From 41a9ada3e6b4253f1a3ce42699c6aaeb8584306c Mon Sep 17 00:00:00 2001
From: Reza Arbab <arbab@linux.vnet.ibm.com>
Date: Mon, 12 Dec 2016 16:43:02 -0800
Subject: of/fdt: mark hotpluggable memory

When movable nodes are enabled, any node containing only hotpluggable
memory is made movable at boot time.

On x86, hotpluggable memory is discovered by parsing the ACPI SRAT,
making corresponding calls to memblock_mark_hotplug().

If we introduce a dt property to describe memory as hotpluggable,
configs supporting early fdt may then also do this marking and use
movable nodes.

Link: http://lkml.kernel.org/r/1479160961-25840-5-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alistair Popple <apopple@au1.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/of/fdt.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'drivers/of')

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index c89d5d2..c9b5cac 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1015,6 +1015,7 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 	const __be32 *reg, *endp;
 	int l;
+	bool hotpluggable;
 
 	/* We are scanning "memory" nodes only */
 	if (type == NULL) {
@@ -1034,6 +1035,7 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 		return 0;
 
 	endp = reg + (l / sizeof(__be32));
+	hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
 
 	pr_debug("memory scan node %s, reg size %d,\n", uname, l);
 
@@ -1049,6 +1051,13 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 		    (unsigned long long)size);
 
 		early_init_dt_add_memory_arch(base, size);
+
+		if (!hotpluggable)
+			continue;
+
+		if (early_init_dt_mark_hotplug_memory_arch(base, size))
+			pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
+				base, base + size);
 	}
 
 	return 0;
@@ -1146,6 +1155,11 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 	memblock_add(base, size);
 }
 
+int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
+{
+	return memblock_mark_hotplug(base, size);
+}
+
 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 					phys_addr_t size, bool nomap)
 {
@@ -1168,6 +1182,11 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 	WARN_ON(1);
 }
 
+int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
+{
+	return -ENOSYS;
+}
+
 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 					phys_addr_t size, bool nomap)
 {
-- 
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