From f9004dbfff8a3fbbd7e2a88c8a4327c7f2f8e5b2 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 01:04:47 +0000
Subject: [PATCH] add driver 5G
---
kernel/include/linux/bvec.h | 146 +++++++++++++++++++++++++++++-------------------
1 files changed, 89 insertions(+), 57 deletions(-)
diff --git a/kernel/include/linux/bvec.h b/kernel/include/linux/bvec.h
index bc1f16e..2efec10 100644
--- a/kernel/include/linux/bvec.h
+++ b/kernel/include/linux/bvec.h
@@ -1,31 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
/*
* bvec iterator
*
* Copyright (C) 2001 Ming Lei <ming.lei@canonical.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public Licens
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
*/
#ifndef __LINUX_BVEC_ITER_H
#define __LINUX_BVEC_ITER_H
-#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/errno.h>
+#include <linux/limits.h>
+#include <linux/minmax.h>
+#include <linux/mm.h>
+#include <linux/types.h>
-/*
- * was unsigned short, but we might as well be ready for > 64kB I/O pages
+struct page;
+
+/**
+ * struct bio_vec - a contiguous range of physical memory addresses
+ * @bv_page: First page associated with the address range.
+ * @bv_len: Number of bytes in the address range.
+ * @bv_offset: Start of the address range relative to the start of @bv_page.
+ *
+ * The following holds for a bvec if n * PAGE_SIZE < bv_offset + bv_len:
+ *
+ * nth_page(@bv_page, n) == @bv_page + n
+ *
+ * This holds because page_is_mergeable() checks the above property.
*/
struct bio_vec {
struct page *bv_page;
@@ -40,10 +41,14 @@
unsigned int bi_idx; /* current index into bvl_vec */
- unsigned int bi_done; /* number of bytes completed */
-
unsigned int bi_bvec_done; /* number of bytes completed in
current bvec */
+};
+
+struct bvec_iter_all {
+ struct bio_vec bv;
+ int idx;
+ unsigned done;
};
/*
@@ -52,15 +57,38 @@
*/
#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
-#define bvec_iter_page(bvec, iter) \
+/* multi-page (mp_bvec) helpers */
+#define mp_bvec_iter_page(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_page)
-#define bvec_iter_len(bvec, iter) \
+#define mp_bvec_iter_len(bvec, iter) \
min((iter).bi_size, \
__bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
-#define bvec_iter_offset(bvec, iter) \
+#define mp_bvec_iter_offset(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
+
+#define mp_bvec_iter_page_idx(bvec, iter) \
+ (mp_bvec_iter_offset((bvec), (iter)) / PAGE_SIZE)
+
+#define mp_bvec_iter_bvec(bvec, iter) \
+((struct bio_vec) { \
+ .bv_page = mp_bvec_iter_page((bvec), (iter)), \
+ .bv_len = mp_bvec_iter_len((bvec), (iter)), \
+ .bv_offset = mp_bvec_iter_offset((bvec), (iter)), \
+})
+
+/* For building single-page bvec in flight */
+ #define bvec_iter_offset(bvec, iter) \
+ (mp_bvec_iter_offset((bvec), (iter)) % PAGE_SIZE)
+
+#define bvec_iter_len(bvec, iter) \
+ min_t(unsigned, mp_bvec_iter_len((bvec), (iter)), \
+ PAGE_SIZE - bvec_iter_offset((bvec), (iter)))
+
+#define bvec_iter_page(bvec, iter) \
+ (mp_bvec_iter_page((bvec), (iter)) + \
+ mp_bvec_iter_page_idx((bvec), (iter)))
#define bvec_iter_bvec(bvec, iter) \
((struct bio_vec) { \
@@ -72,50 +100,24 @@
static inline bool bvec_iter_advance(const struct bio_vec *bv,
struct bvec_iter *iter, unsigned bytes)
{
+ unsigned int idx = iter->bi_idx;
+
if (WARN_ONCE(bytes > iter->bi_size,
"Attempted to advance past end of bvec iter\n")) {
iter->bi_size = 0;
return false;
}
- while (bytes) {
- unsigned iter_len = bvec_iter_len(bv, *iter);
- unsigned len = min(bytes, iter_len);
+ iter->bi_size -= bytes;
+ bytes += iter->bi_bvec_done;
- bytes -= len;
- iter->bi_size -= len;
- iter->bi_bvec_done += len;
- iter->bi_done += len;
-
- if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
- iter->bi_bvec_done = 0;
- iter->bi_idx++;
- }
+ while (bytes && bytes >= bv[idx].bv_len) {
+ bytes -= bv[idx].bv_len;
+ idx++;
}
- return true;
-}
-static inline bool bvec_iter_rewind(const struct bio_vec *bv,
- struct bvec_iter *iter,
- unsigned int bytes)
-{
- while (bytes) {
- unsigned len = min(bytes, iter->bi_bvec_done);
-
- if (iter->bi_bvec_done == 0) {
- if (WARN_ONCE(iter->bi_idx == 0,
- "Attempted to rewind iter beyond "
- "bvec's boundaries\n")) {
- return false;
- }
- iter->bi_idx--;
- iter->bi_bvec_done = __bvec_iter_bvec(bv, *iter)->bv_len;
- continue;
- }
- bytes -= len;
- iter->bi_size += len;
- iter->bi_bvec_done -= len;
- }
+ iter->bi_idx = idx;
+ iter->bi_bvec_done = bytes;
return true;
}
@@ -141,4 +143,34 @@
.bi_bvec_done = 0, \
}
+static inline struct bio_vec *bvec_init_iter_all(struct bvec_iter_all *iter_all)
+{
+ iter_all->done = 0;
+ iter_all->idx = 0;
+
+ return &iter_all->bv;
+}
+
+static inline void bvec_advance(const struct bio_vec *bvec,
+ struct bvec_iter_all *iter_all)
+{
+ struct bio_vec *bv = &iter_all->bv;
+
+ if (iter_all->done) {
+ bv->bv_page++;
+ bv->bv_offset = 0;
+ } else {
+ bv->bv_page = bvec->bv_page + (bvec->bv_offset >> PAGE_SHIFT);
+ bv->bv_offset = bvec->bv_offset & ~PAGE_MASK;
+ }
+ bv->bv_len = min_t(unsigned int, PAGE_SIZE - bv->bv_offset,
+ bvec->bv_len - iter_all->done);
+ iter_all->done += bv->bv_len;
+
+ if (iter_all->done == bvec->bv_len) {
+ iter_all->idx++;
+ iter_all->done = 0;
+ }
+}
+
#endif /* __LINUX_BVEC_ITER_H */
--
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