ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

1 files changed, 315 insertions, 0 deletions

diff --git a/crypto/zstd.c b/crypto/zstd.c
new file mode 100644
index 000000000..556f5d2bd
--- /dev/null
+++ b/crypto/zstd.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Cryptographic API.
+ *
+ * Copyright (c) 2017-present, Facebook, Inc.
+ */
+#include <linux/crypto.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/overflow.h>
+#include <linux/vmalloc.h>
+#include <linux/zstd.h>
+#include <crypto/internal/acompress.h>
+#include <crypto/scatterwalk.h>
+
+
+#define ZSTD_DEF_LEVEL		3
+#define ZSTD_MAX_WINDOWLOG	18
+#define ZSTD_MAX_SIZE		BIT(ZSTD_MAX_WINDOWLOG)
+
+struct zstd_ctx {
+	zstd_cctx *cctx;
+	zstd_dctx *dctx;
+	size_t wksp_size;
+	zstd_parameters params;
+	u8 wksp[] __aligned(8) __counted_by(wksp_size);
+};
+
+static DEFINE_MUTEX(zstd_stream_lock);
+
+static void *zstd_alloc_stream(void)
+{
+	zstd_parameters params;
+	struct zstd_ctx *ctx;
+	size_t wksp_size;
+
+	params = zstd_get_params(ZSTD_DEF_LEVEL, ZSTD_MAX_SIZE);
+
+	wksp_size = max(zstd_cstream_workspace_bound(&params.cParams),
+			zstd_dstream_workspace_bound(ZSTD_MAX_SIZE));
+	if (!wksp_size)
+		return ERR_PTR(-EINVAL);
+
+	ctx = kvmalloc_flex(*ctx, wksp, wksp_size);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+
+	ctx->params = params;
+	ctx->wksp_size = wksp_size;
+
+	return ctx;
+}
+
+static void zstd_free_stream(void *ctx)
+{
+	kvfree(ctx);
+}
+
+static struct crypto_acomp_streams zstd_streams = {
+	.alloc_ctx = zstd_alloc_stream,
+	.free_ctx = zstd_free_stream,
+};
+
+static int zstd_init(struct crypto_acomp *acomp_tfm)
+{
+	int ret = 0;
+
+	mutex_lock(&zstd_stream_lock);
+	ret = crypto_acomp_alloc_streams(&zstd_streams);
+	mutex_unlock(&zstd_stream_lock);
+
+	return ret;
+}
+
+static int zstd_compress_one(struct acomp_req *req, struct zstd_ctx *ctx,
+			     const void *src, void *dst, unsigned int *dlen)
+{
+	size_t out_len;
+
+	ctx->cctx = zstd_init_cctx(ctx->wksp, ctx->wksp_size);
+	if (!ctx->cctx)
+		return -EINVAL;
+
+	out_len = zstd_compress_cctx(ctx->cctx, dst, req->dlen, src, req->slen,
+				     &ctx->params);
+	if (zstd_is_error(out_len))
+		return -EINVAL;
+
+	*dlen = out_len;
+
+	return 0;
+}
+
+static int zstd_compress(struct acomp_req *req)
+{
+	struct crypto_acomp_stream *s;
+	unsigned int pos, scur, dcur;
+	unsigned int total_out = 0;
+	bool data_available = true;
+	zstd_out_buffer outbuf;
+	struct acomp_walk walk;
+	zstd_in_buffer inbuf;
+	struct zstd_ctx *ctx;
+	size_t pending_bytes;
+	size_t num_bytes;
+	int ret;
+
+	s = crypto_acomp_lock_stream_bh(&zstd_streams);
+	ctx = s->ctx;
+
+	ret = acomp_walk_virt(&walk, req, true);
+	if (ret)
+		goto out;
+
+	ctx->cctx = zstd_init_cstream(&ctx->params, 0, ctx->wksp, ctx->wksp_size);
+	if (!ctx->cctx) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	do {
+		dcur = acomp_walk_next_dst(&walk);
+		if (!dcur) {
+			ret = -ENOSPC;
+			goto out;
+		}
+
+		outbuf.pos = 0;
+		outbuf.dst = (u8 *)walk.dst.virt.addr;
+		outbuf.size = dcur;
+
+		do {
+			scur = acomp_walk_next_src(&walk);
+			if (dcur == req->dlen && scur == req->slen) {
+				ret = zstd_compress_one(req, ctx, walk.src.virt.addr,
+							walk.dst.virt.addr, &total_out);
+				acomp_walk_done_src(&walk, scur);
+				acomp_walk_done_dst(&walk, dcur);
+				goto out;
+			}
+
+			if (scur) {
+				inbuf.pos = 0;
+				inbuf.src = walk.src.virt.addr;
+				inbuf.size = scur;
+			} else {
+				data_available = false;
+				break;
+			}
+
+			num_bytes = zstd_compress_stream(ctx->cctx, &outbuf, &inbuf);
+			if (ZSTD_isError(num_bytes)) {
+				ret = -EIO;
+				goto out;
+			}
+
+			pending_bytes = zstd_flush_stream(ctx->cctx, &outbuf);
+			if (ZSTD_isError(pending_bytes)) {
+				ret = -EIO;
+				goto out;
+			}
+			acomp_walk_done_src(&walk, inbuf.pos);
+		} while (dcur != outbuf.pos);
+
+		total_out += outbuf.pos;
+		acomp_walk_done_dst(&walk, dcur);
+	} while (data_available);
+
+	pos = outbuf.pos;
+	num_bytes = zstd_end_stream(ctx->cctx, &outbuf);
+	if (ZSTD_isError(num_bytes))
+		ret = -EIO;
+	else
+		total_out += (outbuf.pos - pos);
+
+out:
+	if (ret)
+		req->dlen = 0;
+	else
+		req->dlen = total_out;
+
+	crypto_acomp_unlock_stream_bh(s);
+
+	return ret;
+}
+
+static int zstd_decompress_one(struct acomp_req *req, struct zstd_ctx *ctx,
+			       const void *src, void *dst, unsigned int *dlen)
+{
+	size_t out_len;
+
+	ctx->dctx = zstd_init_dctx(ctx->wksp, ctx->wksp_size);
+	if (!ctx->dctx)
+		return -EINVAL;
+
+	out_len = zstd_decompress_dctx(ctx->dctx, dst, req->dlen, src, req->slen);
+	if (zstd_is_error(out_len))
+		return -EINVAL;
+
+	*dlen = out_len;
+
+	return 0;
+}
+
+static int zstd_decompress(struct acomp_req *req)
+{
+	struct crypto_acomp_stream *s;
+	unsigned int total_out = 0;
+	unsigned int scur, dcur;
+	zstd_out_buffer outbuf;
+	struct acomp_walk walk;
+	zstd_in_buffer inbuf;
+	struct zstd_ctx *ctx;
+	size_t pending_bytes;
+	int ret;
+
+	s = crypto_acomp_lock_stream_bh(&zstd_streams);
+	ctx = s->ctx;
+
+	ret = acomp_walk_virt(&walk, req, true);
+	if (ret)
+		goto out;
+
+	ctx->dctx = zstd_init_dstream(ZSTD_MAX_SIZE, ctx->wksp, ctx->wksp_size);
+	if (!ctx->dctx) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	do {
+		scur = acomp_walk_next_src(&walk);
+		if (scur) {
+			inbuf.pos = 0;
+			inbuf.size = scur;
+			inbuf.src = walk.src.virt.addr;
+		} else {
+			break;
+		}
+
+		do {
+			dcur = acomp_walk_next_dst(&walk);
+			if (dcur == req->dlen && scur == req->slen) {
+				ret = zstd_decompress_one(req, ctx, walk.src.virt.addr,
+							  walk.dst.virt.addr, &total_out);
+				acomp_walk_done_dst(&walk, dcur);
+				acomp_walk_done_src(&walk, scur);
+				goto out;
+			}
+
+			if (!dcur) {
+				ret = -ENOSPC;
+				goto out;
+			}
+
+			outbuf.pos = 0;
+			outbuf.dst = (u8 *)walk.dst.virt.addr;
+			outbuf.size = dcur;
+
+			pending_bytes = zstd_decompress_stream(ctx->dctx, &outbuf, &inbuf);
+			if (ZSTD_isError(pending_bytes)) {
+				ret = -EIO;
+				goto out;
+			}
+
+			total_out += outbuf.pos;
+
+			acomp_walk_done_dst(&walk, outbuf.pos);
+		} while (inbuf.pos != scur);
+
+		acomp_walk_done_src(&walk, scur);
+	} while (ret == 0);
+
+out:
+	if (ret)
+		req->dlen = 0;
+	else
+		req->dlen = total_out;
+
+	crypto_acomp_unlock_stream_bh(s);
+
+	return ret;
+}
+
+static struct acomp_alg zstd_acomp = {
+	.base = {
+		.cra_name = "zstd",
+		.cra_driver_name = "zstd-generic",
+		.cra_flags = CRYPTO_ALG_REQ_VIRT,
+		.cra_module = THIS_MODULE,
+	},
+	.init = zstd_init,
+	.compress = zstd_compress,
+	.decompress = zstd_decompress,
+};
+
+static int __init zstd_mod_init(void)
+{
+	return crypto_register_acomp(&zstd_acomp);
+}
+
+static void __exit zstd_mod_fini(void)
+{
+	crypto_unregister_acomp(&zstd_acomp);
+	crypto_acomp_free_streams(&zstd_streams);
+}
+
+module_init(zstd_mod_init);
+module_exit(zstd_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Zstd Compression Algorithm");
+MODULE_ALIAS_CRYPTO("zstd");