[PATCH v3 3/7] mm/memory_hotplug: prepare passing flags to add_memory() and friends

[David Hildenbrand <david@xxxxxxxxxx>]

We soon want to pass flags, e.g., to mark added System RAM resources.
mergeable. Prepare for that.

This patch is based on a similar patch by Oscar Salvador:

https://lkml.kernel.org/r/20190625075227.15193-3-osalvador@xxxxxxx

Acked-by: Wei Liu <wei.liu@xxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx> # Xen related part
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: Wei Liu <wei.liu@xxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: "Oliver O'Halloran" <oohall@xxxxxxxxx>
Cc: Pingfan Liu <kernelfans@xxxxxxxxx>
Cc: Nathan Lynch <nathanl@xxxxxxxxxxxxx>
Cc: Libor Pechacek <lpechacek@xxxxxxx>
Cc: Anton Blanchard <anton@xxxxxxxxxx>
Cc: Leonardo Bras <leobras.c@xxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-nvdimm@xxxxxxxxxxxx
Cc: linux-hyperv@xxxxxxxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 arch/powerpc/platforms/powernv/memtrace.c       |  2 +-
 arch/powerpc/platforms/pseries/hotplug-memory.c |  2 +-
 drivers/acpi/acpi_memhotplug.c                  |  3 ++-
 drivers/base/memory.c                           |  3 ++-
 drivers/dax/kmem.c                              |  2 +-
 drivers/hv/hv_balloon.c                         |  2 +-
 drivers/s390/char/sclp_cmd.c                    |  2 +-
 drivers/virtio/virtio_mem.c                     |  2 +-
 drivers/xen/balloon.c                           |  2 +-
 include/linux/memory_hotplug.h                  | 16 ++++++++++++----
 mm/memory_hotplug.c                             | 14 +++++++-------
 11 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/memtrace.c 
b/arch/powerpc/platforms/powernv/memtrace.c
index 13b369d2cc454..6828108486f83 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -224,7 +224,7 @@ static int memtrace_online(void)
                        ent->mem = 0;
                }
 
-               if (add_memory(ent->nid, ent->start, ent->size)) {
+               if (add_memory(ent->nid, ent->start, ent->size, MHP_NONE)) {
                        pr_err("Failed to add trace memory to node %d\n",
                                ent->nid);
                        ret += 1;
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c 
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 0ea976d1cac47..e1c9fa0d730f5 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -615,7 +615,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
        nid = memory_add_physaddr_to_nid(lmb->base_addr);
 
        /* Add the memory */
-       rc = __add_memory(nid, lmb->base_addr, block_sz);
+       rc = __add_memory(nid, lmb->base_addr, block_sz, MHP_NONE);
        if (rc) {
                invalidate_lmb_associativity_index(lmb);
                return rc;
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e294f44a78504..2067c3bc55763 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -207,7 +207,8 @@ static int acpi_memory_enable_device(struct 
acpi_memory_device *mem_device)
                if (node < 0)
                        node = memory_add_physaddr_to_nid(info->start_addr);
 
-               result = __add_memory(node, info->start_addr, info->length);
+               result = __add_memory(node, info->start_addr, info->length,
+                                     MHP_NONE);
 
                /*
                 * If the memory block has been used by the kernel, add_memory()
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 4db3c660de831..b4c297dd04755 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -432,7 +432,8 @@ static ssize_t probe_store(struct device *dev, struct 
device_attribute *attr,
 
        nid = memory_add_physaddr_to_nid(phys_addr);
        ret = __add_memory(nid, phys_addr,
-                          MIN_MEMORY_BLOCK_SIZE * sections_per_block);
+                          MIN_MEMORY_BLOCK_SIZE * sections_per_block,
+                          MHP_NONE);
 
        if (ret)
                goto out;
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 7dcb2902e9b1b..896cb9444e727 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -95,7 +95,7 @@ int dev_dax_kmem_probe(struct dev_dax *dev_dax)
                 * this as RAM automatically.
                 */
                rc = add_memory_driver_managed(numa_node, range.start,
-                               range_len(&range), kmem_name);
+                               range_len(&range), kmem_name, MHP_NONE);
 
                res->flags |= IORESOURCE_BUSY;
                if (rc) {
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 32e3bc0aa665a..3c0d52e244520 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -726,7 +726,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned 
long size,
 
                nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
                ret = add_memory(nid, PFN_PHYS((start_pfn)),
-                               (HA_CHUNK << PAGE_SHIFT));
+                               (HA_CHUNK << PAGE_SHIFT), MHP_NONE);
 
                if (ret) {
                        pr_err("hot_add memory failed error is %d\n", ret);
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index a864b21af602a..f6e97f0830f64 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -406,7 +406,7 @@ static void __init add_memory_merged(u16 rn)
        if (!size)
                goto skip_add;
        for (addr = start; addr < start + size; addr += block_size)
-               add_memory(0, addr, block_size);
+               add_memory(0, addr, block_size, MHP_NONE);
 skip_add:
        first_rn = rn;
        num = 1;
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 834b7c13ef3dc..ed99e43354010 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -424,7 +424,7 @@ static int virtio_mem_mb_add(struct virtio_mem *vm, 
unsigned long mb_id)
 
        dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id);
        return add_memory_driver_managed(nid, addr, memory_block_size_bytes(),
-                                        vm->resource_name);
+                                        vm->resource_name, MHP_NONE);
 }
 
 /*
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 51427c752b37b..9f40a294d398d 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -331,7 +331,7 @@ static enum bp_state reserve_additional_memory(void)
        mutex_unlock(&balloon_mutex);
        /* add_memory_resource() requires the device_hotplug lock */
        lock_device_hotplug();
-       rc = add_memory_resource(nid, resource);
+       rc = add_memory_resource(nid, resource, MHP_NONE);
        unlock_device_hotplug();
        mutex_lock(&balloon_mutex);
 
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 51a877fec8da8..e53d1058f3443 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -57,6 +57,12 @@ enum {
        MMOP_ONLINE_MOVABLE,
 };
 
+/* Flags for add_memory() and friends to specify memory hotplug details. */
+typedef int __bitwise mhp_t;
+
+/* No special request */
+#define MHP_NONE               ((__force mhp_t)0)
+
 /*
  * Extended parameters for memory hotplug:
  * altmap: alternative allocator for memmap array (optional)
@@ -345,11 +351,13 @@ extern void set_zone_contiguous(struct zone *zone);
 extern void clear_zone_contiguous(struct zone *zone);
 
 extern void __ref free_area_init_core_hotplug(int nid);
-extern int __add_memory(int nid, u64 start, u64 size);
-extern int add_memory(int nid, u64 start, u64 size);
-extern int add_memory_resource(int nid, struct resource *resource);
+extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
+extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);
+extern int add_memory_resource(int nid, struct resource *resource,
+                              mhp_t mhp_flags);
 extern int add_memory_driver_managed(int nid, u64 start, u64 size,
-                                    const char *resource_name);
+                                    const char *resource_name,
+                                    mhp_t mhp_flags);
 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
                                   unsigned long nr_pages,
                                   struct vmem_altmap *altmap, int migratetype);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8e1cd18b5cf14..8f0bd7c9a63a5 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1039,7 +1039,7 @@ static int online_memory_block(struct memory_block *mem, 
void *arg)
  *
  * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
  */
-int __ref add_memory_resource(int nid, struct resource *res)
+int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 {
        struct mhp_params params = { .pgprot = PAGE_KERNEL };
        u64 start, size;
@@ -1118,7 +1118,7 @@ int __ref add_memory_resource(int nid, struct resource 
*res)
 }
 
 /* requires device_hotplug_lock, see add_memory_resource() */
-int __ref __add_memory(int nid, u64 start, u64 size)
+int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags)
 {
        struct resource *res;
        int ret;
@@ -1127,18 +1127,18 @@ int __ref __add_memory(int nid, u64 start, u64 size)
        if (IS_ERR(res))
                return PTR_ERR(res);
 
-       ret = add_memory_resource(nid, res);
+       ret = add_memory_resource(nid, res, mhp_flags);
        if (ret < 0)
                release_memory_resource(res);
        return ret;
 }
 
-int add_memory(int nid, u64 start, u64 size)
+int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags)
 {
        int rc;
 
        lock_device_hotplug();
-       rc = __add_memory(nid, start, size);
+       rc = __add_memory(nid, start, size, mhp_flags);
        unlock_device_hotplug();
 
        return rc;
@@ -1167,7 +1167,7 @@ EXPORT_SYMBOL_GPL(add_memory);
  * "System RAM ($DRIVER)".
  */
 int add_memory_driver_managed(int nid, u64 start, u64 size,
-                             const char *resource_name)
+                             const char *resource_name, mhp_t mhp_flags)
 {
        struct resource *res;
        int rc;
@@ -1185,7 +1185,7 @@ int add_memory_driver_managed(int nid, u64 start, u64 
size,
                goto out_unlock;
        }
 
-       rc = add_memory_resource(nid, res);
+       rc = add_memory_resource(nid, res, mhp_flags);
        if (rc < 0)
                release_memory_resource(res);
 
-- 
2.26.2