[Freedreno] [PATCH v2 4/6] drm/msm: Add support to create a local pagetable

Rob Clark robdclark at gmail.com
Tue Jul 7 14:41:08 UTC 2020


On Tue, Jul 7, 2020 at 4:36 AM Robin Murphy <robin.murphy at arm.com> wrote:
>
> On 2020-06-26 21:04, Jordan Crouse wrote:
> > Add support to create a io-pgtable for use by targets that support
> > per-instance pagetables.  In order to support per-instance pagetables the
> > GPU SMMU device needs to have the qcom,adreno-smmu compatible string and
> > split pagetables and auxiliary domains need to be supported and enabled.
> >
> > Signed-off-by: Jordan Crouse <jcrouse at codeaurora.org>
> > ---
> >
> >   drivers/gpu/drm/msm/msm_gpummu.c |   2 +-
> >   drivers/gpu/drm/msm/msm_iommu.c  | 180 ++++++++++++++++++++++++++++++-
> >   drivers/gpu/drm/msm/msm_mmu.h    |  16 ++-
> >   3 files changed, 195 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
> > index 310a31b05faa..aab121f4beb7 100644
> > --- a/drivers/gpu/drm/msm/msm_gpummu.c
> > +++ b/drivers/gpu/drm/msm/msm_gpummu.c
> > @@ -102,7 +102,7 @@ struct msm_mmu *msm_gpummu_new(struct device *dev, struct msm_gpu *gpu)
> >       }
> >
> >       gpummu->gpu = gpu;
> > -     msm_mmu_init(&gpummu->base, dev, &funcs);
> > +     msm_mmu_init(&gpummu->base, dev, &funcs, MSM_MMU_GPUMMU);
> >
> >       return &gpummu->base;
> >   }
> > diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> > index 1b6635504069..f455c597f76d 100644
> > --- a/drivers/gpu/drm/msm/msm_iommu.c
> > +++ b/drivers/gpu/drm/msm/msm_iommu.c
> > @@ -4,15 +4,192 @@
> >    * Author: Rob Clark <robdclark at gmail.com>
> >    */
> >
> > +#include <linux/io-pgtable.h>
> >   #include "msm_drv.h"
> >   #include "msm_mmu.h"
> >
> >   struct msm_iommu {
> >       struct msm_mmu base;
> >       struct iommu_domain *domain;
> > +     struct iommu_domain *aux_domain;
> >   };
> > +
> >   #define to_msm_iommu(x) container_of(x, struct msm_iommu, base)
> >
> > +struct msm_iommu_pagetable {
> > +     struct msm_mmu base;
> > +     struct msm_mmu *parent;
> > +     struct io_pgtable_ops *pgtbl_ops;
> > +     phys_addr_t ttbr;
> > +     u32 asid;
> > +};
> > +
> > +static struct msm_iommu_pagetable *to_pagetable(struct msm_mmu *mmu)
> > +{
> > +     return container_of(mmu, struct msm_iommu_pagetable, base);
> > +}
> > +
> > +static int msm_iommu_pagetable_unmap(struct msm_mmu *mmu, u64 iova,
> > +             size_t size)
> > +{
> > +     struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
> > +     struct io_pgtable_ops *ops = pagetable->pgtbl_ops;
> > +     size_t unmapped = 0;
> > +
> > +     /* Unmap the block one page at a time */
> > +     while (size) {
> > +             unmapped += ops->unmap(ops, iova, 4096, NULL);
> > +             iova += 4096;
> > +             size -= 4096;
> > +     }
> > +
> > +     iommu_flush_tlb_all(to_msm_iommu(pagetable->parent)->domain);
> > +
> > +     return (unmapped == size) ? 0 : -EINVAL;
> > +}
>
> Remember in patch #1 when you said "Then 'domain' can be used like any
> other iommu domain to map and unmap iova addresses in the pagetable."?
>
> This appears to be very much not that :/
>

I guess that comment is a bit stale.. the original plan was to create
an iommu_domain per set of pgtables, but at some point we realized
that by using the io-pgtable helpers directly, we would inflict a lot
less GPU-crazy on the iommu drivers

BR,
-R

> Robin.
>
> > +
> > +static int msm_iommu_pagetable_map(struct msm_mmu *mmu, u64 iova,
> > +             struct sg_table *sgt, size_t len, int prot)
> > +{
> > +     struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
> > +     struct io_pgtable_ops *ops = pagetable->pgtbl_ops;
> > +     struct scatterlist *sg;
> > +     size_t mapped = 0;
> > +     u64 addr = iova;
> > +     unsigned int i;
> > +
> > +     for_each_sg(sgt->sgl, sg, sgt->nents, i) {
> > +             size_t size = sg->length;
> > +             phys_addr_t phys = sg_phys(sg);
> > +
> > +             /* Map the block one page at a time */
> > +             while (size) {
> > +                     if (ops->map(ops, addr, phys, 4096, prot)) {
> > +                             msm_iommu_pagetable_unmap(mmu, iova, mapped);
> > +                             return -EINVAL;
> > +                     }
> > +
> > +                     phys += 4096;
> > +                     addr += 4096;
> > +                     size -= 4096;
> > +                     mapped += 4096;
> > +             }
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void msm_iommu_pagetable_destroy(struct msm_mmu *mmu)
> > +{
> > +     struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
> > +
> > +     free_io_pgtable_ops(pagetable->pgtbl_ops);
> > +     kfree(pagetable);
> > +}
> > +
> > +/*
> > + * Given a parent device, create and return an aux domain. This will enable the
> > + * TTBR0 region
> > + */
> > +static struct iommu_domain *msm_iommu_get_aux_domain(struct msm_mmu *parent)
> > +{
> > +     struct msm_iommu *iommu = to_msm_iommu(parent);
> > +     struct iommu_domain *domain;
> > +     int ret;
> > +
> > +     if (iommu->aux_domain)
> > +             return iommu->aux_domain;
> > +
> > +     if (!iommu_dev_has_feature(parent->dev, IOMMU_DEV_FEAT_AUX))
> > +             return ERR_PTR(-ENODEV);
> > +
> > +     domain = iommu_domain_alloc(&platform_bus_type);
> > +     if (!domain)
> > +             return ERR_PTR(-ENODEV);
> > +
> > +     ret = iommu_aux_attach_device(domain, parent->dev);
> > +     if (ret) {
> > +             iommu_domain_free(domain);
> > +             return ERR_PTR(ret);
> > +     }
> > +
> > +     iommu->aux_domain = domain;
> > +     return domain;
> > +}
> > +
> > +int msm_iommu_pagetable_params(struct msm_mmu *mmu,
> > +             phys_addr_t *ttbr, int *asid)
> > +{
> > +     struct msm_iommu_pagetable *pagetable;
> > +
> > +     if (mmu->type != MSM_MMU_IOMMU_PAGETABLE)
> > +             return -EINVAL;
> > +
> > +     pagetable = to_pagetable(mmu);
> > +
> > +     if (ttbr)
> > +             *ttbr = pagetable->ttbr;
> > +
> > +     if (asid)
> > +             *asid = pagetable->asid;
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct msm_mmu_funcs pagetable_funcs = {
> > +             .map = msm_iommu_pagetable_map,
> > +             .unmap = msm_iommu_pagetable_unmap,
> > +             .destroy = msm_iommu_pagetable_destroy,
> > +};
> > +
> > +struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
> > +{
> > +     static int next_asid = 16;
> > +     struct msm_iommu_pagetable *pagetable;
> > +     struct iommu_domain *aux_domain;
> > +     struct io_pgtable_cfg cfg;
> > +     int ret;
> > +
> > +     /* Make sure that the parent has a aux domain attached */
> > +     aux_domain = msm_iommu_get_aux_domain(parent);
> > +     if (IS_ERR(aux_domain))
> > +             return ERR_CAST(aux_domain);
> > +
> > +     /* Get the pagetable configuration from the aux domain */
> > +     ret = iommu_domain_get_attr(aux_domain, DOMAIN_ATTR_PGTABLE_CFG, &cfg);
> > +     if (ret)
> > +             return ERR_PTR(ret);
> > +
> > +     pagetable = kzalloc(sizeof(*pagetable), GFP_KERNEL);
> > +     if (!pagetable)
> > +             return ERR_PTR(-ENOMEM);
> > +
> > +     msm_mmu_init(&pagetable->base, parent->dev, &pagetable_funcs,
> > +             MSM_MMU_IOMMU_PAGETABLE);
> > +
> > +     cfg.tlb = NULL;
> > +
> > +     pagetable->pgtbl_ops = alloc_io_pgtable_ops(ARM_64_LPAE_S1,
> > +             &cfg, aux_domain);
> > +
> > +     if (!pagetable->pgtbl_ops) {
> > +             kfree(pagetable);
> > +             return ERR_PTR(-ENOMEM);
> > +     }
> > +
> > +
> > +     /* Needed later for TLB flush */
> > +     pagetable->parent = parent;
> > +     pagetable->ttbr = cfg.arm_lpae_s1_cfg.ttbr;
> > +
> > +     pagetable->asid = next_asid;
> > +     next_asid = (next_asid + 1)  % 255;
> > +     if (next_asid < 16)
> > +             next_asid = 16;
> > +
> > +     return &pagetable->base;
> > +}
> > +
> >   static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
> >               unsigned long iova, int flags, void *arg)
> >   {
> > @@ -40,6 +217,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
> >       if (iova & BIT_ULL(48))
> >               iova |= GENMASK_ULL(63, 49);
> >
> > +
> >       ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot);
> >       WARN_ON(!ret);
> >
> > @@ -85,7 +263,7 @@ struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
> >               return ERR_PTR(-ENOMEM);
> >
> >       iommu->domain = domain;
> > -     msm_mmu_init(&iommu->base, dev, &funcs);
> > +     msm_mmu_init(&iommu->base, dev, &funcs, MSM_MMU_IOMMU);
> >       iommu_set_fault_handler(domain, msm_fault_handler, iommu);
> >
> >       ret = iommu_attach_device(iommu->domain, dev);
> > diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
> > index 3a534ee59bf6..61ade89d9e48 100644
> > --- a/drivers/gpu/drm/msm/msm_mmu.h
> > +++ b/drivers/gpu/drm/msm/msm_mmu.h
> > @@ -17,18 +17,26 @@ struct msm_mmu_funcs {
> >       void (*destroy)(struct msm_mmu *mmu);
> >   };
> >
> > +enum msm_mmu_type {
> > +     MSM_MMU_GPUMMU,
> > +     MSM_MMU_IOMMU,
> > +     MSM_MMU_IOMMU_PAGETABLE,
> > +};
> > +
> >   struct msm_mmu {
> >       const struct msm_mmu_funcs *funcs;
> >       struct device *dev;
> >       int (*handler)(void *arg, unsigned long iova, int flags);
> >       void *arg;
> > +     enum msm_mmu_type type;
> >   };
> >
> >   static inline void msm_mmu_init(struct msm_mmu *mmu, struct device *dev,
> > -             const struct msm_mmu_funcs *funcs)
> > +             const struct msm_mmu_funcs *funcs, enum msm_mmu_type type)
> >   {
> >       mmu->dev = dev;
> >       mmu->funcs = funcs;
> > +     mmu->type = type;
> >   }
> >
> >   struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain);
> > @@ -41,7 +49,13 @@ static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg,
> >       mmu->handler = handler;
> >   }
> >
> > +struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent);
> > +
> >   void msm_gpummu_params(struct msm_mmu *mmu, dma_addr_t *pt_base,
> >               dma_addr_t *tran_error);
> >
> > +
> > +int msm_iommu_pagetable_params(struct msm_mmu *mmu, phys_addr_t *ttbr,
> > +             int *asid);
> > +
> >   #endif /* __MSM_MMU_H__ */
> >
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