| Message ID | 20200218171321.30990-7-robh@kernel.org |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | Removing Calxeda platform support | expand |
On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: > Cc: Will Deacon <will@kernel.org> > Cc: Robin Murphy <robin.murphy@arm.com> > Cc: Joerg Roedel <joro@8bytes.org> > Cc: iommu@lists.linux-foundation.org > Signed-off-by: Rob Herring <robh@kernel.org> > --- > Do not apply yet. Pleeeeease? ;) > drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- > 1 file changed, 43 deletions(-) Yes, I'm happy to get rid of this. Sadly, I don't think we can remove anything from 'struct arm_smmu_impl' because most implementations fall just short of perfect. Anyway, let me know when I can push the button and I'll queue this in the arm-smmu tree. Cheers, Will
On 18/02/2020 5:20 pm, Will Deacon wrote: > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: >> Cc: Will Deacon <will@kernel.org> >> Cc: Robin Murphy <robin.murphy@arm.com> >> Cc: Joerg Roedel <joro@8bytes.org> >> Cc: iommu@lists.linux-foundation.org >> Signed-off-by: Rob Herring <robh@kernel.org> >> --- >> Do not apply yet. > > Pleeeeease? ;) > >> drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- Presumably we also want to remove the definition of the option from binding too. >> 1 file changed, 43 deletions(-) > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove > anything from 'struct arm_smmu_impl' because most implementations fall > just short of perfect. Right, this served as the prototype for register access hooks, but we have at least one other known user for those. > Anyway, let me know when I can push the button and I'll queue this in > the arm-smmu tree. FWIW the quirk has proven useful in other circumstances too, but I imagine if we ever have to prototype an integration on VExpress-CA9 again, reverting this patch will hardly be the most unpleasant part :) Robin.
On Tue, Feb 18, 2020 at 11:20 AM Will Deacon <will@kernel.org> wrote: > > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: > > Cc: Will Deacon <will@kernel.org> > > Cc: Robin Murphy <robin.murphy@arm.com> > > Cc: Joerg Roedel <joro@8bytes.org> > > Cc: iommu@lists.linux-foundation.org > > Signed-off-by: Rob Herring <robh@kernel.org> > > --- > > Do not apply yet. > > Pleeeeease? ;) > > > drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- > > 1 file changed, 43 deletions(-) > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove > anything from 'struct arm_smmu_impl' because most implementations fall > just short of perfect. > > Anyway, let me know when I can push the button and I'll queue this in > the arm-smmu tree. Seems we're leaving the platform support for now, but I think we never actually enabled SMMU support. It's not in the dts either in mainline nor the version I have which should be close to what shipped in firmware. So as long as Andre agrees, this one is good to apply. Rob
On Fri, 28 Feb 2020 10:04:47 +0000 Will Deacon <will@kernel.org> wrote: Hi, > On Tue, Feb 25, 2020 at 04:01:54PM -0600, Rob Herring wrote: > > On Tue, Feb 18, 2020 at 11:20 AM Will Deacon <will@kernel.org> wrote: > > > > > > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: > > > > Cc: Will Deacon <will@kernel.org> > > > > Cc: Robin Murphy <robin.murphy@arm.com> > > > > Cc: Joerg Roedel <joro@8bytes.org> > > > > Cc: iommu@lists.linux-foundation.org > > > > Signed-off-by: Rob Herring <robh@kernel.org> > > > > --- > > > > Do not apply yet. > > > > > > Pleeeeease? ;) > > > > > > > drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- > > > > 1 file changed, 43 deletions(-) > > > > > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove > > > anything from 'struct arm_smmu_impl' because most implementations fall > > > just short of perfect. > > > > > > Anyway, let me know when I can push the button and I'll queue this in > > > the arm-smmu tree. > > > > Seems we're leaving the platform support for now, but I think we never > > actually enabled SMMU support. It's not in the dts either in mainline > > nor the version I have which should be close to what shipped in > > firmware. So as long as Andre agrees, this one is good to apply. > > Andre? Can I queue this one for 5.7, please? I was wondering how much of a pain it is to keep it in? AFAICS there are other users of the "impl" indirection. If those goes away, I would be happy to let Calxeda go. But Eric had the magic DT nodes to get the SMMU working, and I used that before, with updating the DT either on flash or dynamically via U-Boot. So I don't know exactly *how* desperate you are with removing this, or if there are other reasons than "negative diffstat", but if possible I would like to keep it in. Cheers, Andre.
On Fri, 28 Feb 2020 10:50:25 +0000 Will Deacon <will@kernel.org> wrote: > On Fri, Feb 28, 2020 at 10:25:56AM +0000, Andre Przywara wrote: > > On Fri, 28 Feb 2020 10:04:47 +0000 > > Will Deacon <will@kernel.org> wrote: > > > > Hi, > > > > > On Tue, Feb 25, 2020 at 04:01:54PM -0600, Rob Herring wrote: > > > > On Tue, Feb 18, 2020 at 11:20 AM Will Deacon <will@kernel.org> wrote: > > > > > > > > > > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: > > > > > > Cc: Will Deacon <will@kernel.org> > > > > > > Cc: Robin Murphy <robin.murphy@arm.com> > > > > > > Cc: Joerg Roedel <joro@8bytes.org> > > > > > > Cc: iommu@lists.linux-foundation.org > > > > > > Signed-off-by: Rob Herring <robh@kernel.org> > > > > > > --- > > > > > > Do not apply yet. > > > > > > > > > > Pleeeeease? ;) > > > > > > > > > > > drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- > > > > > > 1 file changed, 43 deletions(-) > > > > > > > > > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove > > > > > anything from 'struct arm_smmu_impl' because most implementations fall > > > > > just short of perfect. > > > > > > > > > > Anyway, let me know when I can push the button and I'll queue this in > > > > > the arm-smmu tree. > > > > > > > > Seems we're leaving the platform support for now, but I think we never > > > > actually enabled SMMU support. It's not in the dts either in mainline > > > > nor the version I have which should be close to what shipped in > > > > firmware. So as long as Andre agrees, this one is good to apply. > > > > > > Andre? Can I queue this one for 5.7, please? > > > > I was wondering how much of a pain it is to keep it in? AFAICS there are > > other users of the "impl" indirection. If those goes away, I would be > > happy to let Calxeda go. > > The impl stuff is new, so we'll keep it around. The concern is more about > testing (see below). > > > But Eric had the magic DT nodes to get the SMMU working, and I used that > > before, with updating the DT either on flash or dynamically via U-Boot. > > What did you actually use the SMMU for, though? The > 'arm_iommu_create_mapping()' interface isn't widely used and, given that > highbank doesn't support KVM, the use-cases for VFIO are pretty limited > too. AFAIK Highbank doesn't have the SMMU, probably mostly for that reason. I have a DT snippet for Midway, and that puts the MMIO base at ~36GB, which is not possible on Highbank. So I think that the quirk is really meant and needed for Midway. > > So I don't know exactly *how* desperate you are with removing this, or if > > there are other reasons than "negative diffstat", but if possible I would > > like to keep it in. > > It's more that we *do* make quite a lot of changes to the arm-smmu driver > and it's never tested with this quirk. If you're stepping up to run smmu > tests on my queue for each release on highbank, then great, but otherwise > I'd rather not carry the code for fun. The change in diffstat is minimal > (we're going to need to hooks for nvidia, who broke things in a different > way). I am about to set up some more sophisticated testing, and will include some SMMU bits in it. Cheers, Andre. > Also, since the hooks aren't going away, if you /do/ end up using the SMMU > in future, then we could re-add the driver quirk without any fuss. > > Will
On Fri, 28 Feb 2020 13:56:46 +0000 Will Deacon <will@kernel.org> wrote: > On Fri, Feb 28, 2020 at 01:42:54PM +0000, Andre Przywara wrote: > > On Fri, 28 Feb 2020 10:50:25 +0000 > > Will Deacon <will@kernel.org> wrote: > > > On Fri, Feb 28, 2020 at 10:25:56AM +0000, Andre Przywara wrote: > > > > > On Tue, Feb 25, 2020 at 04:01:54PM -0600, Rob Herring wrote: > > > > > > Seems we're leaving the platform support for now, but I think we never > > > > > > actually enabled SMMU support. It's not in the dts either in mainline > > > > > > nor the version I have which should be close to what shipped in > > > > > > firmware. So as long as Andre agrees, this one is good to apply. > > > > > > > > > > Andre? Can I queue this one for 5.7, please? > > > > > > > > I was wondering how much of a pain it is to keep it in? AFAICS there are > > > > other users of the "impl" indirection. If those goes away, I would be > > > > happy to let Calxeda go. > > > > > > The impl stuff is new, so we'll keep it around. The concern is more about > > > testing (see below). > > > > > > > But Eric had the magic DT nodes to get the SMMU working, and I used that > > > > before, with updating the DT either on flash or dynamically via U-Boot. > > > > > > What did you actually use the SMMU for, though? The > > > 'arm_iommu_create_mapping()' interface isn't widely used and, given that > > > highbank doesn't support KVM, the use-cases for VFIO are pretty limited > > > too. > > > > AFAIK Highbank doesn't have the SMMU, probably mostly for that reason. > > I have a DT snippet for Midway, and that puts the MMIO base at ~36GB, which is not possible on Highbank. > > So I think that the quirk is really meant and needed for Midway. > > Sorry, but I don't follow your reasoning here. The MMIO base has nothing > to do with the quirk, It hasn't, but Highbank has no LPAE, so couldn't possible have a device at such an address. And this is the only MMIO address I know of. > although doing some digging it looks like your > conclusion about this applying to Midway (ecx-2000?) is correct: > > http://lists.infradead.org/pipermail/linux-arm-kernel/2014-January/226095.html Right, thanks for that find. Yes, Midway is the codename for the ECX-2000 SoC product. Cheers, Andre > > > > So I don't know exactly *how* desperate you are with removing this, or if > > > > there are other reasons than "negative diffstat", but if possible I would > > > > like to keep it in. > > > > > > It's more that we *do* make quite a lot of changes to the arm-smmu driver > > > and it's never tested with this quirk. If you're stepping up to run smmu > > > tests on my queue for each release on highbank, then great, but otherwise > > > I'd rather not carry the code for fun. The change in diffstat is minimal > > > (we're going to need to hooks for nvidia, who broke things in a different > > > way). > > > > I am about to set up some more sophisticated testing, and will include > > some SMMU bits in it. > > Yes, please. > > Will
diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c index 74d97a886e93..a3be8712d27f 100644 --- a/drivers/iommu/arm-smmu-impl.c +++ b/drivers/iommu/arm-smmu-impl.c @@ -9,45 +9,6 @@ #include "arm-smmu.h" - -static int arm_smmu_gr0_ns(int offset) -{ - switch(offset) { - case ARM_SMMU_GR0_sCR0: - case ARM_SMMU_GR0_sACR: - case ARM_SMMU_GR0_sGFSR: - case ARM_SMMU_GR0_sGFSYNR0: - case ARM_SMMU_GR0_sGFSYNR1: - case ARM_SMMU_GR0_sGFSYNR2: - return offset + 0x400; - default: - return offset; - } -} - -static u32 arm_smmu_read_ns(struct arm_smmu_device *smmu, int page, - int offset) -{ - if (page == ARM_SMMU_GR0) - offset = arm_smmu_gr0_ns(offset); - return readl_relaxed(arm_smmu_page(smmu, page) + offset); -} - -static void arm_smmu_write_ns(struct arm_smmu_device *smmu, int page, - int offset, u32 val) -{ - if (page == ARM_SMMU_GR0) - offset = arm_smmu_gr0_ns(offset); - writel_relaxed(val, arm_smmu_page(smmu, page) + offset); -} - -/* Since we don't care for sGFAR, we can do without 64-bit accessors */ -static const struct arm_smmu_impl calxeda_impl = { - .read_reg = arm_smmu_read_ns, - .write_reg = arm_smmu_write_ns, -}; - - struct cavium_smmu { struct arm_smmu_device smmu; u32 id_base; @@ -166,10 +127,6 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) break; } - if (of_property_read_bool(smmu->dev->of_node, - "calxeda,smmu-secure-config-access")) - smmu->impl = &calxeda_impl; - if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm845-smmu-500")) return qcom_smmu_impl_init(smmu);
Cc: Will Deacon <will@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: iommu@lists.linux-foundation.org Signed-off-by: Rob Herring <robh@kernel.org> --- Do not apply yet. drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- 1 file changed, 43 deletions(-) -- 2.20.1