diff --git a/drivers/block/zram/backend_zstd.c b/drivers/block/zram/backend_zstd.c
index d392d364ad2c..4be149370e0b 100644
--- a/drivers/block/zram/backend_zstd.c
+++ b/drivers/block/zram/backend_zstd.c
@@ -12,23 +12,52 @@ struct zstd_ctx {
 	zstd_dctx *dctx;
 	void *cctx_mem;
 	void *dctx_mem;
+	zstd_custom_mem ctx_mem;
+	zstd_cdict *cdict;
+	zstd_ddict *ddict;
 	s32 level;
 };
 
+/*
+ * Cctx allocator.customAlloc() can be called from zcomp_compress() under
+ * local-lock (per-CPU compression stream), in which case we must use
+ * GFP_ATOMIC.
+ */
+static void *zstd_ctx_alloc(void *opaque, size_t size)
+{
+	if (!preemptible())
+		return kvzalloc(size, GFP_ATOMIC);
+
+	return kvzalloc(size, GFP_KERNEL);
+}
+
+static void zstd_ctx_free(void *opaque, void *address)
+{
+	kvfree(address);
+}
+
 static void zstd_destroy(void *ctx)
 {
 	struct zstd_ctx *zctx = ctx;
 
-	vfree(zctx->cctx_mem);
-	vfree(zctx->dctx_mem);
+	if (zctx->cctx_mem)
+		vfree(zctx->cctx_mem);
+	else
+		zstd_free_cctx(zctx->cctx);
+
+	if (zctx->dctx_mem)
+		vfree(zctx->dctx_mem);
+	else
+		zstd_free_dctx(zctx->dctx);
+
+	zstd_free_cdict(zctx->cdict);
+	zstd_free_ddict(zctx->ddict);
 	kfree(zctx);
 }
 
 static void *zstd_create(struct zcomp_config *config)
 {
-	zstd_parameters params;
 	struct zstd_ctx *ctx;
-	size_t sz;
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
@@ -39,24 +68,62 @@ static void *zstd_create(struct zcomp_config *config)
 	else
 		ctx->level = zstd_default_clevel();
 
-	params = zstd_get_params(ctx->level, PAGE_SIZE);
-	sz = zstd_cctx_workspace_bound(&params.cParams);
-	ctx->cctx_mem = vzalloc(sz);
-	if (!ctx->cctx_mem)
-		goto error;
-
-	ctx->cctx = zstd_init_cctx(ctx->cctx_mem, sz);
-	if (!ctx->cctx)
-		goto error;
-
-	sz = zstd_dctx_workspace_bound();
-	ctx->dctx_mem = vzalloc(sz);
-	if (!ctx->dctx_mem)
-		goto error;
-
-	ctx->dctx = zstd_init_dctx(ctx->dctx_mem, sz);
-	if (!ctx->dctx)
-		goto error;
+	ctx->ctx_mem.customAlloc = zstd_ctx_alloc;
+	ctx->ctx_mem.customFree = zstd_ctx_free;
+
+	if (config->dict_sz == 0) {
+		zstd_parameters params;
+		size_t sz;
+
+		params = zstd_get_params(ctx->level, PAGE_SIZE);
+		sz = zstd_cctx_workspace_bound(&params.cParams);
+		ctx->cctx_mem = vzalloc(sz);
+		if (!ctx->cctx_mem)
+			goto error;
+
+		ctx->cctx = zstd_init_cctx(ctx->cctx_mem, sz);
+		if (!ctx->cctx)
+			goto error;
+
+		sz = zstd_dctx_workspace_bound();
+		ctx->dctx_mem = vzalloc(sz);
+		if (!ctx->dctx_mem)
+			goto error;
+
+		ctx->dctx = zstd_init_dctx(ctx->dctx_mem, sz);
+		if (!ctx->dctx)
+			goto error;
+	} else {
+		zstd_compression_parameters params;
+
+		ctx->cctx = zstd_create_cctx_advanced(ctx->ctx_mem);
+		if (!ctx->cctx)
+			goto error;
+
+		ctx->dctx = zstd_create_dctx_advanced(ctx->ctx_mem);
+		if (!ctx->dctx)
+			goto error;
+
+		params = zstd_get_cparams(ctx->level, PAGE_SIZE,
+					  config->dict_sz);
+
+		ctx->cdict = zstd_create_cdict_advanced(config->dict,
+							config->dict_sz,
+							ZSTD_dlm_byRef,
+							ZSTD_dct_auto,
+							params,
+							ctx->ctx_mem);
+		if (!ctx->cdict)
+			goto error;
+
+		ctx->ddict = zstd_create_ddict_advanced(config->dict,
+							config->dict_sz,
+							ZSTD_dlm_byRef,
+							ZSTD_dct_auto,
+							ctx->ctx_mem);
+		if (!ctx->ddict)
+			goto error;
+	}
 
 	return ctx;
 
@@ -72,8 +139,12 @@ static int zstd_compress(void *ctx, const unsigned char *src,
 	const zstd_parameters params = zstd_get_params(zctx->level, PAGE_SIZE);
 	size_t ret;
 
-	ret = zstd_compress_cctx(zctx->cctx, dst, *dst_len,
-				 src, PAGE_SIZE, &params);
+	if (!zctx->cdict)
+		ret = zstd_compress_cctx(zctx->cctx, dst, *dst_len,
+					 src, PAGE_SIZE, &params);
+	else
+		ret = zstd_compress_using_cdict(zctx->cctx, dst, *dst_len,
+						src, PAGE_SIZE, zctx->cdict);
 	if (zstd_is_error(ret))
 		return -EINVAL;
 	*dst_len = ret;
@@ -86,7 +157,12 @@ static int zstd_decompress(void *ctx, const unsigned char *src, size_t src_len,
 	struct zstd_ctx *zctx = ctx;
 	size_t ret;
 
-	ret = zstd_decompress_dctx(zctx->dctx, dst, PAGE_SIZE, src, src_len);
+	if (!zctx->ddict)
+		ret = zstd_decompress_dctx(zctx->dctx, dst, PAGE_SIZE,
+					   src, src_len);
+	else
+		ret = zstd_decompress_using_ddict(zctx->dctx, dst, PAGE_SIZE,
+						  src, src_len, zctx->ddict);
 	if (zstd_is_error(ret))
 		return -EINVAL;
 	return 0;
