drivers/gpu/drm/msm/msm_iommu.c

   1 /*
   2  * Copyright (C) 2013 Red Hat
   3  * Author: Rob Clark <robdclark@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "msm_drv.h"
  19 #include "msm_mmu.h"
  20
  21 struct msm_iommu {
  22         struct msm_mmu base;
  23         struct iommu_domain *domain;
  24 };
  25 #define to_msm_iommu(x) container_of(x, struct msm_iommu, base)
  26
  27 static int msm_fault_handler(struct iommu_domain *iommu, struct device *dev,
  28                 unsigned long iova, int flags, void *arg)
  29 {
  30         pr_warn_ratelimited("*** fault: iova=%08lx, flags=%d\n", iova, flags);
  31         return 0;
  32 }
  33
  34 static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
  35 {
  36         struct msm_iommu *iommu = to_msm_iommu(mmu);
  37         return iommu_attach_device(iommu->domain, mmu->dev);
  38 }
  39
  40 static void msm_iommu_detach(struct msm_mmu *mmu, const char **names, int cnt)
  41 {
  42         struct msm_iommu *iommu = to_msm_iommu(mmu);
  43         iommu_detach_device(iommu->domain, mmu->dev);
  44 }
  45
  46 static int msm_iommu_map(struct msm_mmu *mmu, uint32_t iova,
  47                 struct sg_table *sgt, unsigned len, int prot)
  48 {
  49         struct msm_iommu *iommu = to_msm_iommu(mmu);
  50         struct iommu_domain *domain = iommu->domain;
  51         struct scatterlist *sg;
  52         unsigned int da = iova;
  53         unsigned int i, j;
  54         int ret;
  55
  56         if (!domain || !sgt)
  57                 return -EINVAL;
  58
  59         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
  60                 u32 pa = sg_phys(sg) - sg->offset;
  61                 size_t bytes = sg->length + sg->offset;
  62
  63                 VERB("map[%d]: %08x %08x(%zx)", i, iova, pa, bytes);
  64
  65                 ret = iommu_map(domain, da, pa, bytes, prot);
  66                 if (ret)
  67                         goto fail;
  68
  69                 da += bytes;
  70         }
  71
  72         return 0;
  73
  74 fail:
  75         da = iova;
  76
  77         for_each_sg(sgt->sgl, sg, i, j) {
  78                 size_t bytes = sg->length + sg->offset;
  79                 iommu_unmap(domain, da, bytes);
  80                 da += bytes;
  81         }
  82         return ret;
  83 }
  84
  85 static int msm_iommu_unmap(struct msm_mmu *mmu, uint32_t iova,
  86                 struct sg_table *sgt, unsigned len)
  87 {
  88         struct msm_iommu *iommu = to_msm_iommu(mmu);
  89         struct iommu_domain *domain = iommu->domain;
  90         struct scatterlist *sg;
  91         unsigned int da = iova;
  92         int i;
  93
  94         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
  95                 size_t bytes = sg->length + sg->offset;
  96                 size_t unmapped;
  97
  98                 unmapped = iommu_unmap(domain, da, bytes);
  99                 if (unmapped < bytes)
 100                         return unmapped;
 101
 102                 VERB("unmap[%d]: %08x(%zx)", i, iova, bytes);
 103
 104                 BUG_ON(!PAGE_ALIGNED(bytes));
 105
 106                 da += bytes;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static void msm_iommu_destroy(struct msm_mmu *mmu)
 113 {
 114         struct msm_iommu *iommu = to_msm_iommu(mmu);
 115         iommu_domain_free(iommu->domain);
 116         kfree(iommu);
 117 }
 118
 119 static const struct msm_mmu_funcs funcs = {
 120                 .attach = msm_iommu_attach,
 121                 .detach = msm_iommu_detach,
 122                 .map = msm_iommu_map,
 123                 .unmap = msm_iommu_unmap,
 124                 .destroy = msm_iommu_destroy,
 125 };
 126
 127 struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
 128 {
 129         struct msm_iommu *iommu;
 130
 131         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
 132         if (!iommu)
 133                 return ERR_PTR(-ENOMEM);
 134
 135         iommu->domain = domain;
 136         msm_mmu_init(&iommu->base, dev, &funcs);
 137         iommu_set_fault_handler(domain, msm_fault_handler, dev);
 138
 139         return &iommu->base;
 140 }