From nobody Wed Dec 17 17:29:25 2025 Received: from out-187.mta0.migadu.com (out-187.mta0.migadu.com [91.218.175.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D0EC1E47CE for ; Tue, 7 Jan 2025 10:31:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736245869; cv=none; b=LIOvT78P9cnMdkphNeEEIrWhKBRCPmduigxwmQOwnAE2+pKWgRTKB2jB4hdGZcjb72MTcxh7LjacvuDGnW+PuIkr5xd3tyBXeaBi9uwpzK8FSl/wkCUxv1DPNixZiqqVsQt54vKVZdUn1myovHd91pxLuPuvtChm3UODZb61rsk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736245869; c=relaxed/simple; bh=BmsOyAK6sFY5bd1TMgzNx+wJVAuRK2Y62I+8s21jW74=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=L6MU2ZE2TOCfFlVLhXDDRYI69s9ui9xjy8x6+1CT398MulA10DOcEyhgyDyM1/2uoVk6ljWoIZIXH8jaZCRyK4JB9yzteEcnf0p3PC+48BfTiSd6dCsQx3vp0jMPidNGykMNaNmwKBEbFwsPGmIw9NAA0bPQJd5ALwqdVFsx5mw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=W/dQrVVe; arc=none smtp.client-ip=91.218.175.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="W/dQrVVe" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1736245863; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fUKtV0V4M4Ct0Xe87xvFiPtfAJ7Jk8lSopNav9KsJCE=; b=W/dQrVVeaa5UgNbBhAIGAPW0JuO5SBDHro6LAk3e+EaZOMRrfL3JQ/I4lHpfi7xy/iYCIl KdWR2Q/4pbCXY5Fkanbh4vhaf1bN8T2pUFO43tDNevD2iCZ3X8BCv+Pyy64KwB+oghCs7A K8DlA1+ZtTqBn1iDPq49KrQH5+8cmNo= From: Dongsheng Yang To: axboe@kernel.dk, dan.j.williams@intel.com, gregory.price@memverge.com, John@groves.net, Jonathan.Cameron@Huawei.com, bbhushan2@marvell.com, chaitanyak@nvidia.com, rdunlap@infradead.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, linux-bcache@vger.kernel.org, Dongsheng Yang Subject: [PATCH v3 3/8] cbd: introduce cbd_segment Date: Tue, 7 Jan 2025 10:30:19 +0000 Message-Id: <20250107103024.326986-4-dongsheng.yang@linux.dev> In-Reply-To: <20250107103024.326986-1-dongsheng.yang@linux.dev> References: <20250107103024.326986-1-dongsheng.yang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" The `cbd_segments` is an abstraction of the data area in transport. The data area in transport is divided into segments. The specific use of this area is determined by `cbd_seg_type`. For example, `cbd_blkdev` and `cbd_backend` data transfers need to access a segment of the type `cbds_type_channel`. Signed-off-by: Dongsheng Yang --- drivers/block/cbd/cbd_segment.c | 311 ++++++++++++++++++++++++++++++++ drivers/block/cbd/cbd_segment.h | 104 +++++++++++ 2 files changed, 415 insertions(+) create mode 100644 drivers/block/cbd/cbd_segment.c create mode 100644 drivers/block/cbd/cbd_segment.h diff --git a/drivers/block/cbd/cbd_segment.c b/drivers/block/cbd/cbd_segmen= t.c new file mode 100644 index 000000000000..fc1c4701d343 --- /dev/null +++ b/drivers/block/cbd/cbd_segment.c @@ -0,0 +1,311 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include + +#include "cbd_internal.h" +#include "cbd_transport.h" +#include "cbd_segment.h" + +static ssize_t type_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct cbd_segment_device *segment_dev; + struct cbd_segment_info *segment_info; + + segment_dev =3D container_of(dev, struct cbd_segment_device, dev); + segment_info =3D cbdt_segment_info_read(segment_dev->cbdt, segment_dev->i= d); + if (!segment_info) + return 0; + + if (segment_info->state =3D=3D CBD_SEGMENT_STATE_NONE) + return 0; + + return sprintf(buf, "%s\n", cbds_type_str(segment_info->type)); +} + +static DEVICE_ATTR_ADMIN_RO(type); + +static struct attribute *cbd_segment_attrs[] =3D { + &dev_attr_type.attr, + NULL +}; + +static struct attribute_group cbd_segment_attr_group =3D { + .attrs =3D cbd_segment_attrs, +}; + +static const struct attribute_group *cbd_segment_attr_groups[] =3D { + &cbd_segment_attr_group, + NULL +}; + +static void cbd_segment_release(struct device *dev) +{ +} + +const struct device_type cbd_segment_type =3D { + .name =3D "cbd_segment", + .groups =3D cbd_segment_attr_groups, + .release =3D cbd_segment_release, +}; + +const struct device_type cbd_segments_type =3D { + .name =3D "cbd_segments", + .release =3D cbd_segment_release, +}; + +void cbd_segment_init(struct cbd_transport *cbdt, struct cbd_segment *segm= ent, + struct cbds_init_options *options) +{ + segment->cbdt =3D cbdt; + segment->seg_id =3D options->seg_id; + segment->seg_ops =3D options->seg_ops; + segment->data_size =3D CBDT_SEG_SIZE - options->data_off; + + segment->data =3D cbd_segment_addr(segment) + options->data_off; +} + +void cbd_segment_clear(struct cbd_transport *cbdt, u32 seg_id) +{ + struct cbd_segment_info *segment_info; + + segment_info =3D cbdt_get_segment_info(cbdt, seg_id); + cbdt_zero_range(cbdt, segment_info, CBDT_SEG_SIZE); +} + +void cbd_segment_info_clear(struct cbd_segment *segment) +{ + cbdt_segment_info_clear(segment->cbdt, segment->seg_id); +} + +void cbds_copy_data(struct cbd_seg_pos *dst_pos, + struct cbd_seg_pos *src_pos, u32 len) +{ + u32 copied =3D 0; + u32 to_copy; + + while (copied < len) { + if (dst_pos->off >=3D dst_pos->segment->data_size) + dst_pos->segment->seg_ops->sanitize_pos(dst_pos); + if (src_pos->off >=3D src_pos->segment->data_size) + src_pos->segment->seg_ops->sanitize_pos(src_pos); + + to_copy =3D len - copied; + + if (to_copy > dst_pos->segment->data_size - dst_pos->off) + to_copy =3D dst_pos->segment->data_size - dst_pos->off; + if (to_copy > src_pos->segment->data_size - src_pos->off) + to_copy =3D src_pos->segment->data_size - src_pos->off; + + memcpy_flushcache(dst_pos->segment->data + dst_pos->off, src_pos->segmen= t->data + src_pos->off, to_copy); + + copied +=3D to_copy; + cbds_pos_advance(dst_pos, to_copy); + cbds_pos_advance(src_pos, to_copy); + } +} + +int cbds_copy_to_bio(struct cbd_segment *segment, + u32 data_off, u32 data_len, struct bio *bio, u32 bio_off) +{ + struct bio_vec bv; + struct bvec_iter iter; + void *dst; + u32 to_copy, page_off =3D 0; + struct cbd_seg_pos pos =3D { .segment =3D segment, + .off =3D data_off }; +next: + bio_for_each_segment(bv, bio, iter) { + if (bio_off > bv.bv_len) { + bio_off -=3D bv.bv_len; + continue; + } + page_off =3D bv.bv_offset; + page_off +=3D bio_off; + bio_off =3D 0; + + dst =3D kmap_local_page(bv.bv_page); +again: + if (pos.off >=3D pos.segment->data_size) + segment->seg_ops->sanitize_pos(&pos); + segment =3D pos.segment; + + to_copy =3D min(bv.bv_offset + bv.bv_len - page_off, + segment->data_size - pos.off); + if (to_copy > data_len) + to_copy =3D data_len; + + flush_dcache_page(bv.bv_page); + memcpy(dst + page_off, segment->data + pos.off, to_copy); + + /* advance */ + pos.off +=3D to_copy; + page_off +=3D to_copy; + data_len -=3D to_copy; + if (!data_len) { + kunmap_local(dst); + return 0; + } + + /* more data in this bv page */ + if (page_off < bv.bv_offset + bv.bv_len) + goto again; + kunmap_local(dst); + } + + if (bio->bi_next) { + bio =3D bio->bi_next; + goto next; + } + + return 0; +} + +void cbds_copy_from_bio(struct cbd_segment *segment, + u32 data_off, u32 data_len, struct bio *bio, u32 bio_off) +{ + struct bio_vec bv; + struct bvec_iter iter; + void *src; + u32 to_copy, page_off =3D 0; + struct cbd_seg_pos pos =3D { .segment =3D segment, + .off =3D data_off }; +next: + bio_for_each_segment(bv, bio, iter) { + if (bio_off > bv.bv_len) { + bio_off -=3D bv.bv_len; + continue; + } + page_off =3D bv.bv_offset; + page_off +=3D bio_off; + bio_off =3D 0; + + src =3D kmap_local_page(bv.bv_page); +again: + if (pos.off >=3D pos.segment->data_size) + segment->seg_ops->sanitize_pos(&pos); + segment =3D pos.segment; + + to_copy =3D min(bv.bv_offset + bv.bv_len - page_off, + segment->data_size - pos.off); + if (to_copy > data_len) + to_copy =3D data_len; + + memcpy_flushcache(segment->data + pos.off, src + page_off, to_copy); + flush_dcache_page(bv.bv_page); + + /* advance */ + pos.off +=3D to_copy; + page_off +=3D to_copy; + data_len -=3D to_copy; + if (!data_len) { + kunmap_local(src); + return; + } + + /* more data in this bv page */ + if (page_off < bv.bv_offset + bv.bv_len) + goto again; + kunmap_local(src); + } + + if (bio->bi_next) { + bio =3D bio->bi_next; + goto next; + } +} + +u32 cbd_seg_crc(struct cbd_segment *segment, u32 data_off, u32 data_len) +{ + u32 crc =3D 0; + u32 crc_size; + struct cbd_seg_pos pos =3D { .segment =3D segment, + .off =3D data_off }; + + while (data_len) { + if (pos.off >=3D pos.segment->data_size) + segment->seg_ops->sanitize_pos(&pos); + segment =3D pos.segment; + + crc_size =3D min(segment->data_size - pos.off, data_len); + + crc =3D crc32(crc, segment->data + pos.off, crc_size); + + data_len -=3D crc_size; + pos.off +=3D crc_size; + } + + return crc; +} + +int cbds_map_pages(struct cbd_segment *segment, + struct bio *bio, + u32 off, u32 size) +{ + struct cbd_transport *cbdt =3D segment->cbdt; + u32 done =3D 0; + struct page *page; + u32 page_off; + int ret =3D 0; + int id; + + id =3D dax_read_lock(); + while (size) { + unsigned int len =3D min_t(size_t, PAGE_SIZE, size); + struct cbd_seg_pos pos =3D { .segment =3D segment, + .off =3D off + done }; + + if (pos.off >=3D pos.segment->data_size) + segment->seg_ops->sanitize_pos(&pos); + segment =3D pos.segment; + + u64 transport_off =3D segment->data - + (void *)cbdt->transport_info_addr + pos.off; + + page =3D cbdt_page(cbdt, transport_off, &page_off); + + ret =3D bio_add_page(bio, page, len, 0); + if (unlikely(ret !=3D len)) { + cbd_segment_err(segment, "failed to add page\n"); + goto out; + } + + done +=3D len; + size -=3D len; + } + + ret =3D 0; +out: + dax_read_unlock(id); + return ret; +} + +int cbds_pos_advance(struct cbd_seg_pos *seg_pos, u32 len) +{ + u32 to_advance; + + while (len) { + to_advance =3D len; + + if (seg_pos->off >=3D seg_pos->segment->data_size) + seg_pos->segment->seg_ops->sanitize_pos(seg_pos); + + if (to_advance > seg_pos->segment->data_size - seg_pos->off) + to_advance =3D seg_pos->segment->data_size - seg_pos->off; + + seg_pos->off +=3D to_advance; + + len -=3D to_advance; + } + + return 0; +} + +void *cbd_segment_addr(struct cbd_segment *segment) +{ + struct cbd_segment_info *seg_info; + + seg_info =3D cbdt_get_segment_info(segment->cbdt, segment->seg_id); + + return (void *)seg_info; +} diff --git a/drivers/block/cbd/cbd_segment.h b/drivers/block/cbd/cbd_segmen= t.h new file mode 100644 index 000000000000..99fccb8c49ba --- /dev/null +++ b/drivers/block/cbd/cbd_segment.h @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _CBD_SEGMENT_H +#define _CBD_SEGMENT_H + +#include + +#include "cbd_internal.h" + +#define cbd_segment_err(segment, fmt, ...) \ + cbdt_err(segment->cbdt, "segment%d: " fmt, \ + segment->seg_id, ##__VA_ARGS__) +#define cbd_segment_info(segment, fmt, ...) \ + cbdt_info(segment->cbdt, "segment%d: " fmt, \ + segment->seg_id, ##__VA_ARGS__) +#define cbd_segment_debug(segment, fmt, ...) \ + cbdt_debug(segment->cbdt, "segment%d: " fmt, \ + segment->seg_id, ##__VA_ARGS__) + + +CBD_DEVICE(segment); + +#define CBD_SEGMENT_STATE_NONE 0 +#define CBD_SEGMENT_STATE_RUNNING 1 + +#define CBDS_TYPE_NONE 0 +#define CBDS_TYPE_CHANNEL 1 +#define CBDS_TYPE_CACHE 2 + +static inline const char *cbds_type_str(u8 type) +{ + if (type =3D=3D CBDS_TYPE_CHANNEL) + return "channel"; + else if (type =3D=3D CBDS_TYPE_CACHE) + return "cache"; + + return "Unknown"; +} + +struct cbd_segment_info { + struct cbd_meta_header meta_header; /* Metadata header for the segment */ + u8 type; + u8 state; + u16 flags; + u32 next_seg; + u32 backend_id; +}; + +#define CBD_SEG_INFO_FLAGS_HAS_NEXT (1 << 0) + +static inline bool cbd_segment_info_has_next(struct cbd_segment_info *seg_= info) +{ + return (seg_info->flags & CBD_SEG_INFO_FLAGS_HAS_NEXT); +} + +struct cbd_seg_pos { + struct cbd_segment *segment; /* Segment associated with the position */ + u32 off; /* Offset within the segment */ +}; + +struct cbd_seg_ops { + void (*sanitize_pos)(struct cbd_seg_pos *pos); +}; + +struct cbds_init_options { + u8 type; + u8 state; + u32 seg_id; + u32 data_off; + struct cbd_seg_ops *seg_ops; +}; + +struct cbd_segment { + struct cbd_transport *cbdt; + struct cbd_seg_ops *seg_ops; + u32 seg_id; + + void *data; + u32 data_size; +}; + +void cbd_segment_info_clear(struct cbd_segment *segment); +void cbd_segment_clear(struct cbd_transport *cbdt, u32 segment_id); +void cbd_segment_init(struct cbd_transport *cbdt, struct cbd_segment *segm= ent, + struct cbds_init_options *options); +int cbds_copy_to_bio(struct cbd_segment *segment, + u32 data_off, u32 data_len, struct bio *bio, u32 bio_off); +void cbds_copy_from_bio(struct cbd_segment *segment, + u32 data_off, u32 data_len, struct bio *bio, u32 bio_off); +u32 cbd_seg_crc(struct cbd_segment *segment, u32 data_off, u32 data_len); +int cbds_map_pages(struct cbd_segment *segment, + struct bio *bio, + u32 off, u32 size); +int cbds_pos_advance(struct cbd_seg_pos *seg_pos, u32 len); +void cbds_copy_data(struct cbd_seg_pos *dst_pos, + struct cbd_seg_pos *src_pos, u32 len); +void *cbd_segment_addr(struct cbd_segment *segment); + +#define cbd_for_each_segment_info(cbdt, i, segment_info) \ + for (i =3D 0; \ + i < cbdt->transport_info.segment_num && \ + (segment_info =3D cbdt_segment_info_read(cbdt, i)); \ + i++) + +#endif /* _CBD_SEGMENT_H */ --=20 2.34.1