crypto: scomp - Drop the dst scratch buffer

As deflate has been converted over to acomp, and cavium zip has been
removed, there are no longer any scomp algorithms that can be used
by IPsec.

Since IPsec was the only user of the dst scratch buffer, remove it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: herbertx

crypto/scompress.c

@@ -25,15 +25,12 @@
 
 #include "compress.h"
 
-#define SCOMP_SCRATCH_SIZE 65400
-
 struct scomp_scratch {
 	spinlock_t	lock;
 	union {
 		void	*src;
 		unsigned long saddr;
 	};
-	void		*dst;
 };
 
 static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
@@ -78,29 +75,20 @@ static void crypto_scomp_free_scratches(void)
 		scratch = per_cpu_ptr(&scomp_scratch, i);
 
 		free_page(scratch->saddr);
-		kvfree(scratch->dst);
 		scratch->src = NULL;
-		scratch->dst = NULL;
 	}
 }
 
 static int scomp_alloc_scratch(struct scomp_scratch *scratch, int cpu)
 {
 	int node = cpu_to_node(cpu);
 	struct page *page;
-	void *mem;
 
-	mem = kvmalloc_node(SCOMP_SCRATCH_SIZE, GFP_KERNEL, node);
-	if (!mem)
-		return -ENOMEM;
 	page = alloc_pages_node(node, GFP_KERNEL, 0);
-	if (!page) {
-		kvfree(mem);
+	if (!page)
 		return -ENOMEM;
-	}
 	spin_lock_bh(&scratch->lock);
 	scratch->src = page_address(page);
-	scratch->dst = mem;
 	spin_unlock_bh(&scratch->lock);
 	return 0;
 }
@@ -181,6 +169,8 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 {
 	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 	struct crypto_scomp **tfm_ctx = acomp_tfm_ctx(tfm);
+	bool src_isvirt = acomp_request_src_isvirt(req);
+	bool dst_isvirt = acomp_request_dst_isvirt(req);
 	struct crypto_scomp *scomp = *tfm_ctx;
 	struct crypto_acomp_stream *stream;
 	struct scomp_scratch *scratch;
@@ -200,13 +190,33 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 	if (!req->dst || !dlen)
 		return -EINVAL;
 
-	stream = crypto_acomp_lock_stream_bh(&crypto_scomp_alg(scomp)->streams);
-	scratch = scomp_lock_scratch();
+	if (dst_isvirt)
+		dst = req->dvirt;
+	else {
+		if (acomp_request_dst_isfolio(req)) {
+			dpage = folio_page(req->dfolio, 0);
+			doff = req->doff;
+		} else if (dlen <= req->dst->length) {
+			dpage = sg_page(req->dst);
+			doff = req->dst->offset;
+		} else
+			return -ENOSYS;
+
+		dpage = nth_page(dpage, doff / PAGE_SIZE);
+		doff = offset_in_page(doff);
+
+		n = dlen / PAGE_SIZE;
+		n += (offset_in_page(dlen) + doff - 1) / PAGE_SIZE;
+		if (PageHighMem(dpage + n) &&
+		    size_add(doff, dlen) > PAGE_SIZE)
+			return -ENOSYS;
+		dst = kmap_local_page(dpage) + doff;
+	}
 
-	if (acomp_request_src_isvirt(req))
+	if (src_isvirt)
 		src = req->svirt;
 	else {
-		src = scratch->src;
+		src = NULL;
 		do {
 			if (acomp_request_src_isfolio(req)) {
 				spage = folio_page(req->sfolio, 0);
@@ -227,57 +237,39 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 				break;
 			src = kmap_local_page(spage) + soff;
 		} while (0);
-
-		if (src == scratch->src)
-			memcpy_from_sglist(scratch->src, req->src, 0, slen);
 	}
 
-	if (acomp_request_dst_isvirt(req))
-		dst = req->dvirt;
-	else {
-		unsigned int max = SCOMP_SCRATCH_SIZE;
+	stream = crypto_acomp_lock_stream_bh(&crypto_scomp_alg(scomp)->streams);
 
-		dst = scratch->dst;
-		do {
-			if (acomp_request_dst_isfolio(req)) {
-				dpage = folio_page(req->dfolio, 0);
-				doff = req->doff;
-			} else if (dlen <= req->dst->length) {
-				dpage = sg_page(req->dst);
-				doff = req->dst->offset;
-			} else
-				break;
+	if (!src_isvirt && !src) {
+		const u8 *src;
 
-			dpage = nth_page(dpage, doff / PAGE_SIZE);
-			doff = offset_in_page(doff);
+		scratch = scomp_lock_scratch();
+		src = scratch->src;
+		memcpy_from_sglist(scratch->src, req->src, 0, slen);
 
-			n = dlen / PAGE_SIZE;
-			n += (offset_in_page(dlen) + doff - 1) / PAGE_SIZE;
-			if (PageHighMem(dpage + n) &&
-			    size_add(doff, dlen) > PAGE_SIZE)
-				break;
-			dst = kmap_local_page(dpage) + doff;
-			max = dlen;
-		} while (0);
-		dlen = min(dlen, max);
-	}
+		if (dir)
+			ret = crypto_scomp_compress(scomp, src, slen,
+						    dst, &dlen, stream->ctx);
+		else
+			ret = crypto_scomp_decompress(scomp, src, slen,
+						      dst, &dlen, stream->ctx);
 
-	if (dir)
+		scomp_unlock_scratch(scratch);
+	} else if (dir)
 		ret = crypto_scomp_compress(scomp, src, slen,
 					    dst, &dlen, stream->ctx);
 	else
 		ret = crypto_scomp_decompress(scomp, src, slen,
 					      dst, &dlen, stream->ctx);
 
-	if (dst == scratch->dst)
-		memcpy_to_sglist(req->dst, 0, dst, dlen);
-
-	scomp_unlock_scratch(scratch);
 	crypto_acomp_unlock_stream_bh(stream);
 
 	req->dlen = dlen;
 
-	if (!acomp_request_dst_isvirt(req) && dst != scratch->dst) {
+	if (!src_isvirt && src)
+		kunmap_local(src);
+	if (!dst_isvirt) {
 		kunmap_local(dst);
 		dlen += doff;
 		for (;;) {
@@ -288,8 +280,6 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 			dpage = nth_page(dpage, 1);
 		}
 	}
-	if (!acomp_request_src_isvirt(req) && src != scratch->src)
-		kunmap_local(src);
 
 	return ret;
 }