Revision 31a55cf145f2e3d74a7488e86bd0b33b64250fce authored by Dave Airlie on 19 March 2015, 04:01:42 UTC, committed by Dave Airlie on 19 March 2015, 04:01:42 UTC
   Some urgent regression fixes to booting failures Exynos DRM occured.

   Summary:
   - Fix two urgent null pointer dereference bugs in case of enabling
     or disabling IOMMU. There was two cases to these issues.
     One is that plane->crtc is accessed by exynos_disable_plane()
     when device tree binding is broken so device driver tries
     to release, which means that the mode set operation isn't invoked yet
     so plane->crtc is still NULL and exynos_disable_plane() will access
     NULL pointer. This issue is fixed by checking if the plane->crtc
     is NULL or not in exynos_disable_plane()

     Other is that fimd_wait_for_vblank() is called to avoid from page fault
     with IOMMU before the ctx object is created. At this time,
     fimd_wait_for_vblank() tries to access ctx->crtc but the ctx->crtc
     is still NULL because exynos_drm_crtc_create() isn't called yet.
     This issue is fixed by creating a crtc object and setting it to
     ctx->crtc prior to fimd_wait_for_vblank() call.

     For more details, you can refer to below an e-mail thread,
     http://www.spinics.net/lists/linux-samsung-soc/msg42436.html

   - Remove unnecessary file not used and fix trivial issues.

* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos: fix the initialization order in FIMD
  drm/exynos: fix typo config name correctly.
  drm/exynos: Check for NULL dereference of crtc
  drm/exynos: IS_ERR() vs NULL bug
  drm/exynos: remove unused files
2 parent s 59caeae + cdbfca8
Raw File
interval_tree_test.c
#include <linux/module.h>
#include <linux/interval_tree.h>
#include <linux/random.h>
#include <asm/timex.h>

#define NODES        100
#define PERF_LOOPS   100000
#define SEARCHES     100
#define SEARCH_LOOPS 10000

static struct rb_root root = RB_ROOT;
static struct interval_tree_node nodes[NODES];
static u32 queries[SEARCHES];

static struct rnd_state rnd;

static inline unsigned long
search(unsigned long query, struct rb_root *root)
{
	struct interval_tree_node *node;
	unsigned long results = 0;

	for (node = interval_tree_iter_first(root, query, query); node;
	     node = interval_tree_iter_next(node, query, query))
		results++;
	return results;
}

static void init(void)
{
	int i;
	for (i = 0; i < NODES; i++) {
		u32 a = prandom_u32_state(&rnd);
		u32 b = prandom_u32_state(&rnd);
		if (a <= b) {
			nodes[i].start = a;
			nodes[i].last = b;
		} else {
			nodes[i].start = b;
			nodes[i].last = a;
		}
	}
	for (i = 0; i < SEARCHES; i++)
		queries[i] = prandom_u32_state(&rnd);
}

static int interval_tree_test_init(void)
{
	int i, j;
	unsigned long results;
	cycles_t time1, time2, time;

	printk(KERN_ALERT "interval tree insert/remove");

	prandom_seed_state(&rnd, 3141592653589793238ULL);
	init();

	time1 = get_cycles();

	for (i = 0; i < PERF_LOOPS; i++) {
		for (j = 0; j < NODES; j++)
			interval_tree_insert(nodes + j, &root);
		for (j = 0; j < NODES; j++)
			interval_tree_remove(nodes + j, &root);
	}

	time2 = get_cycles();
	time = time2 - time1;

	time = div_u64(time, PERF_LOOPS);
	printk(" -> %llu cycles\n", (unsigned long long)time);

	printk(KERN_ALERT "interval tree search");

	for (j = 0; j < NODES; j++)
		interval_tree_insert(nodes + j, &root);

	time1 = get_cycles();

	results = 0;
	for (i = 0; i < SEARCH_LOOPS; i++)
		for (j = 0; j < SEARCHES; j++)
			results += search(queries[j], &root);

	time2 = get_cycles();
	time = time2 - time1;

	time = div_u64(time, SEARCH_LOOPS);
	results = div_u64(results, SEARCH_LOOPS);
	printk(" -> %llu cycles (%lu results)\n",
	       (unsigned long long)time, results);

	return -EAGAIN; /* Fail will directly unload the module */
}

static void interval_tree_test_exit(void)
{
	printk(KERN_ALERT "test exit\n");
}

module_init(interval_tree_test_init)
module_exit(interval_tree_test_exit)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michel Lespinasse");
MODULE_DESCRIPTION("Interval Tree test");
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