[PATCH v1 08/12] boot: image: add weak hooks for the decompression buffer and flush

Add two weak hooks around the bootm image decompression:
image_get_decomp_buf() lets a platform redirect the decompression
destination (e.g. to an uncached window), and image_decomp_flush() lets
it flush the caches over the decompressed image. Both default to no-ops,
so existing platforms are unaffected. The EN75xx uses them to keep the
kernel coherent on its cache-coherent CM.

Signed-off-by: AK Sharma <[email protected]>
---
 boot/image.c    | 34 +++++++++++++++++++++++++++-------
 include/image.h |  5 +++++
 2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/boot/image.c b/boot/image.c
index 185d52ba..680a78da 100644
--- a/boot/image.c
+++ b/boot/image.c
@@ -442,15 +442,31 @@ int image_decomp_type(const unsigned char *buf, ulong len)
 	return cmagic->comp_id;
 }
 
+#if !defined(USE_HOSTCC)
+void *__weak image_get_decomp_buf(void *load_buf)
+{
+	return load_buf;
+}
+
+void __weak image_decomp_flush(ulong load, ulong image_len)
+{
+}
+#endif
+
 int image_decomp(int comp, ulong load, ulong image_start, int type,
 		 void *load_buf, void *image_buf, ulong image_len,
 		 uint unc_len, ulong *load_end)
 {
 	int ret = -ENOSYS;
+	void *dst = load_buf;
 
 	*load_end = load;
 	print_decomp_msg(comp, type, load == image_start, load);
 
+#if !defined(USE_HOSTCC)
+	dst = image_get_decomp_buf(load_buf);
+#endif
+
 	/*
 	 * Load the image to the right place, decompressing if needed. After
 	 * this, image_len will be set to the number of uncompressed bytes
@@ -462,13 +478,13 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 		if (load == image_start)
 			break;
 		if (image_len <= unc_len)
-			memmove_wd(load_buf, image_buf, image_len, CHUNKSZ);
+			memmove_wd(dst, image_buf, image_len, CHUNKSZ);
 		else
 			ret = -ENOSPC;
 		break;
 	case IH_COMP_GZIP:
 		if (!tools_build() && CONFIG_IS_ENABLED(GZIP))
-			ret = gunzip(load_buf, unc_len, image_buf, &image_len);
+			ret = gunzip(dst, unc_len, image_buf, &image_len);
 		break;
 	case IH_COMP_BZIP2:
 		if (!tools_build() && CONFIG_IS_ENABLED(BZIP2)) {
@@ -479,7 +495,7 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 			 * use slower decompression algorithm which requires
 			 * at most 2300 KB of memory.
 			 */
-			ret = BZ2_bzBuffToBuffDecompress(load_buf, &size,
+			ret = BZ2_bzBuffToBuffDecompress(dst, &size,
 				image_buf, image_len, CONSERVE_MEMORY, 0);
 			image_len = size;
 		}
@@ -488,7 +504,7 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 		if (!tools_build() && CONFIG_IS_ENABLED(LZMA)) {
 			SizeT lzma_len = unc_len;
 
-			ret = lzmaBuffToBuffDecompress(load_buf, &lzma_len,
+			ret = lzmaBuffToBuffDecompress(dst, &lzma_len,
 						       image_buf, image_len);
 			image_len = lzma_len;
 		}
@@ -497,7 +513,7 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 		if (!tools_build() && CONFIG_IS_ENABLED(LZO)) {
 			size_t size = unc_len;
 
-			ret = lzop_decompress(image_buf, image_len, load_buf, &size);
+			ret = lzop_decompress(image_buf, image_len, dst, &size);
 			image_len = size;
 		}
 		break;
@@ -505,7 +521,7 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 		if (!tools_build() && CONFIG_IS_ENABLED(LZ4)) {
 			size_t size = unc_len;
 
-			ret = ulz4fn(image_buf, image_len, load_buf, &size);
+			ret = ulz4fn(image_buf, image_len, dst, &size);
 			image_len = size;
 		}
 		break;
@@ -514,7 +530,7 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 			struct abuf in, out;
 
 			abuf_init_set(&in, image_buf, image_len);
-			abuf_init_set(&out, load_buf, unc_len);
+			abuf_init_set(&out, dst, unc_len);
 			ret = zstd_decompress(&in, &out);
 			if (ret >= 0) {
 				image_len = ret;
@@ -532,6 +548,10 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 	if (ret)
 		return ret;
 
+#if !defined(USE_HOSTCC)
+	image_decomp_flush(load, image_len);
+#endif
+
 	return 0;
 }
 
diff --git a/include/image.h b/include/image.h
index 34efac60..b2a6c536 100644
--- a/include/image.h
+++ b/include/image.h
@@ -1014,6 +1014,11 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
 		 void *load_buf, void *image_buf, ulong image_len,
 		 uint unc_len, ulong *load_end);
 
+#ifndef USE_HOSTCC
+void *image_get_decomp_buf(void *load_buf);
+void image_decomp_flush(ulong load, ulong image_len);
+#endif
+
 /**
  * Set up properties in the FDT
  *
-- 
2.53.0