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         DBG("*** fault: iova=%08lx, flags=%d", 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 drm_device *dev = mmu->dev;
  37         struct msm_iommu *iommu = to_msm_iommu(mmu);
  38         int i, ret;
  39
  40         for (i = 0; i < cnt; i++) {
  41                 struct device *msm_iommu_get_ctx(const char *ctx_name);
  42                 struct device *ctx = msm_iommu_get_ctx(names[i]);
  43                 if (IS_ERR_OR_NULL(ctx))
  44                         continue;
  45                 ret = iommu_attach_device(iommu->domain, ctx);
  46                 if (ret) {
  47                         dev_warn(dev->dev, "could not attach iommu to %s", names[i]);
  48                         return ret;
  49                 }
  50         }
  51
  52         return 0;
  53 }
  54
  55 static int msm_iommu_map(struct msm_mmu *mmu, uint32_t iova,
  56                 struct sg_table *sgt, unsigned len, int prot)
  57 {
  58         struct msm_iommu *iommu = to_msm_iommu(mmu);
  59         struct iommu_domain *domain = iommu->domain;
  60         struct scatterlist *sg;
  61         unsigned int da = iova;
  62         unsigned int i, j;
  63         int ret;
  64
  65         if (!domain || !sgt)
  66                 return -EINVAL;
  67
  68         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
  69                 u32 pa = sg_phys(sg) - sg->offset;
  70                 size_t bytes = sg->length + sg->offset;
  71
  72                 VERB("map[%d]: %08x %08x(%x)", i, iova, pa, bytes);
  73
  74                 ret = iommu_map(domain, da, pa, bytes, prot);
  75                 if (ret)
  76                         goto fail;
  77
  78                 da += bytes;
  79         }
  80
  81         return 0;
  82
  83 fail:
  84         da = iova;
  85
  86         for_each_sg(sgt->sgl, sg, i, j) {
  87                 size_t bytes = sg->length + sg->offset;
  88                 iommu_unmap(domain, da, bytes);
  89                 da += bytes;
  90         }
  91         return ret;
  92 }
  93
  94 static int msm_iommu_unmap(struct msm_mmu *mmu, uint32_t iova,
  95                 struct sg_table *sgt, unsigned len)
  96 {
  97         struct msm_iommu *iommu = to_msm_iommu(mmu);
  98         struct iommu_domain *domain = iommu->domain;
  99         struct scatterlist *sg;
 100         unsigned int da = iova;
 101         int i;
 102
 103         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 104                 size_t bytes = sg->length + sg->offset;
 105                 size_t unmapped;
 106
 107                 unmapped = iommu_unmap(domain, da, bytes);
 108                 if (unmapped < bytes)
 109                         return unmapped;
 110
 111                 VERB("unmap[%d]: %08x(%x)", i, iova, bytes);
 112
 113                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 114
 115                 da += bytes;
 116         }
 117
 118         return 0;
 119 }
 120
 121 static void msm_iommu_destroy(struct msm_mmu *mmu)
 122 {
 123         struct msm_iommu *iommu = to_msm_iommu(mmu);
 124         iommu_domain_free(iommu->domain);
 125         kfree(iommu);
 126 }
 127
 128 static const struct msm_mmu_funcs funcs = {
 129                 .attach = msm_iommu_attach,
 130                 .map = msm_iommu_map,
 131                 .unmap = msm_iommu_unmap,
 132                 .destroy = msm_iommu_destroy,
 133 };
 134
 135 struct msm_mmu *msm_iommu_new(struct drm_device *dev, struct iommu_domain *domain)
 136 {
 137         struct msm_iommu *iommu;
 138
 139         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
 140         if (!iommu)
 141                 return ERR_PTR(-ENOMEM);
 142
 143         iommu->domain = domain;
 144         msm_mmu_init(&iommu->base, dev, &funcs);
 145         iommu_set_fault_handler(domain, msm_fault_handler, dev);
 146
 147         return &iommu->base;
 148 }