svm: driver probe to read l2buff addr

ascend inclusion
category: feature
bugzilla: 16554
CVE: NA

--------

svm probe to read l2buff addr and size, this is rts
to set l2buff
Signed-off-by: Nchenjiankang (A) <chenjiankang1@huawei.com>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: NLi Zefan <lizefan@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/char/svm.c

@@ -1012,6 +1012,30 @@ static const struct file_operations svm_fops = {
 	.open			= svm_open,
 	.unlocked_ioctl		= svm_ioctl,
 };
+
+#ifndef CONFIG_ACPI
+static int svm_setup_l2buff(struct svm_device *sdev, struct device_node *np)
+{
+	struct device_node *l2buff = of_parse_phandle(np, "memory-region", 0);
+
+	if (l2buff) {
+		struct resource r;
+		int err = of_address_to_resource(l2buff, 0, &r);
+
+		if (err) {
+			of_node_put(l2buff);
+			return err;
+		}
+
+		sdev->l2buff = r.start;
+		sdev->l2size = resource_size(&r);
+	}
+
+	of_node_put(l2buff);
+	return 0;
+}
+#endif
+
 /*svm device probe this is init the svm device*/
 static int svm_device_probe(struct platform_device *pdev)
 {
@@ -1066,6 +1090,14 @@ static int svm_device_probe(struct platform_device *pdev)
 #ifdef CONFIG_ACPI
 	err = svm_init_core(sdev);
 #else
+	/*
+	 * Get the l2buff phys address and size, if it do not exist
+	 * just warn and continue, and runtime can not use L2BUFF.
+	 */
+	err = svm_setup_l2buff(sdev, np);
+	if (err)
+		dev_warn(dev, "Cannot get l2buff\n");
+
 	err = svm_init_core(sdev, np);
 #endif