From: Jonathan Lemon <jonathan.lemon@gmail.com>
To: <netdev@vger.kernel.org>
Cc: <kernel-team@fb.com>
Subject: [RFC PATCH v2 02/21] mm/memory_hotplug: add {add|release}_memory_pages
Date: Mon, 27 Jul 2020 15:44:25 -0700 [thread overview]
Message-ID: <20200727224444.2987641-3-jonathan.lemon@gmail.com> (raw)
In-Reply-To: <20200727224444.2987641-1-jonathan.lemon@gmail.com>
These calls allows creation of system pages at a specific physical
address, which is useful for creating dummy backing pages which
correspond to unaddressable external memory at specific locations.
__add_memory_pages() adds the requested page range to /proc/iomem and
verifies that there are no overlaps. Once this succeeds, then the page
section is initialized, which may overlap with a prior request, since
section sizes are large, so ignore the latter overlap.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
---
include/linux/memory_hotplug.h | 4 +++
mm/memory_hotplug.c | 65 ++++++++++++++++++++++++++++++++--
2 files changed, 67 insertions(+), 2 deletions(-)
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 375515803cd8..05e012e1a203 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -138,6 +138,10 @@ extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
struct mhp_params *params);
+struct resource *add_memory_pages(int nid, u64 start, u64 size,
+ struct mhp_params *params);
+void release_memory_pages(struct resource *res);
+
#ifndef CONFIG_ARCH_HAS_ADD_PAGES
static inline int add_pages(int nid, unsigned long start_pfn,
unsigned long nr_pages, struct mhp_params *params)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index da374cd3d45b..c1a923189869 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -125,8 +125,8 @@ static struct resource *register_memory_resource(u64 start, u64 size,
resource_name, flags);
if (!res) {
- pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n",
- start, start + size);
+ pr_debug("Unable to reserve %s region: %016llx->%016llx\n",
+ resource_name, start, start + size);
return ERR_PTR(-EEXIST);
}
return res;
@@ -1118,6 +1118,67 @@ int add_memory(int nid, u64 start, u64 size)
}
EXPORT_SYMBOL_GPL(add_memory);
+static int __ref add_memory_section(int nid, struct resource *res,
+ struct mhp_params *params)
+{
+ u64 start, end, section_size;
+ int ret;
+
+ /* must align start/end with memory block size */
+ end = res->start + resource_size(res);
+ section_size = memory_block_size_bytes();
+ start = round_down(res->start, section_size);
+ end = round_up(end, section_size);
+
+ mem_hotplug_begin();
+ ret = __add_pages(nid,
+ PHYS_PFN(start), PHYS_PFN(end - start), params);
+ mem_hotplug_done();
+
+ return ret;
+}
+
+/* requires device_hotplug_lock, see add_memory_resource() */
+static struct resource * __ref __add_memory_pages(int nid, u64 start, u64 size,
+ struct mhp_params *params)
+{
+ struct resource *res;
+ int ret;
+
+ res = register_memory_resource(start, size, "Private RAM");
+ if (IS_ERR(res))
+ return res;
+
+ ret = add_memory_section(nid, res, params);
+ if (ret < 0 && ret != -EEXIST) {
+ release_memory_resource(res);
+ return ERR_PTR(ret);
+ }
+
+ return res;
+}
+
+struct resource *add_memory_pages(int nid, u64 start, u64 size,
+ struct mhp_params *params)
+{
+ struct resource *res;
+
+ lock_device_hotplug();
+ res = __add_memory_pages(nid, start, size, params);
+ unlock_device_hotplug();
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(add_memory_pages);
+
+void release_memory_pages(struct resource *res)
+{
+ lock_device_hotplug();
+ release_memory_resource(res);
+ unlock_device_hotplug();
+}
+EXPORT_SYMBOL_GPL(release_memory_pages);
+
/*
* Add special, driver-managed memory to the system as system RAM. Such
* memory is not exposed via the raw firmware-provided memmap as system
--
2.24.1
next prev parent reply other threads:[~2020-07-27 22:44 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 22:44 [RFC PATCH v2 00/21] netgpu: networking between NIC and GPU/CPU Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 01/21] linux/log2.h: enclose macro arg in parens Jonathan Lemon
2020-07-27 22:44 ` Jonathan Lemon [this message]
2020-07-27 22:44 ` [RFC PATCH v2 03/21] mm: Allow DMA mapping of pages which are not online Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 04/21] kernel/user: export free_uid Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 05/21] uapi/misc: add shqueue.h for shared queues Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 06/21] include: add netgpu UAPI and kernel definitions Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 07/21] netdevice: add SETUP_NETGPU to the netdev_bpf structure Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 08/21] skbuff: add a zc_netgpu bitflag Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 09/21] core/skbuff: use skb_zdata for testing whether skb is zerocopy Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 10/21] netgpu: add network/gpu/host dma module Jonathan Lemon
2020-07-28 16:26 ` Greg KH
2020-07-28 17:41 ` Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 11/21] core/skbuff: add page recycling logic for netgpu pages Jonathan Lemon
2020-07-28 16:28 ` Greg KH
2020-07-28 18:00 ` Jonathan Lemon
2020-07-28 18:26 ` Greg KH
2020-07-27 22:44 ` [RFC PATCH v2 12/21] lib: have __zerocopy_sg_from_iter get netgpu pages for a sk Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 13/21] net/tcp: Pad TCP options out to a fixed size for netgpu Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 14/21] net/tcp: add netgpu ioctl setting up zero copy RX queues Jonathan Lemon
2020-07-28 2:16 ` Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 15/21] net/tcp: add MSG_NETDMA flag for sendmsg() Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 16/21] mlx5: remove the umem parameter from mlx5e_open_channel Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 17/21] mlx5e: add header split ability Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 18/21] mlx5e: add netgpu entries to mlx5 structures Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 19/21] mlx5e: add the netgpu driver functions Jonathan Lemon
2020-07-28 16:27 ` Greg KH
2020-07-27 22:44 ` [RFC PATCH v2 20/21] mlx5e: hook up the netgpu functions Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 21/21] netgpu/nvidia: add Nvidia plugin for netgpu Jonathan Lemon
2020-07-28 16:31 ` Greg KH
2020-07-28 17:18 ` Chris Mason
2020-07-28 17:27 ` Christoph Hellwig
2020-07-28 18:47 ` Chris Mason
2020-07-28 19:55 ` [RFC PATCH v2 00/21] netgpu: networking between NIC and GPU/CPU Stephen Hemminger
2020-07-28 20:43 ` Jonathan Lemon
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