1 files changed, 131 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c b/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c
index e85cec9c..73c9d084 100644
--- a/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c
+++ b/drivers/gpu/nvgpu/os/linux/ioctl_ctrl.c
@@ -57,6 +57,10 @@ struct gk20a_ctrl_priv {
         struct nvgpu_clk_session *clk_session;
 
         struct nvgpu_list_node list;
+        struct {
+                struct vm_area_struct *vma;
+                unsigned long flags;
+        } usermode_vma;
 };
 
 static inline struct gk20a_ctrl_priv *
@@ -1919,3 +1923,130 @@ long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg
 
         return err;
 }
+
+static void usermode_vma_close(struct vm_area_struct *vma)
+{
+        struct gk20a_ctrl_priv *priv = vma->vm_private_data;
+        struct gk20a *g = priv->g;
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        nvgpu_mutex_acquire(&l->ctrl.privs_lock);
+        priv->usermode_vma.vma = NULL;
+        nvgpu_mutex_release(&l->ctrl.privs_lock);
+}
+
+struct vm_operations_struct usermode_vma_ops = {
+        /* no .open - we use VM_DONTCOPY and don't support fork */
+        .close = usermode_vma_close,
+};
+
+int gk20a_ctrl_dev_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+        struct gk20a_ctrl_priv *priv = filp->private_data;
+        struct gk20a *g = priv->g;
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+        u64 addr;
+        int err;
+
+        if (g->ops.fifo.usermode_base == NULL)
+                return -ENOSYS;
+
+        if (priv->usermode_vma.vma != NULL)
+                return -EBUSY;
+
+        if (vma->vm_end - vma->vm_start != SZ_4K)
+                return -EINVAL;
+
+        if (vma->vm_pgoff != 0UL)
+                return -EINVAL;
+
+        addr = l->regs_bus_addr + g->ops.fifo.usermode_base(g);
+
+        /* Sync with poweron/poweroff, and require valid regs */
+        err = gk20a_busy(g);
+        if (err) {
+                return err;
+        }
+
+        nvgpu_mutex_acquire(&l->ctrl.privs_lock);
+
+        vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
+                VM_DONTDUMP | VM_PFNMAP;
+        vma->vm_ops = &usermode_vma_ops;
+        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+        err = io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
+                        vma->vm_end - vma->vm_start, vma->vm_page_prot);
+        if (!err) {
+                priv->usermode_vma.vma = vma;
+                priv->usermode_vma.flags = vma->vm_flags;
+                vma->vm_private_data = priv;
+        }
+        nvgpu_mutex_release(&l->ctrl.privs_lock);
+
+        gk20a_idle(g);
+
+        return err;
+}
+
+static void alter_usermode_mapping(struct gk20a *g,
+                struct gk20a_ctrl_priv *priv,
+                bool poweroff)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+        struct vm_area_struct *vma = priv->usermode_vma.vma;
+        u64 addr;
+        int err;
+
+        if (!vma) {
+                /* Nothing to do - no mmap called */
+                return;
+        }
+
+        addr = l->regs_bus_addr + g->ops.fifo.usermode_base(g);
+
+        down_write(&vma->vm_mm->mmap_sem);
+
+        if (poweroff) {
+                err = zap_vma_ptes(vma, vma->vm_start, SZ_4K);
+                if (err == 0) {
+                        vma->vm_flags = VM_NONE;
+                } else {
+                        nvgpu_err(g, "can't remove usermode mapping");
+                }
+        } else {
+                vma->vm_flags = priv->usermode_vma.flags;
+                err = io_remap_pfn_range(vma, vma->vm_start,
+                                addr >> PAGE_SHIFT,
+                                SZ_4K, vma->vm_page_prot);
+                if (err != 0) {
+                        nvgpu_err(g, "can't restore usermode mapping");
+                        vma->vm_flags = VM_NONE;
+                }
+        }
+
+        up_write(&vma->vm_mm->mmap_sem);
+}
+
+static void alter_usermode_mappings(struct gk20a *g, bool poweroff)
+{
+        struct gk20a_ctrl_priv *priv;
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        nvgpu_mutex_acquire(&l->ctrl.privs_lock);
+        nvgpu_list_for_each_entry(priv, &l->ctrl.privs,
+                        gk20a_ctrl_priv, list) {
+                alter_usermode_mapping(g, priv, poweroff);
+        }
+        nvgpu_mutex_release(&l->ctrl.privs_lock);
+}
+
+void nvgpu_hide_usermode_for_poweroff(struct gk20a *g)
+{
+        alter_usermode_mappings(g, true);
+}
+
+void nvgpu_restore_usermode_for_poweron(struct gk20a *g)
+{
+        alter_usermode_mappings(g, false);
+}