Re: [PATCH v6 8/9] iommu/arm-smmu: Get associated RMR info and install bypass SMR
On Fri, Jul 16, 2021 at 3:52 PM Steven Price wrote: > > On 16/07/2021 09:34, Shameer Kolothum wrote: > > From: Jon Nettleton > > > > Check if there is any RMR info associated with the devices behind > > the SMMU and if any, install bypass SMRs for them. This is to > > keep any ongoing traffic associated with these devices alive > > when we enable/reset SMMU during probe(). > > > > Signed-off-by: Jon Nettleton > > Signed-off-by: Steven Price > > Signed-off-by: Shameer Kolothum > > --- > > drivers/iommu/arm/arm-smmu/arm-smmu.c | 48 +++ > > 1 file changed, 48 insertions(+) > > > > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c > > b/drivers/iommu/arm/arm-smmu/arm-smmu.c > > index f22dbeb1e510..e9fb3d962a86 100644 > > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c > > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c > > @@ -2063,6 +2063,50 @@ err_reset_platform_ops: __maybe_unused; > > return err; > > } > > > > +static void arm_smmu_rmr_install_bypass_smr(struct arm_smmu_device *smmu) > > +{ > > + struct list_head rmr_list; > > + struct iommu_resv_region *e; > > + int i, cnt = 0; > > + u32 reg; > > + > > + INIT_LIST_HEAD(&rmr_list); > > + if (iommu_dma_get_rmrs(dev_fwnode(smmu->dev), &rmr_list)) > > + return; > > + > > + /* > > + * Rather than trying to look at existing mappings that > > + * are setup by the firmware and then invalidate the ones > > + * that do no have matching RMR entries, just disable the > > + * SMMU until it gets enabled again in the reset routine. > > + */ > > + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sCR0); > > + reg &= ~ARM_SMMU_sCR0_CLIENTPD; > > This looks backwards, the spec states: > > Client Port Disable. The possible values of this bit are: > 0 - Each SMMU client access is subject to SMMU translation, access > control, and attribute generation. > 1 - Each SMMU client access bypasses SMMU translation, access control, > and attribute generation. > This bit resets to 1. > > And indeed with the current code if sCR0_USFCFG was set when > sCR0_CLIENTPD is cleared then I get a blank screen until the smmu is reset. > > So I believe this should be ORing in the value, i.e. > > reg |= ARM_SMMU_sCR0_CLIENTPD; > > And in my testing that works fine even if sCR0_USFCFG is set. Sorry that is my bad. It was a hurried and sloppy copy paste on my part. Thanks for catching it -Jon > > Steve > > > + arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sCR0, reg); > > + > > + list_for_each_entry(e, &rmr_list, list) { > > + u32 sid = e->fw_data.rmr.sid; > > + > > + i = arm_smmu_find_sme(smmu, sid, ~0); > > + if (i < 0) > > + continue; > > + if (smmu->s2crs[i].count == 0) { > > + smmu->smrs[i].id = sid; > > + smmu->smrs[i].mask = 0; > > + smmu->smrs[i].valid = true; > > + } > > + smmu->s2crs[i].count++; > > + smmu->s2crs[i].type = S2CR_TYPE_BYPASS; > > + smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT; > > + > > + cnt++; > > + } > > + > > + dev_notice(smmu->dev, "\tpreserved %d boot mapping%s\n", cnt, > > +cnt == 1 ? "" : "s"); > > + iommu_dma_put_rmrs(dev_fwnode(smmu->dev), &rmr_list); > > +} > > + > > static int arm_smmu_device_probe(struct platform_device *pdev) > > { > > struct resource *res; > > @@ -2189,6 +2233,10 @@ static int arm_smmu_device_probe(struct > > platform_device *pdev) > > } > > > > platform_set_drvdata(pdev, smmu); > > + > > + /* Check for RMRs and install bypass SMRs if any */ > > + arm_smmu_rmr_install_bypass_smr(smmu); > > + > > arm_smmu_device_reset(smmu); > > arm_smmu_test_smr_masks(smmu); > > > > > ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v6 8/9] iommu/arm-smmu: Get associated RMR info and install bypass SMR
On 16/07/2021 09:34, Shameer Kolothum wrote: > From: Jon Nettleton > > Check if there is any RMR info associated with the devices behind > the SMMU and if any, install bypass SMRs for them. This is to > keep any ongoing traffic associated with these devices alive > when we enable/reset SMMU during probe(). > > Signed-off-by: Jon Nettleton > Signed-off-by: Steven Price > Signed-off-by: Shameer Kolothum > --- > drivers/iommu/arm/arm-smmu/arm-smmu.c | 48 +++ > 1 file changed, 48 insertions(+) > > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c > b/drivers/iommu/arm/arm-smmu/arm-smmu.c > index f22dbeb1e510..e9fb3d962a86 100644 > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c > @@ -2063,6 +2063,50 @@ err_reset_platform_ops: __maybe_unused; > return err; > } > > +static void arm_smmu_rmr_install_bypass_smr(struct arm_smmu_device *smmu) > +{ > + struct list_head rmr_list; > + struct iommu_resv_region *e; > + int i, cnt = 0; > + u32 reg; > + > + INIT_LIST_HEAD(&rmr_list); > + if (iommu_dma_get_rmrs(dev_fwnode(smmu->dev), &rmr_list)) > + return; > + > + /* > + * Rather than trying to look at existing mappings that > + * are setup by the firmware and then invalidate the ones > + * that do no have matching RMR entries, just disable the > + * SMMU until it gets enabled again in the reset routine. > + */ > + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sCR0); > + reg &= ~ARM_SMMU_sCR0_CLIENTPD; This looks backwards, the spec states: Client Port Disable. The possible values of this bit are: 0 - Each SMMU client access is subject to SMMU translation, access control, and attribute generation. 1 - Each SMMU client access bypasses SMMU translation, access control, and attribute generation. This bit resets to 1. And indeed with the current code if sCR0_USFCFG was set when sCR0_CLIENTPD is cleared then I get a blank screen until the smmu is reset. So I believe this should be ORing in the value, i.e. reg |= ARM_SMMU_sCR0_CLIENTPD; And in my testing that works fine even if sCR0_USFCFG is set. Steve > + arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sCR0, reg); > + > + list_for_each_entry(e, &rmr_list, list) { > + u32 sid = e->fw_data.rmr.sid; > + > + i = arm_smmu_find_sme(smmu, sid, ~0); > + if (i < 0) > + continue; > + if (smmu->s2crs[i].count == 0) { > + smmu->smrs[i].id = sid; > + smmu->smrs[i].mask = 0; > + smmu->smrs[i].valid = true; > + } > + smmu->s2crs[i].count++; > + smmu->s2crs[i].type = S2CR_TYPE_BYPASS; > + smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT; > + > + cnt++; > + } > + > + dev_notice(smmu->dev, "\tpreserved %d boot mapping%s\n", cnt, > +cnt == 1 ? "" : "s"); > + iommu_dma_put_rmrs(dev_fwnode(smmu->dev), &rmr_list); > +} > + > static int arm_smmu_device_probe(struct platform_device *pdev) > { > struct resource *res; > @@ -2189,6 +2233,10 @@ static int arm_smmu_device_probe(struct > platform_device *pdev) > } > > platform_set_drvdata(pdev, smmu); > + > + /* Check for RMRs and install bypass SMRs if any */ > + arm_smmu_rmr_install_bypass_smr(smmu); > + > arm_smmu_device_reset(smmu); > arm_smmu_test_smr_masks(smmu); > > ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
[PATCH v6 8/9] iommu/arm-smmu: Get associated RMR info and install bypass SMR
From: Jon Nettleton Check if there is any RMR info associated with the devices behind the SMMU and if any, install bypass SMRs for them. This is to keep any ongoing traffic associated with these devices alive when we enable/reset SMMU during probe(). Signed-off-by: Jon Nettleton Signed-off-by: Steven Price Signed-off-by: Shameer Kolothum --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 48 +++ 1 file changed, 48 insertions(+) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index f22dbeb1e510..e9fb3d962a86 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -2063,6 +2063,50 @@ err_reset_platform_ops: __maybe_unused; return err; } +static void arm_smmu_rmr_install_bypass_smr(struct arm_smmu_device *smmu) +{ + struct list_head rmr_list; + struct iommu_resv_region *e; + int i, cnt = 0; + u32 reg; + + INIT_LIST_HEAD(&rmr_list); + if (iommu_dma_get_rmrs(dev_fwnode(smmu->dev), &rmr_list)) + return; + + /* +* Rather than trying to look at existing mappings that +* are setup by the firmware and then invalidate the ones +* that do no have matching RMR entries, just disable the +* SMMU until it gets enabled again in the reset routine. +*/ + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sCR0); + reg &= ~ARM_SMMU_sCR0_CLIENTPD; + arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sCR0, reg); + + list_for_each_entry(e, &rmr_list, list) { + u32 sid = e->fw_data.rmr.sid; + + i = arm_smmu_find_sme(smmu, sid, ~0); + if (i < 0) + continue; + if (smmu->s2crs[i].count == 0) { + smmu->smrs[i].id = sid; + smmu->smrs[i].mask = 0; + smmu->smrs[i].valid = true; + } + smmu->s2crs[i].count++; + smmu->s2crs[i].type = S2CR_TYPE_BYPASS; + smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT; + + cnt++; + } + + dev_notice(smmu->dev, "\tpreserved %d boot mapping%s\n", cnt, + cnt == 1 ? "" : "s"); + iommu_dma_put_rmrs(dev_fwnode(smmu->dev), &rmr_list); +} + static int arm_smmu_device_probe(struct platform_device *pdev) { struct resource *res; @@ -2189,6 +2233,10 @@ static int arm_smmu_device_probe(struct platform_device *pdev) } platform_set_drvdata(pdev, smmu); + + /* Check for RMRs and install bypass SMRs if any */ + arm_smmu_rmr_install_bypass_smr(smmu); + arm_smmu_device_reset(smmu); arm_smmu_test_smr_masks(smmu); -- 2.17.1 ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu