Merge drm/drm-next into drm-intel-next-queued

Some DSI and VBT pending patches from Hans will apply
cleanly and with less ugly conflicts if they are rebuilt
on top of other patches that recently landed on drm-next.

Reference: https://patchwork.freedesktop.org/series/70952/
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com

1 files changed, 194 insertions, 0 deletions

diff --git a/arch/x86/mm/pat/memtype_interval.c b/arch/x86/mm/pat/memtype_interval.c
new file mode 100644
index 000000000000..a07e4882bf36
--- /dev/null
+++ b/arch/x86/mm/pat/memtype_interval.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Handle caching attributes in page tables (PAT)
+ *
+ * Authors: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *          Suresh B Siddha <suresh.b.siddha@intel.com>
+ *
+ * Interval tree used to store the PAT memory type reservations.
+ */
+
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/interval_tree_generic.h>
+#include <linux/sched.h>
+#include <linux/gfp.h>
+
+#include <asm/pgtable.h>
+#include <asm/memtype.h>
+
+#include "memtype.h"
+
+/*
+ * The memtype tree keeps track of memory type for specific
+ * physical memory areas. Without proper tracking, conflicting memory
+ * types in different mappings can cause CPU cache corruption.
+ *
+ * The tree is an interval tree (augmented rbtree) which tree is ordered
+ * by the starting address. The tree can contain multiple entries for
+ * different regions which overlap. All the aliases have the same
+ * cache attributes of course, as enforced by the PAT logic.
+ *
+ * memtype_lock protects the rbtree.
+ */
+
+static inline u64 interval_start(struct memtype *entry)
+{
+	return entry->start;
+}
+
+static inline u64 interval_end(struct memtype *entry)
+{
+	return entry->end - 1;
+}
+
+INTERVAL_TREE_DEFINE(struct memtype, rb, u64, subtree_max_end,
+		     interval_start, interval_end,
+		     static, interval)
+
+static struct rb_root_cached memtype_rbroot = RB_ROOT_CACHED;
+
+enum {
+	MEMTYPE_EXACT_MATCH	= 0,
+	MEMTYPE_END_MATCH	= 1
+};
+
+static struct memtype *memtype_match(u64 start, u64 end, int match_type)
+{
+	struct memtype *entry_match;
+
+	entry_match = interval_iter_first(&memtype_rbroot, start, end-1);
+
+	while (entry_match != NULL && entry_match->start < end) {
+		if ((match_type == MEMTYPE_EXACT_MATCH) &&
+		    (entry_match->start == start) && (entry_match->end == end))
+			return entry_match;
+
+		if ((match_type == MEMTYPE_END_MATCH) &&
+		    (entry_match->start < start) && (entry_match->end == end))
+			return entry_match;
+
+		entry_match = interval_iter_next(entry_match, start, end-1);
+	}
+
+	return NULL; /* Returns NULL if there is no match */
+}
+
+static int memtype_check_conflict(u64 start, u64 end,
+				  enum page_cache_mode reqtype,
+				  enum page_cache_mode *newtype)
+{
+	struct memtype *entry_match;
+	enum page_cache_mode found_type = reqtype;
+
+	entry_match = interval_iter_first(&memtype_rbroot, start, end-1);
+	if (entry_match == NULL)
+		goto success;
+
+	if (entry_match->type != found_type && newtype == NULL)
+		goto failure;
+
+	dprintk("Overlap at 0x%Lx-0x%Lx\n", entry_match->start, entry_match->end);
+	found_type = entry_match->type;
+
+	entry_match = interval_iter_next(entry_match, start, end-1);
+	while (entry_match) {
+		if (entry_match->type != found_type)
+			goto failure;
+
+		entry_match = interval_iter_next(entry_match, start, end-1);
+	}
+success:
+	if (newtype)
+		*newtype = found_type;
+
+	return 0;
+
+failure:
+	pr_info("x86/PAT: %s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
+		current->comm, current->pid, start, end,
+		cattr_name(found_type), cattr_name(entry_match->type));
+
+	return -EBUSY;
+}
+
+int memtype_check_insert(struct memtype *entry_new, enum page_cache_mode *ret_type)
+{
+	int err = 0;
+
+	err = memtype_check_conflict(entry_new->start, entry_new->end, entry_new->type, ret_type);
+	if (err)
+		return err;
+
+	if (ret_type)
+		entry_new->type = *ret_type;
+
+	interval_insert(entry_new, &memtype_rbroot);
+	return 0;
+}
+
+struct memtype *memtype_erase(u64 start, u64 end)
+{
+	struct memtype *entry_old;
+
+	/*
+	 * Since the memtype_rbroot tree allows overlapping ranges,
+	 * memtype_erase() checks with EXACT_MATCH first, i.e. free
+	 * a whole node for the munmap case.  If no such entry is found,
+	 * it then checks with END_MATCH, i.e. shrink the size of a node
+	 * from the end for the mremap case.
+	 */
+	entry_old = memtype_match(start, end, MEMTYPE_EXACT_MATCH);
+	if (!entry_old) {
+		entry_old = memtype_match(start, end, MEMTYPE_END_MATCH);
+		if (!entry_old)
+			return ERR_PTR(-EINVAL);
+	}
+
+	if (entry_old->start == start) {
+		/* munmap: erase this node */
+		interval_remove(entry_old, &memtype_rbroot);
+	} else {
+		/* mremap: update the end value of this node */
+		interval_remove(entry_old, &memtype_rbroot);
+		entry_old->end = start;
+		interval_insert(entry_old, &memtype_rbroot);
+
+		return NULL;
+	}
+
+	return entry_old;
+}
+
+struct memtype *memtype_lookup(u64 addr)
+{
+	return interval_iter_first(&memtype_rbroot, addr, addr + PAGE_SIZE-1);
+}
+
+/*
+ * Debugging helper, copy the Nth entry of the tree into a
+ * a copy for printout. This allows us to print out the tree
+ * via debugfs, without holding the memtype_lock too long:
+ */
+#ifdef CONFIG_DEBUG_FS
+int memtype_copy_nth_element(struct memtype *entry_out, loff_t pos)
+{
+	struct memtype *entry_match;
+	int i = 1;
+
+	entry_match = interval_iter_first(&memtype_rbroot, 0, ULONG_MAX);
+
+	while (entry_match && pos != i) {
+		entry_match = interval_iter_next(entry_match, 0, ULONG_MAX);
+		i++;
+	}
+
+	if (entry_match) { /* pos == i */
+		*entry_out = *entry_match;
+		return 0;
+	} else {
+		return 1;
+	}
+}
+#endif