On 08.05.2018 21:16, Dmitry Osipenko wrote: > GART aperture is shared by all devices, hence there is a single IOMMU > domain and group shared by these devices. Allocation of a group per > device only wastes resources and allowance of having more than one domain > is simply wrong because IOMMU mappings made by the users of "different" > domains will stomp on each other. > > Signed-off-by: Dmitry Osipenko <[email protected]> > --- > drivers/iommu/tegra-gart.c | 107 +++++++++---------------------------- > 1 file changed, 24 insertions(+), 83 deletions(-) > > diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c > index 5b2d27620350..ebc105c201bd 100644 > --- a/drivers/iommu/tegra-gart.c > +++ b/drivers/iommu/tegra-gart.c > @@ -19,7 +19,6 @@ > > #include <linux/io.h> > #include <linux/iommu.h> > -#include <linux/list.h> > #include <linux/module.h> > #include <linux/of_device.h> > #include <linux/slab.h> > @@ -44,22 +43,17 @@ > #define GART_PAGE_MASK \ > (~(GART_PAGE_SIZE - 1) & ~GART_ENTRY_PHYS_ADDR_VALID) > > -struct gart_client { > - struct device *dev; > - struct list_head list; > -}; > - > struct gart_device { > void __iomem *regs; > u32 *savedata; > u32 page_count; /* total remappable size */ > dma_addr_t iovmm_base; /* offset to vmm_area */ > spinlock_t pte_lock; /* for pagetable */ > - struct list_head client; > - spinlock_t client_lock; /* for client list */ > struct device *dev; > > struct iommu_device iommu; /* IOMMU Core handle */ > + struct iommu_group *group; /* Common IOMMU group */ > + struct gart_domain *domain; /* Unique IOMMU domain */ > > struct tegra_mc_gart_handle mc_gart_handle; > }; > @@ -169,81 +163,31 @@ static inline bool gart_iova_range_valid(struct > gart_device *gart, > static int gart_iommu_attach_dev(struct iommu_domain *domain, > struct device *dev) > { > - struct gart_domain *gart_domain = to_gart_domain(domain); > - struct gart_device *gart = gart_domain->gart; > - struct gart_client *client, *c; > - int err = 0; > - > - client = devm_kzalloc(gart->dev, sizeof(*c), GFP_KERNEL); > - if (!client) > - return -ENOMEM; > - client->dev = dev; > - > - spin_lock(&gart->client_lock); > - list_for_each_entry(c, &gart->client, list) { > - if (c->dev == dev) { > - dev_err(gart->dev, > - "%s is already attached\n", dev_name(dev)); > - err = -EINVAL; > - goto fail; > - } > - } > - list_add(&client->list, &gart->client); > - spin_unlock(&gart->client_lock); > - dev_dbg(gart->dev, "Attached %s\n", dev_name(dev)); > return 0; > - > -fail: > - devm_kfree(gart->dev, client); > - spin_unlock(&gart->client_lock); > - return err; > } > > static void gart_iommu_detach_dev(struct iommu_domain *domain, > struct device *dev) > { > - struct gart_domain *gart_domain = to_gart_domain(domain); > - struct gart_device *gart = gart_domain->gart; > - struct gart_client *c; > - > - spin_lock(&gart->client_lock); > - > - list_for_each_entry(c, &gart->client, list) { > - if (c->dev == dev) { > - list_del(&c->list); > - devm_kfree(gart->dev, c); > - dev_dbg(gart->dev, "Detached %s\n", dev_name(dev)); > - goto out; > - } > - } > - dev_err(gart->dev, "Couldn't find\n"); > -out: > - spin_unlock(&gart->client_lock); > } > > static struct iommu_domain *gart_iommu_domain_alloc(unsigned type) > { > - struct gart_domain *gart_domain; > - struct gart_device *gart; > - > - if (type != IOMMU_DOMAIN_UNMANAGED) > - return NULL; > + struct gart_device *gart = gart_handle; > > - gart = gart_handle; > - if (!gart) > + if (type != IOMMU_DOMAIN_UNMANAGED || gart->domain) > return NULL; > > - gart_domain = kzalloc(sizeof(*gart_domain), GFP_KERNEL); > - if (!gart_domain) > - return NULL; > - > - gart_domain->gart = gart; > - gart_domain->domain.geometry.aperture_start = gart->iovmm_base; > - gart_domain->domain.geometry.aperture_end = gart->iovmm_base + > + gart->domain = kzalloc(sizeof(*gart->domain), GFP_KERNEL); > + if (gart->domain) { > + gart->domain->domain.geometry.aperture_start = gart->iovmm_base; > + gart->domain->domain.geometry.aperture_end = gart->iovmm_base + > gart->page_count * GART_PAGE_SIZE - 1; > - gart_domain->domain.geometry.force_aperture = true; > + gart->domain->domain.geometry.force_aperture = true; > + gart->domain->gart = gart; > + } > > - return &gart_domain->domain; > + return &gart->domain->domain; > }
I've missed a NULL-check and locking here, this will be fixed in v2. For now I'll wait for the review comments (please review).
