| Message ID | 20171129152001.29669-1-msrb@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am 29.11.2017 um 16:20 schrieb Michal Srb: > The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 > and is called unconditionally. However, not all drivers were updated to set it. > > Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. > > Signed-off-by: Michal Srb <msrb@suse.com> NAK, when we have drivers missing this we should set this in the driver and not add the workaround here. Which driver is missing this? I thought I fixed all of them. Regards, Christian. > --- > drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c > index c8ebb757e36b..e25a99bc519d 100644 > --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c > +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c > @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > if (bo->mem.bus.is_iomem) { > /* Iomem should not be marked encrypted */ > cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); > - pfn = bdev->driver->io_mem_pfn(bo, page_offset); > + if (bdev->driver->io_mem_pfn) > + pfn = bdev->driver->io_mem_pfn(bo, page_offset); > + else > + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); > } else { > page = ttm->pages[page_offset]; > if (unlikely(!page && i == 0)) {
On Wednesday 29th November 2017 16:24:21 CET Christian König wrote: > Am 29.11.2017 um 16:20 schrieb Michal Srb: > > The io_mem_pfn field was added in commit > > ea642c3216cb2a60d1c0e760ae47ee85c9c16447 and is called unconditionally. > > However, not all drivers were updated to set it. > > > > Use the ttm_bo_default_io_mem_pfn function if a driver did not set its > > own. > > > > Signed-off-by: Michal Srb <msrb@suse.com> > > NAK, when we have drivers missing this we should set this in the driver > and not add the workaround here. > > Which driver is missing this? I thought I fixed all of them. The one where I ran into the problem is hibmc. I've sent patch fixing it, but reportedly there is more drivers with the same issue, so this fix was suggested instead: On Wednesday 29th November 2017 15:47:30 CET Sean Paul wrote: > Instead of just doing the same cargo cult in this driver, lets just call the > default function when io_mem_pfn is NULL. Looks like 9 other drivers are > affected as well. > Sean Michal
On Wed, Nov 29, 2017 at 04:24:21PM +0100, Christian König wrote: > Am 29.11.2017 um 16:20 schrieb Michal Srb: > > The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 > > and is called unconditionally. However, not all drivers were updated to set it. > > > > Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. > > > > Signed-off-by: Michal Srb <msrb@suse.com> > > NAK, when we have drivers missing this we should set this in the driver and > not add the workaround here. Why? What's the benefit in adding the same hook in 10 drivers (I was hoping Michal would also remove the token .io_mem_pfn = ttm_bo_default_io_mem_pfn from those as well)? Sean > > Which driver is missing this? I thought I fixed all of them. > > Regards, > Christian. > > > --- > > drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > index c8ebb757e36b..e25a99bc519d 100644 > > --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c > > +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > > if (bo->mem.bus.is_iomem) { > > /* Iomem should not be marked encrypted */ > > cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); > > - pfn = bdev->driver->io_mem_pfn(bo, page_offset); > > + if (bdev->driver->io_mem_pfn) > > + pfn = bdev->driver->io_mem_pfn(bo, page_offset); > > + else > > + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); > > } else { > > page = ttm->pages[page_offset]; > > if (unlikely(!page && i == 0)) { > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Am 29.11.2017 um 16:36 schrieb Sean Paul: > On Wed, Nov 29, 2017 at 04:24:21PM +0100, Christian König wrote: >> Am 29.11.2017 um 16:20 schrieb Michal Srb: >>> The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 >>> and is called unconditionally. However, not all drivers were updated to set it. >>> >>> Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. >>> >>> Signed-off-by: Michal Srb <msrb@suse.com> >> NAK, when we have drivers missing this we should set this in the driver and >> not add the workaround here. > Why? What's the benefit in adding the same hook in 10 drivers (I was hoping > Michal would also remove the token .io_mem_pfn = ttm_bo_default_io_mem_pfn from > those as well)? Not have this extra check in common TTM code? That is seriously bad coding style. We have tons of fallbacks like this and I unfortunately even created new one without realizing that this is a problem. But this really clutters the TTM code and makes it harder to understand. Christian. > > Sean > >> Which driver is missing this? I thought I fixed all of them. >> >> Regards, >> Christian. >> >>> --- >>> drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- >>> 1 file changed, 4 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> index c8ebb757e36b..e25a99bc519d 100644 >>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c >>> @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>> if (bo->mem.bus.is_iomem) { >>> /* Iomem should not be marked encrypted */ >>> cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); >>> - pfn = bdev->driver->io_mem_pfn(bo, page_offset); >>> + if (bdev->driver->io_mem_pfn) >>> + pfn = bdev->driver->io_mem_pfn(bo, page_offset); >>> + else >>> + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); >>> } else { >>> page = ttm->pages[page_offset]; >>> if (unlikely(!page && i == 0)) { >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Wed, Nov 29, 2017 at 04:40:18PM +0100, Christian König wrote: > Am 29.11.2017 um 16:36 schrieb Sean Paul: > > On Wed, Nov 29, 2017 at 04:24:21PM +0100, Christian König wrote: > > > Am 29.11.2017 um 16:20 schrieb Michal Srb: > > > > The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 > > > > and is called unconditionally. However, not all drivers were updated to set it. > > > > > > > > Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. > > > > > > > > Signed-off-by: Michal Srb <msrb@suse.com> > > > NAK, when we have drivers missing this we should set this in the driver and > > > not add the workaround here. > > Why? What's the benefit in adding the same hook in 10 drivers (I was hoping > > Michal would also remove the token .io_mem_pfn = ttm_bo_default_io_mem_pfn from > > those as well)? > > Not have this extra check in common TTM code? That is seriously bad coding > style. > [citation neeeded] I'd argue it's bad form to require everyone add a copypasta hook to their driver everytime an unrelated driver needs more control than the default gives :-) I think your point would hold if we were talking about a couple of drivers, but once you scale to 10+, it's no longer a trivial amount of code. If the null check is too distracting, you could always pull it out into an inline. Sean > We have tons of fallbacks like this and I unfortunately even created new one > without realizing that this is a problem. > > But this really clutters the TTM code and makes it harder to understand. > > Christian. > > > > > Sean > > > > > Which driver is missing this? I thought I fixed all of them. > > > > > > Regards, > > > Christian. > > > > > > > --- > > > > drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- > > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > index c8ebb757e36b..e25a99bc519d 100644 > > > > --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > > > > if (bo->mem.bus.is_iomem) { > > > > /* Iomem should not be marked encrypted */ > > > > cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); > > > > - pfn = bdev->driver->io_mem_pfn(bo, page_offset); > > > > + if (bdev->driver->io_mem_pfn) > > > > + pfn = bdev->driver->io_mem_pfn(bo, page_offset); > > > > + else > > > > + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); > > > > } else { > > > > page = ttm->pages[page_offset]; > > > > if (unlikely(!page && i == 0)) { > > > _______________________________________________ > > > dri-devel mailing list > > > dri-devel@lists.freedesktop.org > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel >
Am 29.11.2017 um 16:44 schrieb Sean Paul: > On Wed, Nov 29, 2017 at 04:40:18PM +0100, Christian König wrote: >> Am 29.11.2017 um 16:36 schrieb Sean Paul: >>> On Wed, Nov 29, 2017 at 04:24:21PM +0100, Christian König wrote: >>>> Am 29.11.2017 um 16:20 schrieb Michal Srb: >>>>> The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 >>>>> and is called unconditionally. However, not all drivers were updated to set it. >>>>> >>>>> Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. >>>>> >>>>> Signed-off-by: Michal Srb <msrb@suse.com> >>>> NAK, when we have drivers missing this we should set this in the driver and >>>> not add the workaround here. >>> Why? What's the benefit in adding the same hook in 10 drivers (I was hoping >>> Michal would also remove the token .io_mem_pfn = ttm_bo_default_io_mem_pfn from >>> those as well)? >> Not have this extra check in common TTM code? That is seriously bad coding >> style. >> > [citation neeeded] > > I'd argue it's bad form to require everyone add a copypasta hook to their driver > everytime an unrelated driver needs more control than the default gives :-) Well that is another design problem of TTM that it works like a middle layer instead of a tool. But I'm seriously not going to fix this anytime soon. > I think your point would hold if we were talking about a couple of drivers, but > once you scale to 10+, it's no longer a trivial amount of code. If the null check > is too distracting, you could always pull it out into an inline. Yeah, that is one possibility that would work for me as well. TTM has patterns like the following: First occasion: if (a_is_available) do_a(); else do_b(); Same code a bit lower: if (a_is_available) do_a() /* Else is missing here */ I'm seriously favoring updating a dozen drivers just to avoid more of this. If you want to fix that with adding wrapper functions to call the driver callback and give a consistent operation when the callback isn't available then I'm perfectly fine with that as well. Patches are always welcome. Christian. > > Sean > > >> We have tons of fallbacks like this and I unfortunately even created new one >> without realizing that this is a problem. >> >> But this really clutters the TTM code and makes it harder to understand. >> >> Christian. >> >>> Sean >>> >>>> Which driver is missing this? I thought I fixed all of them. >>>> >>>> Regards, >>>> Christian. >>>> >>>>> --- >>>>> drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- >>>>> 1 file changed, 4 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c >>>>> index c8ebb757e36b..e25a99bc519d 100644 >>>>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c >>>>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c >>>>> @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) >>>>> if (bo->mem.bus.is_iomem) { >>>>> /* Iomem should not be marked encrypted */ >>>>> cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); >>>>> - pfn = bdev->driver->io_mem_pfn(bo, page_offset); >>>>> + if (bdev->driver->io_mem_pfn) >>>>> + pfn = bdev->driver->io_mem_pfn(bo, page_offset); >>>>> + else >>>>> + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); >>>>> } else { >>>>> page = ttm->pages[page_offset]; >>>>> if (unlikely(!page && i == 0)) { >>>> _______________________________________________ >>>> dri-devel mailing list >>>> dri-devel@lists.freedesktop.org >>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Wed, Nov 29, 2017 at 04:59:29PM +0100, Christian König wrote: > Am 29.11.2017 um 16:44 schrieb Sean Paul: > > On Wed, Nov 29, 2017 at 04:40:18PM +0100, Christian König wrote: > > > Am 29.11.2017 um 16:36 schrieb Sean Paul: > > > > On Wed, Nov 29, 2017 at 04:24:21PM +0100, Christian König wrote: > > > > > Am 29.11.2017 um 16:20 schrieb Michal Srb: > > > > > > The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 > > > > > > and is called unconditionally. However, not all drivers were updated to set it. > > > > > > > > > > > > Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. > > > > > > > > > > > > Signed-off-by: Michal Srb <msrb@suse.com> > > > > > NAK, when we have drivers missing this we should set this in the driver and > > > > > not add the workaround here. > > > > Why? What's the benefit in adding the same hook in 10 drivers (I was hoping > > > > Michal would also remove the token .io_mem_pfn = ttm_bo_default_io_mem_pfn from > > > > those as well)? > > > Not have this extra check in common TTM code? That is seriously bad coding > > > style. > > > > > [citation neeeded] > > > > I'd argue it's bad form to require everyone add a copypasta hook to their driver > > everytime an unrelated driver needs more control than the default gives :-) > > Well that is another design problem of TTM that it works like a middle layer > instead of a tool. But I'm seriously not going to fix this anytime soon. > > > I think your point would hold if we were talking about a couple of drivers, but > > once you scale to 10+, it's no longer a trivial amount of code. If the null check > > is too distracting, you could always pull it out into an inline. > Yeah, that is one possibility that would work for me as well. > > TTM has patterns like the following: > > First occasion: > if (a_is_available) > do_a(); > else > do_b(); > > Same code a bit lower: > if (a_is_available) > do_a() > /* Else is missing here */ > > I'm seriously favoring updating a dozen drivers just to avoid more of this. > > If you want to fix that with adding wrapper functions to call the driver > callback and give a consistent operation when the callback isn't available > then I'm perfectly fine with that as well. Patches are always welcome. Yeah, that's what I was asking Michal for. I'd like a patch series where: [0/N] adds the inline to call the default if io_mem_pfn is NULL [1..N-1/N] remove all .io_mem_pfn = ttm_bo_default_io_mem_pfn from drivers [N/N] unexport ttm_bo_default_io_mem_pfn and make it static Sean > > Christian. > > > > > Sean > > > > > > > We have tons of fallbacks like this and I unfortunately even created new one > > > without realizing that this is a problem. > > > > > > But this really clutters the TTM code and makes it harder to understand. > > > > > > Christian. > > > > > > > Sean > > > > > > > > > Which driver is missing this? I thought I fixed all of them. > > > > > > > > > > Regards, > > > > > Christian. > > > > > > > > > > > --- > > > > > > drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- > > > > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > > > index c8ebb757e36b..e25a99bc519d 100644 > > > > > > --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > > > @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) > > > > > > if (bo->mem.bus.is_iomem) { > > > > > > /* Iomem should not be marked encrypted */ > > > > > > cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); > > > > > > - pfn = bdev->driver->io_mem_pfn(bo, page_offset); > > > > > > + if (bdev->driver->io_mem_pfn) > > > > > > + pfn = bdev->driver->io_mem_pfn(bo, page_offset); > > > > > > + else > > > > > > + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); > > > > > > } else { > > > > > > page = ttm->pages[page_offset]; > > > > > > if (unlikely(!page && i == 0)) { > > > > > _______________________________________________ > > > > > dri-devel mailing list > > > > > dri-devel@lists.freedesktop.org > > > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel >
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index c8ebb757e36b..e25a99bc519d 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf) if (bo->mem.bus.is_iomem) { /* Iomem should not be marked encrypted */ cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); - pfn = bdev->driver->io_mem_pfn(bo, page_offset); + if (bdev->driver->io_mem_pfn) + pfn = bdev->driver->io_mem_pfn(bo, page_offset); + else + pfn = ttm_bo_default_io_mem_pfn(bo, page_offset); } else { page = ttm->pages[page_offset]; if (unlikely(!page && i == 0)) {
The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447 and is called unconditionally. However, not all drivers were updated to set it. Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own. Signed-off-by: Michal Srb <msrb@suse.com> --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)