev);
> +               if (ret) {
> +                       nvkm_error(subdev, "failed to load %s\n",
fwname);
> +                       return ret;
> +               }
> +       }
> +
> +       fuc->size = fw->size;
> +       fuc->data = kmemdup(fw->data, fuc->size, GFP_KERNEL);
> +       release_firmware(fw);
> +       return (fuc->data != NULL) ? 0 : -ENOMEM;
> +}
> +
> +int
>  gf100_gr_ctor_fw(struct gf100_gr *gr, const char *fwname,
>                  struct gf100_gr_fuc *fuc)
>  {
>         struct nvkm_subdev *subdev = &gr->base.engine.subdev;
>         struct nvkm_device *device = subdev->device;
> +       const char *legacy_fwname = NULL;
>         const struct firmware *fw;
>         int ret;
>
>         ret = nvkm_firmware_get(device, fwname, &fw);
> -       if (ret) {
> +       /* firmware found, success! */
> +       if (!ret) {
> +               fuc->size = fw->size;
> +               fuc->data = kmemdup(fw->data, fuc->size,
GFP_KERNEL);
> +               nvkm_firmware_put(fw);
> +               return (fuc->data != NULL) ? 0 : -ENOMEM;
> +       }
> +
> +       /* see if this firmware has a legacy path */
> +       if (!strcmp(fwname, "fecs_inst"))
> +               legacy_fwname = "fuc409c";
> +       else if (!strcmp(fwname, "fecs_data"))
> +               legacy_fwname = "fuc409d";
> +       else if (!strcmp(fwname, "gpccs_inst"))
> +               legacy_fwname = "fuc41ac";
> +       else if (!strcmp(fwname, "gpccs_data"))
> +               legacy_fwname = "fuc41ad";
As I mentioned on IRC, I find this strcmp thing a little jarring. It
should be pretty easy to just pass the legacy fwname into
gf100_gr_ctor_fw directly - there are only a handful of callers, and
most would just pass NULL in as the legacy fwname - only the ones in
gf100.c would pass the "old" names in.

Otherwise this looks great, thanks for taking care of it!
> +
> +       /* nope, let's just return the error we got */
> +       if (!legacy_fwname) {
>                 nvkm_error(subdev, "failed to load %s\n",
fwname);
>                 return ret;
>         }
>
> -       fuc->size = fw->size;
> -       fuc->data = kmemdup(fw->data, fuc->size, GFP_KERNEL);
> -       nvkm_firmware_put(fw);
> -       return (fuc->data != NULL) ? 0 : -ENOMEM;
> +       /* yes, try to load from the legacy path */
> +       nvkm_debug(subdev, "%s: falling back to legacy path\n",
fwname);
> +       return gf100_gr_ctor_fw_legacy(gr, legacy_fwname, fuc);
>  }
>
>  int
> --
> 2.10.0
>
> _______________________________________________
> Nouveau mailing list
> Nouveau at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/nouveau

On 11/02/2016 02:07 PM, Ilia Mirkin wrote:
> On Wed, Nov 2, 2016 at 12:54 AM, Alexandre Courbot <acourbot at
nvidia.com> wrote:
>> Look for firmware files using the legacy
("nouveau/nvxx_fucxxxx") path
>> if they cannot be found in the new, "official" path. User
setups were
>> broken by the switch, which is bad.
>>
>> There are only 4 firmware files we may want to look up that way, so
>> hardcode them into the lookup function. All new firmware files should
>> use the standard "nvidia/<chip>/gr/" path.
>>
>> Fixes: 8539b37acef7 ("drm/nouveau/gr: use NVIDIA-provided external
firmwares")
>> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
>> ---
>>  drm/nouveau/nvkm/engine/gr/gf100.c | 56
++++++++++++++++++++++++++++++++++----
>>  1 file changed, 51 insertions(+), 5 deletions(-)
>>
>> diff --git a/drm/nouveau/nvkm/engine/gr/gf100.c
b/drm/nouveau/nvkm/engine/gr/gf100.c
>> index 157919c788e6..9e65adbab21c 100644
>> --- a/drm/nouveau/nvkm/engine/gr/gf100.c
>> +++ b/drm/nouveau/nvkm/engine/gr/gf100.c
>> @@ -1756,24 +1756,70 @@ gf100_gr_ = {
>>  };
>>
>>  int
>> +gf100_gr_ctor_fw_legacy(struct gf100_gr *gr, const char *fwname,
>> +                       struct gf100_gr_fuc *fuc)
>> +{
>> +       struct nvkm_subdev *subdev = &gr->base.engine.subdev;
>> +       struct nvkm_device *device = subdev->device;
>> +       const struct firmware *fw;
>> +       char f[32];
>> +       int ret;
>> +
>> +       snprintf(f, sizeof(f), "nouveau/nv%02x_%s",
device->chipset, fwname);
>> +       ret = request_firmware(&fw, f, device->dev);
>> +       if (ret) {
>> +               snprintf(f, sizeof(f), "nouveau/%s", fwname);
>> +               ret = request_firmware(&fw, f, device->dev);
>> +               if (ret) {
>> +                       nvkm_error(subdev, "failed to load
%s\n", fwname);
>> +                       return ret;
>> +               }
>> +       }
>> +
>> +       fuc->size = fw->size;
>> +       fuc->data = kmemdup(fw->data, fuc->size, GFP_KERNEL);
>> +       release_firmware(fw);
>> +       return (fuc->data != NULL) ? 0 : -ENOMEM;
>> +}
>> +
>> +int
>>  gf100_gr_ctor_fw(struct gf100_gr *gr, const char *fwname,
>>                  struct gf100_gr_fuc *fuc)
>>  {
>>         struct nvkm_subdev *subdev = &gr->base.engine.subdev;
>>         struct nvkm_device *device = subdev->device;
>> +       const char *legacy_fwname = NULL;
>>         const struct firmware *fw;
>>         int ret;
>>
>>         ret = nvkm_firmware_get(device, fwname, &fw);
>> -       if (ret) {
>> +       /* firmware found, success! */
>> +       if (!ret) {
>> +               fuc->size = fw->size;
>> +               fuc->data = kmemdup(fw->data, fuc->size,
GFP_KERNEL);
>> +               nvkm_firmware_put(fw);
>> +               return (fuc->data != NULL) ? 0 : -ENOMEM;
>> +       }
>> +
>> +       /* see if this firmware has a legacy path */
>> +       if (!strcmp(fwname, "fecs_inst"))
>> +               legacy_fwname = "fuc409c";
>> +       else if (!strcmp(fwname, "fecs_data"))
>> +               legacy_fwname = "fuc409d";
>> +       else if (!strcmp(fwname, "gpccs_inst"))
>> +               legacy_fwname = "fuc41ac";
>> +       else if (!strcmp(fwname, "gpccs_data"))
>> +               legacy_fwname = "fuc41ad";
> 
> As I mentioned on IRC, I find this strcmp thing a little jarring. It
> should be pretty easy to just pass the legacy fwname into
> gf100_gr_ctor_fw directly - there are only a handful of callers, and
> most would just pass NULL in as the legacy fwname - only the ones in
> gf100.c would pass the "old" names in.
Yeah, that was the original approach actually. I switched to this for
the following reasons:

- We don't want to encourage using this legacy path, hence hiding it
from callers
- There are only 4 possible legacy files - it's ugly but still
manageable and contained in a single function

Of course, if the general consensus is that this is too ugly, it would
be trivial to turn it the way you suggested, so I don't feel too
strongly for one approach over the other.

Hi Alex,

On 2 November 2016 at 04:54, Alexandre Courbot <acourbot at nvidia.com>
wrote:
> +       /* see if this firmware has a legacy path */
> +       if (!strcmp(fwname, "fecs_inst"))
> +               legacy_fwname = "fuc409c";
> +       else if (!strcmp(fwname, "fecs_data"))
> +               legacy_fwname = "fuc409d";
> +       else if (!strcmp(fwname, "gpccs_inst"))
> +               legacy_fwname = "fuc41ac";
> +       else if (!strcmp(fwname, "gpccs_data"))
> +               legacy_fwname = "fuc41ad";
> +
Just an idea: If one's going for this route (and not Ilia's
suggestion) it's worth moving this in the legacy function.
As-is things look really weird ?

Thanks
Emil