acomp-dpusm: add initial implementation

Add initial implementation of acomp-dpusm plug-in.

Signed-off-by: Giovanni Cabiddu <[email protected]>

Author: gcabiddu

Makefile

@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (C) 2025 Intel Corporation
+# These contents may have been developed with support from one or more
+# Intel-operated generative artificial intelligence solutions.
+
+# Define the kernel source directory
+KERNELDIR ?= /lib/modules/$(shell uname -r)/build
+
+# Define the module name
+MODULE_NAME := acomp-dpusm
+
+# Define the home path for the DPUSM and ZFS source directories
+HOME_PATH ?= /devel/zfs
+
+# Define the include paths for DPUSM
+DPUSM_INCLUDE := $(HOME_PATH)/dpusm/include
+
+# Define the include paths for ZFS
+ZFS_INCLUDE := $(HOME_PATH)/zfs/include
+
+# Define the source files for the module
+SRC_FILES := provider.c compress.c
+
+# Define the object files for the module
+OBJ_FILES := $(SRC_FILES:.c=.o)
+
+# Define the location of the module symvers file for DPUSM
+KBUILD_EXTRA_SYMBOLS := $(HOME_PATH)/dpusm/Module.symvers
+
+ifneq ($(KERNELRELEASE),)
+ccflags-y := -I$(DPUSM_INCLUDE) -I$(ZFS_INCLUDE)
+obj-m := $(MODULE_NAME).o
+$(MODULE_NAME)-y := $(OBJ_FILES)
+else
+PWD := $(shell pwd)
+
+default:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) C=2 W=1 modules
+
+clean:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
+endif
+
+.PHONY: clean

compress.c

@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Intel Corporation
+ * These contents may have been developed with support from one or more
+ * Intel-operated generative artificial intelligence solutions.
+ */
+#include "compress.h"
+
+#include <crypto/acompress.h>
+#include <linux/completion.h>
+#include <linux/pagemap.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+static struct crypto_acomp *acomp_tfm;
+static bool acomp_init_done;
+
+int acomp_init(void)
+{
+	acomp_tfm = crypto_alloc_acomp("zlib-deflate", 0, 0);
+	if (IS_ERR(acomp_tfm)) {
+		pr_err("Failed to allocate zlib-deflate acomp transform\n");
+		return PTR_ERR(acomp_tfm);
+	}
+
+	acomp_init_done = true;
+
+	return 0;
+}
+
+void acomp_exit(void)
+{
+	if (!acomp_init_done)
+		return;
+
+	if (acomp_tfm) {
+		crypto_free_acomp(acomp_tfm);
+		acomp_tfm = NULL;
+	}
+	acomp_init_done = false;
+}
+
+enum comp_dir {
+	DECOMPRESS = 0,
+	COMPRESS = 1,
+};
+
+static int acomp_comp_decomp_sg(enum comp_dir dir, struct scatterlist *src, int src_len,
+				struct scatterlist *dst, int dst_len, size_t *c_len)
+{
+	struct crypto_wait wait;
+	struct acomp_req *req;
+	int ret;
+
+	pr_debug("[%s] dir: %s, src_len: %d, dst_len: %d\n", __func__,
+		 dir == COMPRESS ? "COMPRESS" : "DECOMPRESS", src_len, dst_len);
+
+	req = acomp_request_alloc(acomp_tfm);
+	if (!req) {
+		pr_err("Failed to allocate acomp request\n");
+		return -ENOMEM;
+	}
+
+	crypto_init_wait(&wait);
+	acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+				   crypto_req_done, &wait);
+
+	acomp_request_set_params(req, src, dst, src_len, dst_len);
+
+	if (dir == COMPRESS)
+		ret = crypto_acomp_compress(req);
+	else
+		ret = crypto_acomp_decompress(req);
+
+	ret = crypto_wait_req(ret, &wait);
+	if (ret)
+		goto out;
+
+	*c_len = req->dlen;
+
+out:
+	acomp_request_free(req);
+	pr_debug("[%s] ret: %d, dlen=%zu\n", __func__, ret, *c_len);
+
+	return ret;
+}
+
+static int vmalloc_to_sg(const void *vmem, size_t size, struct scatterlist *sgl, int nents)
+{
+	unsigned long vaddr = (unsigned long)vmem;
+	unsigned long offset;
+	size_t remaining = size;
+	struct page *page;
+	int sg_count = 0;
+
+	sg_init_table(sgl, nents);
+
+	while (remaining > 0) {
+		page = vmalloc_to_page((void *)vaddr);
+		if (!page) {
+			pr_err("Failed to retrieve page for vaddr: 0x%lx\n", vaddr);
+			return -EINVAL;
+		}
+
+		offset = vaddr & (PAGE_SIZE - 1);
+		size_t len = min((size_t)(PAGE_SIZE - offset), remaining);
+
+		sg_set_page(&sgl[sg_count], page, len, offset);
+
+		vaddr += len;
+		remaining -= len;
+		sg_count++;
+
+		if (sg_count >= nents && remaining > 0) {
+			pr_err("Not enough scatterlist entries for memory size: %zu\n", size);
+			return -ENOMEM;
+		}
+	}
+
+	sg_mark_end(&sgl[sg_count - 1]);
+
+	return 0;
+}
+
+static int count_pages(const void *vmem, size_t size)
+{
+	unsigned long vaddr = (unsigned long)vmem;
+	size_t remaining = size;
+	int page_count = 0;
+
+	while (remaining > 0) {
+		size_t len = min((size_t)(PAGE_SIZE - (vaddr & (PAGE_SIZE - 1))), remaining);
+
+		vaddr += len;
+		remaining -= len;
+		page_count++;
+	}
+
+	return page_count;
+}
+
+static int alloc_scatterlist(const void *vmem, size_t size, struct scatterlist **sgl)
+{
+	struct scatterlist *sg = NULL;
+	int ret = 0;
+	int pages;
+
+	if (!is_vmalloc_addr(vmem)) {
+		sg = kmalloc(sizeof(*sg), GFP_KERNEL);
+		if (!sg) {
+			*sgl = NULL;
+			return -ENOMEM;
+		}
+
+		sg_init_one(sg, vmem, size);
+
+		*sgl = sg;
+		return 0;
+	}
+
+	pages = count_pages(vmem, size);
+	if (pages <= 0) {
+		pr_err("Failed to count pages for memory\n");
+		return -EINVAL;
+	}
+
+	sg = kmalloc_array(pages, sizeof(struct scatterlist), GFP_KERNEL);
+	if (!sg)
+		return -ENOMEM;
+
+	memset(sg, 0, sizeof(struct scatterlist) * pages);
+
+	ret = vmalloc_to_sg(vmem, size, sg, pages);
+	if (ret) {
+		pr_err("Failed to map vmalloc memory to scatterlist\n");
+		kfree(sg);
+		*sgl = NULL;
+		return ret;
+	}
+
+	*sgl = sg;
+	return ret;
+}
+
+static int acomp_comp_decomp(enum comp_dir dir, void *src, int src_len,
+			     void *dst, int dst_len, size_t *c_len)
+{
+	struct scatterlist *src_sg, *dst_sg;
+	int ret;
+
+	ret = alloc_scatterlist(src, src_len, &src_sg);
+	if (ret) {
+		pr_err("Failed to allocate scatterlist for SRC memory\n");
+		return ret;
+	}
+
+	ret = alloc_scatterlist(dst, dst_len, &dst_sg);
+	if (ret) {
+		pr_err("Failed to allocate scatterlist for DST memory\n");
+		kfree(src_sg);
+		return ret;
+	}
+
+	ret = acomp_comp_decomp_sg(dir, src_sg, src_len, dst_sg, dst_len, c_len);
+
+	kfree(src_sg);
+	kfree(dst_sg);
+
+	return ret;
+}
+
+int acomp_compress(void *src, int src_len, void *dst, int dst_len, size_t *c_len)
+{
+	return acomp_comp_decomp(COMPRESS, src, src_len, dst, dst_len, c_len);
+}
+
+int acomp_decompress(void *src, int src_len, void *dst, int dst_len, size_t *c_len)
+{
+	return acomp_comp_decomp(DECOMPRESS, src, src_len, dst, dst_len, c_len);
+}

compress.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Intel Corporation
+ * These contents may have been developed with support from one or more
+ * Intel-operated generative artificial intelligence solutions.
+ */
+#ifndef _ACOMP_COMPRESS_H
+#define _ACOMP_COMPRESS_H
+
+#include <linux/types.h>
+
+int acomp_init(void);
+void acomp_exit(void);
+int acomp_compress(void *src, int src_len, void *dst, int dst_len, size_t *c_len);
+int acomp_decompress(void *src, int src_len, void *dst, int dst_len, size_t *c_len);
+
+#endif /* _ACOMP_COMPRESS_H */