Add core support for a bloblist to convey data from SPL

At present there is no standard way in U-Boot to pass information from SPL
to U-Boot proper. But sometimes SPL wants to convey information to U-Boot
that U-Boot cannot easily figure out. For example, if SPL sets up SDRAM
then it might want to pass the size of SDRAM, or the location of each
bank, to U-Boot proper.

Add a new 'bloblist' feature which provides this. A bloblist is set up in
the first phase of U-Boot that runs (i.e. TPL or SPL). The location of
this info may be in SRAM or CAR (x86 cache-as-RAM) or somewhere else.

Information placed in this region is preserved (with a checksum) through
TPL and SPL and ends up in U-Boot. At this point it is copied into SDRAM
so it can be used after relocation.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Andreas Dannenberg <dannenberg@ti.com>

common/Kconfig

@@ -750,4 +750,52 @@ config UPDATE_TFTP_MSEC_MAX
 
 endmenu
 
+menu "Blob list"
+
+config BLOBLIST
+	bool "Support for a bloblist"
+	help
+	  This enables support for a bloblist in U-Boot, which can be passed
+	  from TPL to SPL to U-Boot proper (and potentially to Linux). The
+	  blob list supports multiple binary blobs of data, each with a tag,
+	  so that different U-Boot components can store data which can survive
+	  through to the next stage of the boot.
+
+config SPL_BLOBLIST
+	bool "Support for a bloblist in SPL"
+	depends on BLOBLIST
+	default y if SPL
+	help
+	  This enables a bloblist in SPL. If this is the first part of U-Boot
+	  to run, then the bloblist is set up in SPL and passed to U-Boot
+	  proper. If TPL also has a bloblist, then SPL uses the one from there.
+
+config TPL_BLOBLIST
+	bool "Support for a bloblist in TPL"
+	depends on BLOBLIST
+	default y if TPL
+	help
+	  This enables a bloblist in TPL. The bloblist is set up in TPL and
+	  passed to SPL and U-Boot proper.
+
+config BLOBLIST_SIZE
+	hex "Size of bloblist"
+	depends on BLOBLIST
+	default 0x400
+	help
+	  Sets the size of the bloblist in bytes. This must include all
+	  overhead (alignment, bloblist header, record header). The bloblist
+	  is set up in the first part of U-Boot to run (TPL, SPL or U-Boot
+	  proper), and this sane bloblist is used for subsequent stages.
+
+config BLOBLIST_ADDR
+	hex "Address of bloblist"
+	depends on BLOBLIST
+	default 0xe000 if SANDBOX
+	help
+	  Sets the address of the bloblist, set up by the first part of U-Boot
+	  which runs. Subsequent U-Boot stages typically use the same address.
+
+endmenu
+
 source "common/spl/Kconfig"

common/Makefile

@@ -61,6 +61,7 @@ obj-$(CONFIG_CMDLINE) += cli_readline.o cli_simple.o
 endif # !CONFIG_SPL_BUILD
 
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTAGE) += bootstage.o
+obj-$(CONFIG_$(SPL_TPL_)BLOBLIST) += bloblist.o
 
 ifdef CONFIG_SPL_BUILD
 ifdef CONFIG_SPL_DFU_SUPPORT

common/bloblist.c

@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <bloblist.h>
+#include <log.h>
+#include <mapmem.h>
+#include <spl.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct bloblist_rec *bloblist_first_blob(struct bloblist_hdr *hdr)
+{
+	if (hdr->alloced <= hdr->hdr_size)
+		return NULL;
+	return (struct bloblist_rec *)((void *)hdr + hdr->hdr_size);
+}
+
+struct bloblist_rec *bloblist_next_blob(struct bloblist_hdr *hdr,
+					struct bloblist_rec *rec)
+{
+	ulong offset;
+
+	offset = (void *)rec - (void *)hdr;
+	offset += rec->hdr_size + ALIGN(rec->size, BLOBLIST_ALIGN);
+	if (offset >= hdr->alloced)
+		return NULL;
+	return (struct bloblist_rec *)((void *)hdr + offset);
+}
+
+#define foreach_rec(_rec, _hdr) \
+	for (_rec = bloblist_first_blob(_hdr); \
+	     _rec; \
+	     _rec = bloblist_next_blob(_hdr, _rec))
+
+static struct bloblist_rec *bloblist_findrec(uint tag)
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+	struct bloblist_rec *rec;
+
+	if (!hdr)
+		return NULL;
+
+	foreach_rec(rec, hdr) {
+		if (rec->tag == tag)
+			return rec;
+	}
+
+	return NULL;
+}
+
+static int bloblist_addrec(uint tag, int size, struct bloblist_rec **recp)
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+	struct bloblist_rec *rec;
+	int new_alloced;
+
+	new_alloced = hdr->alloced + sizeof(*rec) +
+			ALIGN(size, BLOBLIST_ALIGN);
+	if (new_alloced >= hdr->size) {
+		log(LOGC_BLOBLIST, LOGL_ERR,
+		    "Failed to allocate %x bytes size=%x, need size>=%x\n",
+		    size, hdr->size, new_alloced);
+		return log_msg_ret("bloblist add", -ENOSPC);
+	}
+	rec = (void *)hdr + hdr->alloced;
+	hdr->alloced = new_alloced;
+
+	rec->tag = tag;
+	rec->hdr_size = sizeof(*rec);
+	rec->size = size;
+	rec->spare = 0;
+	*recp = rec;
+
+	return 0;
+}
+
+static int bloblist_ensurerec(uint tag, struct bloblist_rec **recp, int size)
+{
+	struct bloblist_rec *rec;
+
+	rec = bloblist_findrec(tag);
+	if (rec) {
+		if (size && size != rec->size)
+			return -ESPIPE;
+	} else {
+		int ret;
+
+		ret = bloblist_addrec(tag, size, &rec);
+		if (ret)
+			return ret;
+	}
+	*recp = rec;
+
+	return 0;
+}
+
+void *bloblist_find(uint tag, int size)
+{
+	struct bloblist_rec *rec;
+
+	rec = bloblist_findrec(tag);
+	if (!rec)
+		return NULL;
+	if (size && size != rec->size)
+		return NULL;
+
+	return (void *)rec + rec->hdr_size;
+}
+
+void *bloblist_add(uint tag, int size)
+{
+	struct bloblist_rec *rec;
+
+	if (bloblist_addrec(tag, size, &rec))
+		return NULL;
+
+	return rec + 1;
+}
+
+int bloblist_ensure_size(uint tag, int size, void **blobp)
+{
+	struct bloblist_rec *rec;
+	int ret;
+
+	ret = bloblist_ensurerec(tag, &rec, size);
+	if (ret)
+		return ret;
+	*blobp = (void *)rec + rec->hdr_size;
+
+	return 0;
+}
+
+void *bloblist_ensure(uint tag, int size)
+{
+	struct bloblist_rec *rec;
+
+	if (bloblist_ensurerec(tag, &rec, size))
+		return NULL;
+
+	return (void *)rec + rec->hdr_size;
+}
+
+static u32 bloblist_calc_chksum(struct bloblist_hdr *hdr)
+{
+	struct bloblist_rec *rec;
+	u32 chksum;
+
+	chksum = crc32(0, (unsigned char *)hdr,
+		       offsetof(struct bloblist_hdr, chksum));
+	foreach_rec(rec, hdr) {
+		chksum = crc32(chksum, (void *)rec, rec->hdr_size);
+		chksum = crc32(chksum, (void *)rec + rec->hdr_size, rec->size);
+	}
+
+	return chksum;
+}
+
+int bloblist_new(ulong addr, uint size, uint flags)
+{
+	struct bloblist_hdr *hdr;
+
+	if (size < sizeof(*hdr))
+		return log_ret(-ENOSPC);
+	if (addr & (BLOBLIST_ALIGN - 1))
+		return log_ret(-EFAULT);
+	hdr = map_sysmem(addr, size);
+	memset(hdr, '\0', sizeof(*hdr));
+	hdr->version = BLOBLIST_VERSION;
+	hdr->hdr_size = sizeof(*hdr);
+	hdr->flags = flags;
+	hdr->magic = BLOBLIST_MAGIC;
+	hdr->size = size;
+	hdr->alloced = hdr->hdr_size;
+	hdr->chksum = 0;
+	gd->bloblist = hdr;
+
+	return 0;
+}
+
+int bloblist_check(ulong addr, uint size)
+{
+	struct bloblist_hdr *hdr;
+	u32 chksum;
+
+	hdr = map_sysmem(addr, sizeof(*hdr));
+	if (hdr->magic != BLOBLIST_MAGIC)
+		return log_msg_ret("Bad magic", -ENOENT);
+	if (hdr->version != BLOBLIST_VERSION)
+		return log_msg_ret("Bad version", -EPROTONOSUPPORT);
+	if (size && hdr->size != size)
+		return log_msg_ret("Bad size", -EFBIG);
+	chksum = bloblist_calc_chksum(hdr);
+	if (hdr->chksum != chksum) {
+		log(LOGC_BLOBLIST, LOGL_ERR, "Checksum %x != %x\n", hdr->chksum,
+		    chksum);
+		return log_msg_ret("Bad checksum", -EIO);
+	}
+	gd->bloblist = hdr;
+
+	return 0;
+}
+
+int bloblist_finish(void)
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+
+	hdr->chksum = bloblist_calc_chksum(hdr);
+
+	return 0;
+}
+
+int bloblist_init(void)
+{
+	bool expected;
+	int ret = -ENOENT;
+
+	/**
+	 * Wed expect to find an existing bloblist in the first phase of U-Boot
+	 * that runs
+	 */
+	expected = !u_boot_first_phase();
+	if (expected)
+		ret = bloblist_check(CONFIG_BLOBLIST_ADDR,
+				     CONFIG_BLOBLIST_SIZE);
+	if (ret) {
+		log(LOGC_BLOBLIST, expected ? LOGL_WARNING : LOGL_DEBUG,
+		    "Existing bloblist not found: creating new bloblist\n");
+		ret = bloblist_new(CONFIG_BLOBLIST_ADDR, CONFIG_BLOBLIST_SIZE,
+				   0);
+	} else {
+		log(LOGC_BLOBLIST, LOGL_DEBUG, "Found existing bloblist\n");
+	}
+
+	return ret;
+}