| Message ID | 1595390431-24805-2-git-send-email-brian.woods@xilinx.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Generic SMMU Bindings | expand |
On Tue, 21 Jul 2020, Brian Woods wrote: > Modify the smmu driver so that it uses the iommu_fwspec helper > functions. This means both ARM IOMMU drivers will both use the > iommu_fwspec helper functions. > > Signed-off-by: Brian Woods <brian.woods@xilinx.com> [...] > @@ -1924,14 +1924,21 @@ static int arm_smmu_add_device(struct device *dev) > ret = -ENOMEM; > goto out_put_group; > } > + cfg->fwspec = kzalloc(sizeof(struct iommu_fwspec), GFP_KERNEL); > + if (!cfg->fwspec) { > + kfree(cfg); > + ret = -ENOMEM; > + goto out_put_group; > + } > + iommu_fwspec_init(dev, smmu->dev); Normally the fwspec structure is initialized in xen/drivers/passthrough/device_tree.c:iommu_add_dt_device. However here we are trying to use it with the legacy bindings, that of course don't initialize in iommu_add_dt_device because they are different. So I imagine this is the reason why we have to initialize iommu_fwspec here indepdendently from iommu_add_dt_device. However, why are we allocating the struct iommu_fwspec twice? We are calling kzalloc, then iommu_fwspec_init is calling xzalloc. Similarly, we are storing the pointer to struct iommu_fwspec in cfg->fwspec but actually there is already a pointer to struct iommu_fwspec in struct device (the one set by dev_iommu_fwspec_set.) Do we actually need both?
On Wed, Jul 22, 2020 at 09:47:43AM -0700, Stefano Stabellini wrote: > On Tue, 21 Jul 2020, Brian Woods wrote: > > Modify the smmu driver so that it uses the iommu_fwspec helper > > functions. This means both ARM IOMMU drivers will both use the > > iommu_fwspec helper functions. > > > > Signed-off-by: Brian Woods <brian.woods@xilinx.com> > > [...] > > > @@ -1924,14 +1924,21 @@ static int arm_smmu_add_device(struct device *dev) > > ret = -ENOMEM; > > goto out_put_group; > > } > > + cfg->fwspec = kzalloc(sizeof(struct iommu_fwspec), GFP_KERNEL); > > + if (!cfg->fwspec) { > > + kfree(cfg); > > + ret = -ENOMEM; > > + goto out_put_group; > > + } > > + iommu_fwspec_init(dev, smmu->dev); > > Normally the fwspec structure is initialized in > xen/drivers/passthrough/device_tree.c:iommu_add_dt_device. However here > we are trying to use it with the legacy bindings, that of course don't > initialize in iommu_add_dt_device because they are different. > > So I imagine this is the reason why we have to initialize iommu_fwspec here > indepdendently from iommu_add_dt_device. > > However, why are we allocating the struct iommu_fwspec twice? > > We are calling kzalloc, then iommu_fwspec_init is calling xzalloc. > > Similarly, we are storing the pointer to struct iommu_fwspec in > cfg->fwspec but actually there is already a pointer to struct > iommu_fwspec in struct device (the one set by dev_iommu_fwspec_set.) > > Do we actually need both? Sorry for taking so long. Hrm, I've been looking for why I created two fwspecs and I'm not sure why... It's pretty late, but later this morning I'll try some things and try and remove it. Brian
Hi Brian, On 22/07/2020 05:00, Brian Woods wrote: > Modify the smmu driver so that it uses the iommu_fwspec helper > functions. This means both ARM IOMMU drivers will both use the > iommu_fwspec helper functions. > > Signed-off-by: Brian Woods <brian.woods@xilinx.com> > --- > > Interested in if combining the legacy and generic bindings paths are > worth or if Xen plans to depreicate legacy bindings at some point. The legacy binding is technically already deprecated in Linux. However, I don't think we can remove it completely until Linux does it. Ideally, I would like the legacy master to be probed as part of add_device rather than when the IOMMU initialization (see more below). > v1 -> v2 > - removed MAX_MASTER_STREAMIDS > - removed unneeded curly brackets > > xen/drivers/passthrough/arm/smmu.c | 81 +++++++++++++++++++---------------- > xen/drivers/passthrough/device_tree.c | 3 ++ > 2 files changed, 47 insertions(+), 37 deletions(-) > > diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c > index 94662a8..7a5c6cd 100644 > --- a/xen/drivers/passthrough/arm/smmu.c > +++ b/xen/drivers/passthrough/arm/smmu.c > @@ -49,6 +49,7 @@ > #include <asm/atomic.h> > #include <asm/device.h> > #include <asm/io.h> > +#include <asm/iommu_fwspec.h> > #include <asm/platform.h> > > /* Xen: The below defines are redefined within the file. Undef it */ > @@ -302,9 +303,6 @@ static struct iommu_group *iommu_group_get(struct device *dev) > > /***** Start of Linux SMMU code *****/ > > -/* Maximum number of stream IDs assigned to a single device */ > -#define MAX_MASTER_STREAMIDS MAX_PHANDLE_ARGS > - > /* Maximum number of context banks per SMMU */ > #define ARM_SMMU_MAX_CBS 128 > > @@ -597,8 +595,7 @@ struct arm_smmu_smr { > }; > > struct arm_smmu_master_cfg { > - int num_streamids; > - u16 streamids[MAX_MASTER_STREAMIDS]; > + struct iommu_fwspec *fwspec; > struct arm_smmu_smr *smrs; > }; > > @@ -779,7 +776,7 @@ static int register_smmu_master(struct arm_smmu_device *smmu, We originally intended to keep the SMMU driver as close as possible to Linux. It turns out to be quite difficult as they reworked a fair bit the IOMMU subsystem. Although, I would still like to document the change we made in the code. Could you add a comment maybe at the top of file to mention you added support for fwspec? > struct device *dev, > struct of_phandle_args *masterspec) > { > - int i; > + int i, ret = 0; > struct arm_smmu_master *master; > > master = find_smmu_master(smmu, masterspec->np); > @@ -790,34 +787,37 @@ static int register_smmu_master(struct arm_smmu_device *smmu, > return -EBUSY; > } > > - if (masterspec->args_count > MAX_MASTER_STREAMIDS) { > - dev_err(dev, > - "reached maximum number (%d) of stream IDs for master device %s\n", > - MAX_MASTER_STREAMIDS, masterspec->np->name); > - return -ENOSPC; > - } > - > master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL); > if (!master) > return -ENOMEM; > + master->of_node = masterspec->np; > > - master->of_node = masterspec->np; > - master->cfg.num_streamids = masterspec->args_count; > + ret = iommu_fwspec_init(&master->of_node->dev, smmu->dev); > + if (ret) { > + kfree(master); > + return ret; > + } > + master->cfg.fwspec = dev_iommu_fwspec_get(&master->of_node->dev); > + > + /* adding the ids here */ > + ret = iommu_fwspec_add_ids(&masterspec->np->dev, > + masterspec->args, > + masterspec->args_count); > + if (ret) > + return ret; > > /* Xen: Let Xen know that the device is protected by an SMMU */ > dt_device_set_protected(masterspec->np); > > - for (i = 0; i < master->cfg.num_streamids; ++i) { > - u16 streamid = masterspec->args[i]; > - > - if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) && > - (streamid >= smmu->num_mapping_groups)) { > - dev_err(dev, > - "stream ID for master device %s greater than maximum allowed (%d)\n", > - masterspec->np->name, smmu->num_mapping_groups); > - return -ERANGE; > + if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH)) { > + for (i = 0; i < master->cfg.fwspec->num_ids; ++i) { > + if (masterspec->args[i] >= smmu->num_mapping_groups) { > + dev_err(dev, > + "stream ID for master device %s greater than maximum allowed (%d)\n", > + masterspec->np->name, smmu->num_mapping_groups); > + return -ERANGE; > + } > } > - master->cfg.streamids[i] = streamid; > } > return insert_smmu_master(smmu, master); > } > @@ -1397,15 +1397,15 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu, > if (cfg->smrs) > return -EEXIST; > > - smrs = kmalloc_array(cfg->num_streamids, sizeof(*smrs), GFP_KERNEL); > + smrs = kmalloc_array(cfg->fwspec->num_ids, sizeof(*smrs), GFP_KERNEL); > if (!smrs) { > dev_err(smmu->dev, "failed to allocate %d SMRs\n", > - cfg->num_streamids); > + cfg->fwspec->num_ids); > return -ENOMEM; > } > > /* Allocate the SMRs on the SMMU */ > - for (i = 0; i < cfg->num_streamids; ++i) { > + for (i = 0; i < cfg->fwspec->num_ids; ++i) { > int idx = __arm_smmu_alloc_bitmap(smmu->smr_map, 0, > smmu->num_mapping_groups); > if (IS_ERR_VALUE(idx)) { > @@ -1416,12 +1416,12 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu, > smrs[i] = (struct arm_smmu_smr) { > .idx = idx, > .mask = 0, /* We don't currently share SMRs */ > - .id = cfg->streamids[i], > + .id = cfg->fwspec->ids[i], > }; > } > > /* It worked! Now, poke the actual hardware */ > - for (i = 0; i < cfg->num_streamids; ++i) { > + for (i = 0; i < cfg->fwspec->num_ids; ++i) { > u32 reg = SMR_VALID | smrs[i].id << SMR_ID_SHIFT | > smrs[i].mask << SMR_MASK_SHIFT; > writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_SMR(smrs[i].idx)); > @@ -1448,7 +1448,7 @@ static void arm_smmu_master_free_smrs(struct arm_smmu_device *smmu, > return; > > /* Invalidate the SMRs before freeing back to the allocator */ > - for (i = 0; i < cfg->num_streamids; ++i) { > + for (i = 0; i < cfg->fwspec->num_ids; ++i) { > u8 idx = smrs[i].idx; > > writel_relaxed(~SMR_VALID, gr0_base + ARM_SMMU_GR0_SMR(idx)); > @@ -1471,10 +1471,10 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain, > if (ret) > return ret == -EEXIST ? 0 : ret; > > - for (i = 0; i < cfg->num_streamids; ++i) { > + for (i = 0; i < cfg->fwspec->num_ids; ++i) { > u32 idx, s2cr; > > - idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i]; > + idx = cfg->smrs ? cfg->smrs[i].idx : cfg->fwspec->ids[i]; > s2cr = S2CR_TYPE_TRANS | > (smmu_domain->cfg.cbndx << S2CR_CBNDX_SHIFT); > writel_relaxed(s2cr, gr0_base + ARM_SMMU_GR0_S2CR(idx)); > @@ -1499,8 +1499,8 @@ static void arm_smmu_domain_remove_master(struct arm_smmu_domain *smmu_domain, > * that it can be re-allocated immediately. > * Xen: Unlike Linux, any access to non-configured stream will fault. > */ > - for (i = 0; i < cfg->num_streamids; ++i) { > - u32 idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i]; > + for (i = 0; i < cfg->fwspec->num_ids; ++i) { > + u32 idx = cfg->smrs ? cfg->smrs[i].idx : cfg->fwspec->ids[i]; > > writel_relaxed(S2CR_TYPE_FAULT, > gr0_base + ARM_SMMU_GR0_S2CR(idx)); > @@ -1924,14 +1924,21 @@ static int arm_smmu_add_device(struct device *dev) > ret = -ENOMEM; > goto out_put_group; > } > + cfg->fwspec = kzalloc(sizeof(struct iommu_fwspec), GFP_KERNEL); > + if (!cfg->fwspec) { > + kfree(cfg); > + ret = -ENOMEM; > + goto out_put_group; > + } > + iommu_fwspec_init(dev, smmu->dev); > > - cfg->num_streamids = 1; > + cfg->fwspec->num_ids = 1; > /* > * Assume Stream ID == Requester ID for now. > * We need a way to describe the ID mappings in FDT. > */ > pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid, > - &cfg->streamids[0]); > + &cfg->fwspec->ids[0]); > releasefn = __arm_smmu_release_pci_iommudata; > } else { > struct arm_smmu_master *master; > diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c > index 999b831..acf6b62 100644 > --- a/xen/drivers/passthrough/device_tree.c > +++ b/xen/drivers/passthrough/device_tree.c > @@ -140,6 +140,9 @@ int iommu_add_dt_device(struct dt_device_node *np) > if ( !ops ) > return -EINVAL; > > + if ( dt_device_is_protected(np) ) > + return 0; With the fwspec in place, I would have hoped we can remove an specific hack for the SMMU in the generic DT code. Could you instead explore whether it is possible to initialize the legacy master from add_device? > + > if ( dev_iommu_fwspec_get(dev) ) > return -EEXIST; > >
diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c index 94662a8..7a5c6cd 100644 --- a/xen/drivers/passthrough/arm/smmu.c +++ b/xen/drivers/passthrough/arm/smmu.c @@ -49,6 +49,7 @@ #include <asm/atomic.h> #include <asm/device.h> #include <asm/io.h> +#include <asm/iommu_fwspec.h> #include <asm/platform.h> /* Xen: The below defines are redefined within the file. Undef it */ @@ -302,9 +303,6 @@ static struct iommu_group *iommu_group_get(struct device *dev) /***** Start of Linux SMMU code *****/ -/* Maximum number of stream IDs assigned to a single device */ -#define MAX_MASTER_STREAMIDS MAX_PHANDLE_ARGS - /* Maximum number of context banks per SMMU */ #define ARM_SMMU_MAX_CBS 128 @@ -597,8 +595,7 @@ struct arm_smmu_smr { }; struct arm_smmu_master_cfg { - int num_streamids; - u16 streamids[MAX_MASTER_STREAMIDS]; + struct iommu_fwspec *fwspec; struct arm_smmu_smr *smrs; }; @@ -779,7 +776,7 @@ static int register_smmu_master(struct arm_smmu_device *smmu, struct device *dev, struct of_phandle_args *masterspec) { - int i; + int i, ret = 0; struct arm_smmu_master *master; master = find_smmu_master(smmu, masterspec->np); @@ -790,34 +787,37 @@ static int register_smmu_master(struct arm_smmu_device *smmu, return -EBUSY; } - if (masterspec->args_count > MAX_MASTER_STREAMIDS) { - dev_err(dev, - "reached maximum number (%d) of stream IDs for master device %s\n", - MAX_MASTER_STREAMIDS, masterspec->np->name); - return -ENOSPC; - } - master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL); if (!master) return -ENOMEM; + master->of_node = masterspec->np; - master->of_node = masterspec->np; - master->cfg.num_streamids = masterspec->args_count; + ret = iommu_fwspec_init(&master->of_node->dev, smmu->dev); + if (ret) { + kfree(master); + return ret; + } + master->cfg.fwspec = dev_iommu_fwspec_get(&master->of_node->dev); + + /* adding the ids here */ + ret = iommu_fwspec_add_ids(&masterspec->np->dev, + masterspec->args, + masterspec->args_count); + if (ret) + return ret; /* Xen: Let Xen know that the device is protected by an SMMU */ dt_device_set_protected(masterspec->np); - for (i = 0; i < master->cfg.num_streamids; ++i) { - u16 streamid = masterspec->args[i]; - - if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) && - (streamid >= smmu->num_mapping_groups)) { - dev_err(dev, - "stream ID for master device %s greater than maximum allowed (%d)\n", - masterspec->np->name, smmu->num_mapping_groups); - return -ERANGE; + if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH)) { + for (i = 0; i < master->cfg.fwspec->num_ids; ++i) { + if (masterspec->args[i] >= smmu->num_mapping_groups) { + dev_err(dev, + "stream ID for master device %s greater than maximum allowed (%d)\n", + masterspec->np->name, smmu->num_mapping_groups); + return -ERANGE; + } } - master->cfg.streamids[i] = streamid; } return insert_smmu_master(smmu, master); } @@ -1397,15 +1397,15 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu, if (cfg->smrs) return -EEXIST; - smrs = kmalloc_array(cfg->num_streamids, sizeof(*smrs), GFP_KERNEL); + smrs = kmalloc_array(cfg->fwspec->num_ids, sizeof(*smrs), GFP_KERNEL); if (!smrs) { dev_err(smmu->dev, "failed to allocate %d SMRs\n", - cfg->num_streamids); + cfg->fwspec->num_ids); return -ENOMEM; } /* Allocate the SMRs on the SMMU */ - for (i = 0; i < cfg->num_streamids; ++i) { + for (i = 0; i < cfg->fwspec->num_ids; ++i) { int idx = __arm_smmu_alloc_bitmap(smmu->smr_map, 0, smmu->num_mapping_groups); if (IS_ERR_VALUE(idx)) { @@ -1416,12 +1416,12 @@ static int arm_smmu_master_configure_smrs(struct arm_smmu_device *smmu, smrs[i] = (struct arm_smmu_smr) { .idx = idx, .mask = 0, /* We don't currently share SMRs */ - .id = cfg->streamids[i], + .id = cfg->fwspec->ids[i], }; } /* It worked! Now, poke the actual hardware */ - for (i = 0; i < cfg->num_streamids; ++i) { + for (i = 0; i < cfg->fwspec->num_ids; ++i) { u32 reg = SMR_VALID | smrs[i].id << SMR_ID_SHIFT | smrs[i].mask << SMR_MASK_SHIFT; writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_SMR(smrs[i].idx)); @@ -1448,7 +1448,7 @@ static void arm_smmu_master_free_smrs(struct arm_smmu_device *smmu, return; /* Invalidate the SMRs before freeing back to the allocator */ - for (i = 0; i < cfg->num_streamids; ++i) { + for (i = 0; i < cfg->fwspec->num_ids; ++i) { u8 idx = smrs[i].idx; writel_relaxed(~SMR_VALID, gr0_base + ARM_SMMU_GR0_SMR(idx)); @@ -1471,10 +1471,10 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain, if (ret) return ret == -EEXIST ? 0 : ret; - for (i = 0; i < cfg->num_streamids; ++i) { + for (i = 0; i < cfg->fwspec->num_ids; ++i) { u32 idx, s2cr; - idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i]; + idx = cfg->smrs ? cfg->smrs[i].idx : cfg->fwspec->ids[i]; s2cr = S2CR_TYPE_TRANS | (smmu_domain->cfg.cbndx << S2CR_CBNDX_SHIFT); writel_relaxed(s2cr, gr0_base + ARM_SMMU_GR0_S2CR(idx)); @@ -1499,8 +1499,8 @@ static void arm_smmu_domain_remove_master(struct arm_smmu_domain *smmu_domain, * that it can be re-allocated immediately. * Xen: Unlike Linux, any access to non-configured stream will fault. */ - for (i = 0; i < cfg->num_streamids; ++i) { - u32 idx = cfg->smrs ? cfg->smrs[i].idx : cfg->streamids[i]; + for (i = 0; i < cfg->fwspec->num_ids; ++i) { + u32 idx = cfg->smrs ? cfg->smrs[i].idx : cfg->fwspec->ids[i]; writel_relaxed(S2CR_TYPE_FAULT, gr0_base + ARM_SMMU_GR0_S2CR(idx)); @@ -1924,14 +1924,21 @@ static int arm_smmu_add_device(struct device *dev) ret = -ENOMEM; goto out_put_group; } + cfg->fwspec = kzalloc(sizeof(struct iommu_fwspec), GFP_KERNEL); + if (!cfg->fwspec) { + kfree(cfg); + ret = -ENOMEM; + goto out_put_group; + } + iommu_fwspec_init(dev, smmu->dev); - cfg->num_streamids = 1; + cfg->fwspec->num_ids = 1; /* * Assume Stream ID == Requester ID for now. * We need a way to describe the ID mappings in FDT. */ pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid, - &cfg->streamids[0]); + &cfg->fwspec->ids[0]); releasefn = __arm_smmu_release_pci_iommudata; } else { struct arm_smmu_master *master; diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c index 999b831..acf6b62 100644 --- a/xen/drivers/passthrough/device_tree.c +++ b/xen/drivers/passthrough/device_tree.c @@ -140,6 +140,9 @@ int iommu_add_dt_device(struct dt_device_node *np) if ( !ops ) return -EINVAL; + if ( dt_device_is_protected(np) ) + return 0; + if ( dev_iommu_fwspec_get(dev) ) return -EEXIST;
Modify the smmu driver so that it uses the iommu_fwspec helper functions. This means both ARM IOMMU drivers will both use the iommu_fwspec helper functions. Signed-off-by: Brian Woods <brian.woods@xilinx.com> --- Interested in if combining the legacy and generic bindings paths are worth or if Xen plans to depreicate legacy bindings at some point. v1 -> v2 - removed MAX_MASTER_STREAMIDS - removed unneeded curly brackets xen/drivers/passthrough/arm/smmu.c | 81 +++++++++++++++++++---------------- xen/drivers/passthrough/device_tree.c | 3 ++ 2 files changed, 47 insertions(+), 37 deletions(-)