From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/net/core/xdp.c | 197 ++++++++++++++++++++++++++++++++-----------------
1 files changed, 129 insertions(+), 68 deletions(-)
diff --git a/kernel/net/core/xdp.c b/kernel/net/core/xdp.c
index 89b6785..b8d7fa4 100644
--- a/kernel/net/core/xdp.c
+++ b/kernel/net/core/xdp.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/* net/core/xdp.c
*
* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
- * Released under terms in GPL version 2. See COPYING.
*/
#include <linux/bpf.h>
#include <linux/filter.h>
@@ -11,9 +11,13 @@
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/rhashtable.h>
+#include <linux/bug.h>
#include <net/page_pool.h>
#include <net/xdp.h>
+#include <net/xdp_priv.h> /* struct xdp_mem_allocator */
+#include <trace/events/xdp.h>
+#include <net/xdp_sock_drv.h>
#define REG_STATE_NEW 0x0
#define REG_STATE_REGISTERED 0x1
@@ -29,23 +33,12 @@
static bool mem_id_init; /* false */
static struct rhashtable *mem_id_ht;
-struct xdp_mem_allocator {
- struct xdp_mem_info mem;
- union {
- void *allocator;
- struct page_pool *page_pool;
- struct zero_copy_allocator *zc_alloc;
- };
- struct rhash_head node;
- struct rcu_head rcu;
-};
-
static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
{
const u32 *k = data;
const u32 key = *k;
- BUILD_BUG_ON(FIELD_SIZEOF(struct xdp_mem_allocator, mem.id)
+ BUILD_BUG_ON(sizeof_field(struct xdp_mem_allocator, mem.id)
!= sizeof(u32));
/* Use cyclic increasing ID as direct hash key */
@@ -65,7 +58,7 @@
.nelem_hint = 64,
.head_offset = offsetof(struct xdp_mem_allocator, node),
.key_offset = offsetof(struct xdp_mem_allocator, mem.id),
- .key_len = FIELD_SIZEOF(struct xdp_mem_allocator, mem.id),
+ .key_len = sizeof_field(struct xdp_mem_allocator, mem.id),
.max_size = MEM_ID_MAX,
.min_size = 8,
.automatic_shrinking = true,
@@ -82,34 +75,62 @@
/* Allow this ID to be reused */
ida_simple_remove(&mem_id_pool, xa->mem.id);
- /* Notice, driver is expected to free the *allocator,
- * e.g. page_pool, and MUST also use RCU free.
- */
-
- /* Poison memory */
- xa->mem.id = 0xFFFF;
- xa->mem.type = 0xF0F0;
- xa->allocator = (void *)0xDEAD9001;
-
kfree(xa);
}
-static void __xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
+static void mem_xa_remove(struct xdp_mem_allocator *xa)
+{
+ trace_mem_disconnect(xa);
+
+ if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
+ call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
+}
+
+static void mem_allocator_disconnect(void *allocator)
+{
+ struct xdp_mem_allocator *xa;
+ struct rhashtable_iter iter;
+
+ mutex_lock(&mem_id_lock);
+
+ rhashtable_walk_enter(mem_id_ht, &iter);
+ do {
+ rhashtable_walk_start(&iter);
+
+ while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) {
+ if (xa->allocator == allocator)
+ mem_xa_remove(xa);
+ }
+
+ rhashtable_walk_stop(&iter);
+
+ } while (xa == ERR_PTR(-EAGAIN));
+ rhashtable_walk_exit(&iter);
+
+ mutex_unlock(&mem_id_lock);
+}
+
+void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
{
struct xdp_mem_allocator *xa;
int id = xdp_rxq->mem.id;
+ if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
+ WARN(1, "Missing register, driver bug");
+ return;
+ }
+
if (id == 0)
return;
- mutex_lock(&mem_id_lock);
-
- xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params);
- if (xa && !rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
- call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
-
- mutex_unlock(&mem_id_lock);
+ if (xdp_rxq->mem.type == MEM_TYPE_PAGE_POOL) {
+ rcu_read_lock();
+ xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params);
+ page_pool_destroy(xa->page_pool);
+ rcu_read_unlock();
+ }
}
+EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model);
void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
{
@@ -119,7 +140,7 @@
WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG");
- __xdp_rxq_info_unreg_mem_model(xdp_rxq);
+ xdp_rxq_info_unreg_mem_model(xdp_rxq);
xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
xdp_rxq->dev = NULL;
@@ -257,7 +278,7 @@
xdp_rxq->mem.type = type;
if (!allocator) {
- if (type == MEM_TYPE_PAGE_POOL || type == MEM_TYPE_ZERO_COPY)
+ if (type == MEM_TYPE_PAGE_POOL)
return -EINVAL; /* Setup time check page_pool req */
return 0;
}
@@ -290,12 +311,18 @@
/* Insert allocator into ID lookup table */
ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
if (IS_ERR(ptr)) {
+ ida_simple_remove(&mem_id_pool, xdp_rxq->mem.id);
+ xdp_rxq->mem.id = 0;
errno = PTR_ERR(ptr);
goto err;
}
+ if (type == MEM_TYPE_PAGE_POOL)
+ page_pool_use_xdp_mem(allocator, mem_allocator_disconnect);
+
mutex_unlock(&mem_id_lock);
+ trace_mem_connect(xdp_alloc, xdp_rxq);
return 0;
err:
mutex_unlock(&mem_id_lock);
@@ -306,12 +333,12 @@
/* XDP RX runs under NAPI protection, and in different delivery error
* scenarios (e.g. queue full), it is possible to return the xdp_frame
- * while still leveraging this protection. The @napi_direct boolian
+ * while still leveraging this protection. The @napi_direct boolean
* is used for those calls sites. Thus, allowing for faster recycling
* of xdp_frames/pages in those cases.
*/
static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
- unsigned long handle)
+ struct xdp_buff *xdp)
{
struct xdp_mem_allocator *xa;
struct page *page;
@@ -322,12 +349,9 @@
/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
page = virt_to_head_page(data);
- if (xa) {
- napi_direct &= !xdp_return_frame_no_direct();
- page_pool_put_page(xa->page_pool, page, napi_direct);
- } else {
- put_page(page);
- }
+ if (napi_direct && xdp_return_frame_no_direct())
+ napi_direct = false;
+ page_pool_put_full_page(xa->page_pool, page, napi_direct);
rcu_read_unlock();
break;
case MEM_TYPE_PAGE_SHARED:
@@ -337,57 +361,48 @@
page = virt_to_page(data); /* Assumes order0 page*/
put_page(page);
break;
- case MEM_TYPE_ZERO_COPY:
+ case MEM_TYPE_XSK_BUFF_POOL:
/* NB! Only valid from an xdp_buff! */
- rcu_read_lock();
- /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
- xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
- xa->zc_alloc->free(xa->zc_alloc, handle);
- rcu_read_unlock();
+ xsk_buff_free(xdp);
+ break;
default:
/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
+ WARN(1, "Incorrect XDP memory type (%d) usage", mem->type);
break;
}
}
void xdp_return_frame(struct xdp_frame *xdpf)
{
- __xdp_return(xdpf->data, &xdpf->mem, false, 0);
+ __xdp_return(xdpf->data, &xdpf->mem, false, NULL);
}
EXPORT_SYMBOL_GPL(xdp_return_frame);
void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
{
- __xdp_return(xdpf->data, &xdpf->mem, true, 0);
+ __xdp_return(xdpf->data, &xdpf->mem, true, NULL);
}
EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
void xdp_return_buff(struct xdp_buff *xdp)
{
- __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle);
+ __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp);
}
-EXPORT_SYMBOL_GPL(xdp_return_buff);
-int xdp_attachment_query(struct xdp_attachment_info *info,
- struct netdev_bpf *bpf)
+/* Only called for MEM_TYPE_PAGE_POOL see xdp.h */
+void __xdp_release_frame(void *data, struct xdp_mem_info *mem)
{
- bpf->prog_id = info->prog ? info->prog->aux->id : 0;
- bpf->prog_flags = info->prog ? info->flags : 0;
- return 0;
-}
-EXPORT_SYMBOL_GPL(xdp_attachment_query);
+ struct xdp_mem_allocator *xa;
+ struct page *page;
-bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
- struct netdev_bpf *bpf)
-{
- if (info->prog && (bpf->flags ^ info->flags) & XDP_FLAGS_MODES) {
- NL_SET_ERR_MSG(bpf->extack,
- "program loaded with different flags");
- return false;
- }
- return true;
+ rcu_read_lock();
+ xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
+ page = virt_to_head_page(data);
+ if (xa)
+ page_pool_release_page(xa->page_pool, page);
+ rcu_read_unlock();
}
-EXPORT_SYMBOL_GPL(xdp_attachment_flags_ok);
+EXPORT_SYMBOL_GPL(__xdp_release_frame);
void xdp_attachment_setup(struct xdp_attachment_info *info,
struct netdev_bpf *bpf)
@@ -398,3 +413,49 @@
info->flags = bpf->flags;
}
EXPORT_SYMBOL_GPL(xdp_attachment_setup);
+
+struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp)
+{
+ unsigned int metasize, totsize;
+ void *addr, *data_to_copy;
+ struct xdp_frame *xdpf;
+ struct page *page;
+
+ /* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */
+ metasize = xdp_data_meta_unsupported(xdp) ? 0 :
+ xdp->data - xdp->data_meta;
+ totsize = xdp->data_end - xdp->data + metasize;
+
+ if (sizeof(*xdpf) + totsize > PAGE_SIZE)
+ return NULL;
+
+ page = dev_alloc_page();
+ if (!page)
+ return NULL;
+
+ addr = page_to_virt(page);
+ xdpf = addr;
+ memset(xdpf, 0, sizeof(*xdpf));
+
+ addr += sizeof(*xdpf);
+ data_to_copy = metasize ? xdp->data_meta : xdp->data;
+ memcpy(addr, data_to_copy, totsize);
+
+ xdpf->data = addr + metasize;
+ xdpf->len = totsize - metasize;
+ xdpf->headroom = 0;
+ xdpf->metasize = metasize;
+ xdpf->frame_sz = PAGE_SIZE;
+ xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
+
+ xsk_buff_free(xdp);
+ return xdpf;
+}
+EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);
+
+/* Used by XDP_WARN macro, to avoid inlining WARN() in fast-path */
+void xdp_warn(const char *msg, const char *func, const int line)
+{
+ WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg);
+};
+EXPORT_SYMBOL_GPL(xdp_warn);
--
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