drm: drop redundant drm_file->is_master

The drm_file->is_master field is redundant as it's equivalent to:
    drm_file->master && drm_file->master == drm_file->minor->master

1) "=>"
  Whenever we set drm_file->is_master, we also set:
      drm_file->minor->master = drm_file->master;

  Whenever we clear drm_file->is_master, we also call:
      drm_master_put(&drm_file->minor->master);
  which implicitly clears it to NULL.

2) "<="
  minor->master cannot be set if it is non-NULL. Therefore, it stays as
  is unless a file drops it.

  If minor->master is NULL, it is only set by places that also adjust
  drm_file->is_master.

Therefore, we can safely drop is_master and replace it by an inline helper
that matches:
    drm_file->master && drm_file->master == drm_file->minor->master

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 3c4a62169f288237fa19ade7e0829467d097dd04..670b5eb13c87a3efd667cb7a51f4ede4e27a6de1 100644 (file)
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3243,7 +3243,7 @@ int drm_mode_getfb(struct drm_device *dev,
        r->bpp = fb->bits_per_pixel;
        r->pitch = fb->pitches[0];
        if (fb->funcs->create_handle) {
-               if (file_priv->is_master || capable(CAP_SYS_ADMIN) ||
+               if (drm_is_master(file_priv) || capable(CAP_SYS_ADMIN) ||
                    drm_is_control_client(file_priv)) {
                        ret = fb->funcs->create_handle(fb, file_priv,
                                                       &r->handle);

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 0cc182745e31fc3529e3528a16cc451df17fc0f1..7aa8121d1323fbf45f0ad017c6d31941bbeba20a 100644 (file)
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -307,7 +307,7 @@ static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
                return -EACCES;
 
        /* MASTER is only for master or control clients */
-       if (unlikely((flags & DRM_MASTER) && !file_priv->is_master &&
+       if (unlikely((flags & DRM_MASTER) && !drm_is_master(file_priv) &&
                     !drm_is_control_client(file_priv)))
                return -EACCES;
 

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 55143f7747f37be6fdb07658ae24c0d5c7a9e24a..53435e07fa8df5eff87ffd4f709df3853c280dc9 100644 (file)
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -233,7 +233,6 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
                        goto out_close;
                }
 
-               priv->is_master = 1;
                /* take another reference for the copy in the local file priv */
                priv->master = drm_master_get(priv->minor->master);
                priv->authenticated = 1;
@@ -461,7 +460,7 @@ int drm_release(struct inode *inode, struct file *filp)
 
        mutex_lock(&dev->master_mutex);
 
-       if (file_priv->is_master) {
+       if (drm_is_master(file_priv)) {
                struct drm_master *master = file_priv->master;
                struct drm_file *temp;
 
@@ -497,7 +496,6 @@ int drm_release(struct inode *inode, struct file *filp)
        /* drop the master reference held by the file priv */
        if (file_priv->master)
                drm_master_put(&file_priv->master);
-       file_priv->is_master = 0;
        mutex_unlock(&dev->master_mutex);
 
        mutex_lock(&dev->struct_mutex);

diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index f6452682141b5fd25773153233fb97983dafbc40..786401cd5f606b80548ab26a4b1f40eecd1a50c6 100644 (file)
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -111,7 +111,7 @@ int drm_lock(struct drm_device *dev, void *data, struct drm_file *file_priv)
        /* don't set the block all signals on the master process for now 
         * really probably not the correct answer but lets us debug xkb
         * xserver for now */
-       if (!file_priv->is_master) {
+       if (!drm_is_master(file_priv)) {
                sigemptyset(&dev->sigmask);
                sigaddset(&dev->sigmask, SIGSTOP);
                sigaddset(&dev->sigmask, SIGTSTP);

diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index 233ea208c9fe8f783d282986dad2edde192bcf31..18c9b3d8201e35cf4e21eeb84c4c8431563ffd06 100644 (file)
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -177,7 +177,7 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data,
        int ret = 0;
 
        mutex_lock(&dev->master_mutex);
-       if (file_priv->is_master)
+       if (drm_is_master(file_priv))
                goto out_unlock;
 
        if (file_priv->minor->master) {
@@ -191,13 +191,10 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data,
        }
 
        file_priv->minor->master = drm_master_get(file_priv->master);
-       file_priv->is_master = 1;
        if (dev->driver->master_set) {
                ret = dev->driver->master_set(dev, file_priv, false);
-               if (unlikely(ret != 0)) {
-                       file_priv->is_master = 0;
+               if (unlikely(ret != 0))
                        drm_master_put(&file_priv->minor->master);
-               }
        }
 
 out_unlock:
@@ -211,7 +208,7 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
        int ret = -EINVAL;
 
        mutex_lock(&dev->master_mutex);
-       if (!file_priv->is_master)
+       if (!drm_is_master(file_priv))
                goto out_unlock;
 
        if (!file_priv->minor->master)
@@ -221,7 +218,6 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
        if (dev->driver->master_drop)
                dev->driver->master_drop(dev, file_priv, false);
        drm_master_put(&file_priv->minor->master);
-       file_priv->is_master = 0;
 
 out_unlock:
        mutex_unlock(&dev->master_mutex);

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 60998fc4e5b22147687db554a4c80f27d08e1bea..2dd19da6b4b3e00c35bb2b2b854b7c4e2f87714f 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1260,7 +1260,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 
        flags = 0;
        if (args->flags & I915_EXEC_SECURE) {
-               if (!file->is_master || !capable(CAP_SYS_ADMIN))
+               if (!drm_is_master(file) || !capable(CAP_SYS_ADMIN))
                    return -EPERM;
 
                flags |= I915_DISPATCH_SECURE;
@@ -1369,7 +1369,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
                ret = i915_parse_cmds(ring,
                                      batch_obj,
                                      args->batch_start_offset,
-                                     file->is_master);
+                                     drm_is_master(file));
                if (ret)
                        goto err;
 

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 18b54acacfbb813335c00964117613a232840c94..63c4d6f0281ed5589c19cf9ba9a68bbf9de31706 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -990,7 +990,7 @@ static struct vmw_master *vmw_master_check(struct drm_device *dev,
        if (unlikely(ret != 0))
                return ERR_PTR(-ERESTARTSYS);
 
-       if (file_priv->is_master) {
+       if (drm_is_master(file_priv)) {
                mutex_unlock(&dev->master_mutex);
                return NULL;
        }

diff --git a/drivers/staging/imx-drm/imx-drm-core.c b/drivers/staging/imx-drm/imx-drm-core.c
index 6f54ff4f937277e37af48ba63796b4d9c605609f..72913b2990477d4fa83b39c909d9beae74b52b8c 100644 (file)
--- a/drivers/staging/imx-drm/imx-drm-core.c
+++ b/drivers/staging/imx-drm/imx-drm-core.c
@@ -182,7 +182,7 @@ static void imx_drm_driver_preclose(struct drm_device *drm,
 {
        int i;
 
-       if (!file->is_master)
+       if (!drm_is_master(file))
                return;
 
        for (i = 0; i < MAX_CRTC; i++)

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 80889982d19612b5c1ca9d73bdfe5ceecd540ce2..6ede53712d7bc0d745b3dd467118867d65417e85 100644 (file)
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -387,8 +387,6 @@ struct drm_prime_file_private {
 struct drm_file {
        unsigned always_authenticated :1;
        unsigned authenticated :1;
-       /* Whether we're master for a minor. Protected by master_mutex */
-       unsigned is_master :1;
        /* true when the client has asked us to expose stereo 3D mode flags */
        unsigned stereo_allowed :1;
        /*
@@ -1034,7 +1032,7 @@ struct drm_device {
        /** \name Locks */
        /*@{ */
        struct mutex struct_mutex;      /**< For others */
-       struct mutex master_mutex;      /**< For drm_minor::master and drm_file::is_master */
+       struct mutex master_mutex;      /**< For drm_minor::master */
        /*@} */
 
        /** \name Usage Counters */
@@ -1172,6 +1170,21 @@ static inline bool drm_is_primary_client(const struct drm_file *file_priv)
        return file_priv->minor->type == DRM_MINOR_LEGACY;
 }
 
+/**
+ * drm_is_master() - Check whether a DRM open-file is DRM-Master
+ * @file: DRM open-file context
+ *
+ * This checks whether a DRM open-file context is owner of the master context
+ * attached to it. If a file owns a master context, it's called DRM-Master.
+ * Per DRM device, only one such file can be DRM-Master at a time.
+ *
+ * Returns: True if the file is DRM-Master, otherwise false.
+ */
+static inline bool drm_is_master(const struct drm_file *file)
+{
+       return file->master && file->master == file->minor->master;
+}
+
 /******************************************************************/
 /** \name Internal function definitions */
 /*@{*/