--- zzzz-none-000/linux-3.10.107/arch/sparc/kernel/mdesc.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/sparc/kernel/mdesc.c	2021-02-04 17:41:59.000000000 +0000
@@ -130,26 +130,26 @@
 static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size)
 {
 	unsigned int handle_size;
+	struct mdesc_handle *hp;
+	unsigned long addr;
 	void *base;
 
 	handle_size = (sizeof(struct mdesc_handle) -
 		       sizeof(struct mdesc_hdr) +
 		       mdesc_size);
 
+	/*
+	 * Allocation has to succeed because mdesc update would be missed
+	 * and such events are not retransmitted.
+	 */
 	base = kmalloc(handle_size + 15, GFP_KERNEL | __GFP_NOFAIL);
-	if (base) {
-		struct mdesc_handle *hp;
-		unsigned long addr;
-
-		addr = (unsigned long)base;
-		addr = (addr + 15UL) & ~15UL;
-		hp = (struct mdesc_handle *) addr;
+	addr = (unsigned long)base;
+	addr = (addr + 15UL) & ~15UL;
+	hp = (struct mdesc_handle *) addr;
 
-		mdesc_handle_init(hp, handle_size, base);
-		return hp;
-	}
+	mdesc_handle_init(hp, handle_size, base);
 
-	return NULL;
+	return hp;
 }
 
 static void mdesc_kfree(struct mdesc_handle *hp)
@@ -571,9 +571,7 @@
 	mdesc_release(hp);
 }
 
-static void __cpuinit fill_in_one_cache(cpuinfo_sparc *c,
-					struct mdesc_handle *hp,
-					u64 mp)
+static void fill_in_one_cache(cpuinfo_sparc *c, struct mdesc_handle *hp, u64 mp)
 {
 	const u64 *level = mdesc_get_property(hp, mp, "level", NULL);
 	const u64 *size = mdesc_get_property(hp, mp, "size", NULL);
@@ -616,45 +614,68 @@
 	}
 }
 
-static void __cpuinit mark_core_ids(struct mdesc_handle *hp, u64 mp, int core_id)
+static void find_back_node_value(struct mdesc_handle *hp, u64 node,
+				 char *srch_val,
+				 void (*func)(struct mdesc_handle *, u64, int),
+				 u64 val, int depth)
 {
-	u64 a;
+	u64 arc;
 
-	mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_BACK) {
-		u64 t = mdesc_arc_target(hp, a);
-		const char *name;
-		const u64 *id;
-
-		name = mdesc_node_name(hp, t);
-		if (!strcmp(name, "cpu")) {
-			id = mdesc_get_property(hp, t, "id", NULL);
-			if (*id < NR_CPUS)
-				cpu_data(*id).core_id = core_id;
-		} else {
-			u64 j;
+	/* Since we have an estimate of recursion depth, do a sanity check. */
+	if (depth == 0)
+		return;
 
-			mdesc_for_each_arc(j, hp, t, MDESC_ARC_TYPE_BACK) {
-				u64 n = mdesc_arc_target(hp, j);
-				const char *n_name;
+	mdesc_for_each_arc(arc, hp, node, MDESC_ARC_TYPE_BACK) {
+		u64 n = mdesc_arc_target(hp, arc);
+		const char *name = mdesc_node_name(hp, n);
 
-				n_name = mdesc_node_name(hp, n);
-				if (strcmp(n_name, "cpu"))
-					continue;
+		if (!strcmp(srch_val, name))
+			(*func)(hp, n, val);
 
-				id = mdesc_get_property(hp, n, "id", NULL);
-				if (*id < NR_CPUS)
-					cpu_data(*id).core_id = core_id;
-			}
-		}
+		find_back_node_value(hp, n, srch_val, func, val, depth-1);
 	}
 }
 
-static void __cpuinit set_core_ids(struct mdesc_handle *hp)
+static void __mark_core_id(struct mdesc_handle *hp, u64 node,
+			   int core_id)
+{
+	const u64 *id = mdesc_get_property(hp, node, "id", NULL);
+
+	if (*id < num_possible_cpus())
+		cpu_data(*id).core_id = core_id;
+}
+
+static void __mark_sock_id(struct mdesc_handle *hp, u64 node,
+			   int sock_id)
+{
+	const u64 *id = mdesc_get_property(hp, node, "id", NULL);
+
+	if (*id < num_possible_cpus())
+		cpu_data(*id).sock_id = sock_id;
+}
+
+static void mark_core_ids(struct mdesc_handle *hp, u64 mp,
+			  int core_id)
+{
+	find_back_node_value(hp, mp, "cpu", __mark_core_id, core_id, 10);
+}
+
+static void mark_sock_ids(struct mdesc_handle *hp, u64 mp,
+			  int sock_id)
+{
+	find_back_node_value(hp, mp, "cpu", __mark_sock_id, sock_id, 10);
+}
+
+static void set_core_ids(struct mdesc_handle *hp)
 {
 	int idx;
 	u64 mp;
 
 	idx = 1;
+
+	/* Identify unique cores by looking for cpus backpointed to by
+	 * level 1 instruction caches.
+	 */
 	mdesc_for_each_node_by_name(hp, mp, "cache") {
 		const u64 *level;
 		const char *type;
@@ -669,12 +690,73 @@
 			continue;
 
 		mark_core_ids(hp, mp, idx);
+		idx++;
+	}
+}
+
+static int set_sock_ids_by_cache(struct mdesc_handle *hp, int level)
+{
+	u64 mp;
+	int idx = 1;
+	int fnd = 0;
 
+	/* Identify unique sockets by looking for cpus backpointed to by
+	 * shared level n caches.
+	 */
+	mdesc_for_each_node_by_name(hp, mp, "cache") {
+		const u64 *cur_lvl;
+
+		cur_lvl = mdesc_get_property(hp, mp, "level", NULL);
+		if (*cur_lvl != level)
+			continue;
+
+		mark_sock_ids(hp, mp, idx);
 		idx++;
+		fnd = 1;
 	}
+	return fnd;
 }
 
-static void __cpuinit mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
+static void set_sock_ids_by_socket(struct mdesc_handle *hp, u64 mp)
+{
+	int idx = 1;
+
+	mdesc_for_each_node_by_name(hp, mp, "socket") {
+		u64 a;
+
+		mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
+			u64 t = mdesc_arc_target(hp, a);
+			const char *name;
+			const u64 *id;
+
+			name = mdesc_node_name(hp, t);
+			if (strcmp(name, "cpu"))
+				continue;
+
+			id = mdesc_get_property(hp, t, "id", NULL);
+			if (*id < num_possible_cpus())
+				cpu_data(*id).sock_id = idx;
+		}
+		idx++;
+	}
+}
+
+static void set_sock_ids(struct mdesc_handle *hp)
+{
+	u64 mp;
+
+	/* If machine description exposes sockets data use it.
+	 * Otherwise fallback to use shared L3 or L2 caches.
+	 */
+	mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "sockets");
+	if (mp != MDESC_NODE_NULL)
+		return set_sock_ids_by_socket(hp, mp);
+
+	if (!set_sock_ids_by_cache(hp, 3))
+		set_sock_ids_by_cache(hp, 2);
+}
+
+static void mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
 {
 	u64 a;
 
@@ -693,7 +775,7 @@
 	}
 }
 
-static void __cpuinit __set_proc_ids(struct mdesc_handle *hp, const char *exec_unit_name)
+static void __set_proc_ids(struct mdesc_handle *hp, const char *exec_unit_name)
 {
 	int idx;
 	u64 mp;
@@ -709,19 +791,18 @@
 			continue;
 
 		mark_proc_ids(hp, mp, idx);
-
 		idx++;
 	}
 }
 
-static void __cpuinit set_proc_ids(struct mdesc_handle *hp)
+static void set_proc_ids(struct mdesc_handle *hp)
 {
 	__set_proc_ids(hp, "exec_unit");
 	__set_proc_ids(hp, "exec-unit");
 }
 
-static void __cpuinit get_one_mondo_bits(const u64 *p, unsigned int *mask,
-					 unsigned long def, unsigned long max)
+static void get_one_mondo_bits(const u64 *p, unsigned int *mask,
+			       unsigned long def, unsigned long max)
 {
 	u64 val;
 
@@ -742,8 +823,8 @@
 	*mask = ((1U << def) * 64U) - 1U;
 }
 
-static void __cpuinit get_mondo_data(struct mdesc_handle *hp, u64 mp,
-				     struct trap_per_cpu *tb)
+static void get_mondo_data(struct mdesc_handle *hp, u64 mp,
+			   struct trap_per_cpu *tb)
 {
 	static int printed;
 	const u64 *val;
@@ -769,7 +850,7 @@
 	}
 }
 
-static void * __cpuinit mdesc_iterate_over_cpus(void *(*func)(struct mdesc_handle *, u64, int, void *), void *arg, cpumask_t *mask)
+static void *mdesc_iterate_over_cpus(void *(*func)(struct mdesc_handle *, u64, int, void *), void *arg, cpumask_t *mask)
 {
 	struct mdesc_handle *hp = mdesc_grab();
 	void *ret = NULL;
@@ -799,7 +880,8 @@
 	return ret;
 }
 
-static void * __cpuinit record_one_cpu(struct mdesc_handle *hp, u64 mp, int cpuid, void *arg)
+static void *record_one_cpu(struct mdesc_handle *hp, u64 mp, int cpuid,
+			    void *arg)
 {
 	ncpus_probed++;
 #ifdef CONFIG_SMP
@@ -808,7 +890,7 @@
 	return NULL;
 }
 
-void __cpuinit mdesc_populate_present_mask(cpumask_t *mask)
+void mdesc_populate_present_mask(cpumask_t *mask)
 {
 	if (tlb_type != hypervisor)
 		return;
@@ -841,7 +923,8 @@
 	mdesc_iterate_over_cpus(check_one_pgsz, pgsz_mask, mask);
 }
 
-static void * __cpuinit fill_in_one_cpu(struct mdesc_handle *hp, u64 mp, int cpuid, void *arg)
+static void *fill_in_one_cpu(struct mdesc_handle *hp, u64 mp, int cpuid,
+			     void *arg)
 {
 	const u64 *cfreq = mdesc_get_property(hp, mp, "clock-frequency", NULL);
 	struct trap_per_cpu *tb;
@@ -890,49 +973,102 @@
 	return NULL;
 }
 
-void __cpuinit mdesc_fill_in_cpu_data(cpumask_t *mask)
+void mdesc_fill_in_cpu_data(cpumask_t *mask)
 {
 	struct mdesc_handle *hp;
 
 	mdesc_iterate_over_cpus(fill_in_one_cpu, NULL, mask);
 
-#ifdef CONFIG_SMP
-	sparc64_multi_core = 1;
-#endif
-
 	hp = mdesc_grab();
 
 	set_core_ids(hp);
 	set_proc_ids(hp);
+	set_sock_ids(hp);
 
 	mdesc_release(hp);
 
 	smp_fill_in_sib_core_maps();
 }
 
-static ssize_t mdesc_read(struct file *file, char __user *buf,
-			  size_t len, loff_t *offp)
+/* mdesc_open() - Grab a reference to mdesc_handle when /dev/mdesc is
+ * opened. Hold this reference until /dev/mdesc is closed to ensure
+ * mdesc data structure is not released underneath us. Store the
+ * pointer to mdesc structure in private_data for read and seek to use
+ */
+static int mdesc_open(struct inode *inode, struct file *file)
 {
 	struct mdesc_handle *hp = mdesc_grab();
-	int err;
 
 	if (!hp)
 		return -ENODEV;
 
-	err = hp->handle_size;
-	if (len < hp->handle_size)
-		err = -EMSGSIZE;
-	else if (copy_to_user(buf, &hp->mdesc, hp->handle_size))
-		err = -EFAULT;
-	mdesc_release(hp);
+	file->private_data = hp;
+
+	return 0;
+}
+
+static ssize_t mdesc_read(struct file *file, char __user *buf,
+			  size_t len, loff_t *offp)
+{
+	struct mdesc_handle *hp = file->private_data;
+	unsigned char *mdesc;
+	int bytes_left, count = len;
+
+	if (*offp >= hp->handle_size)
+		return 0;
+
+	bytes_left = hp->handle_size - *offp;
+	if (count > bytes_left)
+		count = bytes_left;
+
+	mdesc = (unsigned char *)&hp->mdesc;
+	mdesc += *offp;
+	if (!copy_to_user(buf, mdesc, count)) {
+		*offp += count;
+		return count;
+	} else {
+		return -EFAULT;
+	}
+}
 
-	return err;
+static loff_t mdesc_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct mdesc_handle *hp;
+
+	switch (whence) {
+	case SEEK_CUR:
+		offset += file->f_pos;
+		break;
+	case SEEK_SET:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	hp = file->private_data;
+	if (offset > hp->handle_size)
+		return -EINVAL;
+	else
+		file->f_pos = offset;
+
+	return offset;
+}
+
+/* mdesc_close() - /dev/mdesc is being closed, release the reference to
+ * mdesc structure.
+ */
+static int mdesc_close(struct inode *inode, struct file *file)
+{
+	mdesc_release(file->private_data);
+	return 0;
 }
 
 static const struct file_operations mdesc_fops = {
-	.read	= mdesc_read,
-	.owner	= THIS_MODULE,
-	.llseek = noop_llseek,
+	.open    = mdesc_open,
+	.read	 = mdesc_read,
+	.llseek  = mdesc_llseek,
+	.release = mdesc_close,
+	.owner	 = THIS_MODULE,
 };
 
 static struct miscdevice mdesc_misc = {