Merge patch series "Handoff bloblist from previous boot stage"

Raymond Mao <raymond.mao@linaro.org> says:

This patch set adds/adapts a few bloblist APIs and implements Arm arch
custom function to retrieve the bloblist (aka. Transfer List) from
previous loader via boot arguments when BLOBLIST option is enabled and
all boot arguments are compliant to the register conventions defined
in the Firmware Handoff spec v0.9.

If an arch wishes to have different behaviors for loading bloblist
from the previous boot stage, it is required to implement the custom
function xferlist_from_boot_arg().

10 files changed, 208 insertions, 40 deletions

diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 69e281b086a..7730a16e512 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -152,9 +152,38 @@ ENDPROC(c_runtime_cpu_setup)
  *
  *************************************************************************/
 WEAK(save_boot_params)
+#if (IS_ENABLED(CONFIG_BLOBLIST))
+	/* Calculate the PC-relative address of saved_args */
+	adr	r12, saved_args_offset
+	ldr	r13, saved_args_offset
+	add	r12, r12, r13
+
+	/*
+	 * Intentionally swapping r0 with r2 in order to simplify the C
+	 * function we use later.
+	 */
+	str	r2, [r12]
+	str	r1, [r12, #4]
+	str	r0, [r12, #8]
+	str	r3, [r12, #12]
+#endif
 	b	save_boot_params_ret		@ back to my caller
 ENDPROC(save_boot_params)
 
+#if (IS_ENABLED(CONFIG_BLOBLIST))
+saved_args_offset:
+	.long	saved_args - .	/* offset from current code to save_args */
+
+	.section .data
+	.align 2
+	.global saved_args
+saved_args:
+	.rept 4
+	.word 0
+	.endr
+END(saved_args)
+#endif
+
 #ifdef CONFIG_ARMV7_LPAE
 WEAK(switch_to_hypervisor)
 	b	switch_to_hypervisor_ret
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index 6cc1d26e5e2..74612802617 100644
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -370,5 +370,28 @@ ENTRY(c_runtime_cpu_setup)
 ENDPROC(c_runtime_cpu_setup)
 
 WEAK(save_boot_params)
+#if (IS_ENABLED(CONFIG_BLOBLIST))
+	/* Calculate the PC-relative address of saved_args */
+	adr	x9, saved_args_offset
+	ldr	w10, saved_args_offset
+	add	x9, x9, w10, sxtw
+
+	stp	x0, x1, [x9]
+	stp	x2, x3, [x9, #16]
+#endif
 	b	save_boot_params_ret	/* back to my caller */
 ENDPROC(save_boot_params)
+
+#if (IS_ENABLED(CONFIG_BLOBLIST))
+saved_args_offset:
+	.long	saved_args - .	/* offset from current code to save_args */
+
+	.section .data
+	.align 2
+	.global saved_args
+saved_args:
+	.rept 4
+	.dword 0
+	.endr
+END(saved_args)
+#endif
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index b1bcd374662..67275fba616 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -85,6 +85,8 @@ obj-y	+= psci-dt.o
 
 obj-$(CONFIG_DEBUG_LL)	+= debug.o
 
+obj-$(CONFIG_BLOBLIST)  += xferlist.o
+
 # For EABI conformant tool chains, provide eabi_compat()
 ifneq (,$(findstring -mabi=aapcs-linux,$(PLATFORM_CPPFLAGS)))
 extra-y	+= eabi_compat.o
diff --git a/arch/arm/lib/xferlist.c b/arch/arm/lib/xferlist.c
new file mode 100644
index 00000000000..f9c5d88bd47
--- /dev/null
+++ b/arch/arm/lib/xferlist.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Linaro Limited
+ * Author: Raymond Mao <raymond.mao@linaro.org>
+ */
+#include <linux/types.h>
+#include <errno.h>
+#include <bloblist.h>
+#include "xferlist.h"
+
+int xferlist_from_boot_arg(ulong addr, ulong size)
+{
+	int ret;
+
+	ret = bloblist_check(saved_args[3], size);
+	if (ret)
+		return ret;
+
+	ret = bloblist_check_reg_conv(saved_args[0], saved_args[2],
+				      saved_args[1]);
+	if (ret)
+		return ret;
+
+	return bloblist_reloc((void *)addr, size);
+}
diff --git a/arch/arm/lib/xferlist.h b/arch/arm/lib/xferlist.h
new file mode 100644
index 00000000000..60d79c1a8eb
--- /dev/null
+++ b/arch/arm/lib/xferlist.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ BSD-3-Clause */
+/*
+ * Copyright (C) 2023 Linaro Limited
+ * Author: Raymond Mao <raymond.mao@linaro.org>
+ */
+
+#ifndef _XFERLIST_H_
+#define _XFERLIST_H_
+
+/*
+ * Boot parameters saved from start.S
+ * saved_args[0]: FDT base address
+ * saved_args[1]: Bloblist signature
+ * saved_args[2]: must be 0
+ * saved_args[3]: Bloblist base address
+ */
+extern unsigned long saved_args[];
+
+#endif /* _XFERLIST_H_ */
diff --git a/common/bloblist.c b/common/bloblist.c
index 2d373910b6d..ad06d7a1795 100644
--- a/common/bloblist.c
+++ b/common/bloblist.c
@@ -384,7 +384,7 @@ int bloblist_check(ulong addr, uint size)
 		return log_msg_ret("Bad magic", -ENOENT);
 	if (hdr->version != BLOBLIST_VERSION)
 		return log_msg_ret("Bad version", -EPROTONOSUPPORT);
-	if (!hdr->total_size || (size && hdr->total_size != size))
+	if (!hdr->total_size || (size && hdr->total_size > size))
 		return log_msg_ret("Bad total size", -EFBIG);
 	if (hdr->used_size > hdr->total_size)
 		return log_msg_ret("Bad used size", -ENOENT);
@@ -472,13 +472,28 @@ void bloblist_show_list(void)
 	}
 }
 
-void bloblist_reloc(void *to, uint to_size, void *from, uint from_size)
+int bloblist_reloc(void *to, uint to_size)
 {
 	struct bloblist_hdr *hdr;
 
-	memcpy(to, from, from_size);
+	if (to_size < gd->bloblist->total_size)
+		return -ENOSPC;
+
+	memcpy(to, gd->bloblist, gd->bloblist->total_size);
 	hdr = to;
 	hdr->total_size = to_size;
+	gd->bloblist = to;
+
+	return 0;
+}
+
+/*
+ * Weak default function for getting bloblist from boot args.
+ */
+int __weak xferlist_from_boot_arg(ulong __always_unused addr,
+				  ulong __always_unused size)
+{
+	return -ENOENT;
 }
 
 int bloblist_init(void)
@@ -486,32 +501,43 @@ int bloblist_init(void)
 	bool fixed = IS_ENABLED(CONFIG_BLOBLIST_FIXED);
 	int ret = -ENOENT;
 	ulong addr, size;
-	bool expected;
-
-	/**
-	 * We don't expect to find an existing bloblist in the first phase of
-	 * U-Boot that runs. Also we have no way to receive the address of an
-	 * allocated bloblist from a previous stage, so it must be at a fixed
+	/*
+	 * If U-Boot is not in the first phase, an existing bloblist must be
+	 * at a fixed address.
+	 */
+	bool from_addr = fixed && !u_boot_first_phase();
+	/*
+	 * If U-Boot is in the first phase that an arch custom routine should
+	 * install the bloblist passed from previous loader to this fixed
 	 * address.
 	 */
-	expected = fixed && !u_boot_first_phase();
+	bool from_boot_arg = fixed && u_boot_first_phase();
+
 	if (spl_prev_phase() == PHASE_TPL && !IS_ENABLED(CONFIG_TPL_BLOBLIST))
-		expected = false;
+		from_addr = false;
 	if (fixed)
 		addr = IF_ENABLED_INT(CONFIG_BLOBLIST_FIXED,
 				      CONFIG_BLOBLIST_ADDR);
 	size = CONFIG_BLOBLIST_SIZE;
-	if (expected) {
+
+	if (from_boot_arg)
+		ret = xferlist_from_boot_arg(addr, size);
+	else if (from_addr)
 		ret = bloblist_check(addr, size);
-		if (ret) {
-			log_warning("Expected bloblist at %lx not found (err=%d)\n",
-				    addr, ret);
-		} else {
-			/* Get the real size, if it is not what we expected */
-			size = gd->bloblist->total_size;
-		}
-	}
+
+	if (ret)
+		log_warning("Bloblist at %lx not found (err=%d)\n",
+			    addr, ret);
+	else
+		/* Get the real size */
+		size = gd->bloblist->total_size;
+
 	if (ret) {
+		/*
+		 * If we don't have a bloblist from a fixed address, or the one
+		 * in the fixed address is not valid. we must allocate the
+		 * memory for it now.
+		 */
 		if (CONFIG_IS_ENABLED(BLOBLIST_ALLOC)) {
 			void *ptr = memalign(BLOBLIST_ALIGN, size);
 
@@ -519,7 +545,8 @@ int bloblist_init(void)
 				return log_msg_ret("alloc", -ENOMEM);
 			addr = map_to_sysmem(ptr);
 		} else if (!fixed) {
-			return log_msg_ret("!fixed", ret);
+			return log_msg_ret("BLOBLIST_FIXED is not enabled",
+					   ret);
 		}
 		log_debug("Creating new bloblist size %lx at %lx\n", size,
 			  addr);
@@ -532,6 +559,11 @@ int bloblist_init(void)
 		return log_msg_ret("ini", ret);
 	gd->flags |= GD_FLG_BLOBLIST_READY;
 
+#ifdef DEBUG
+	bloblist_show_stats();
+	bloblist_show_list();
+#endif
+
 	return 0;
 }
 
@@ -542,3 +574,14 @@ int bloblist_maybe_init(void)
 
 	return 0;
 }
+
+int bloblist_check_reg_conv(ulong rfdt, ulong rzero, ulong rsig)
+{
+	if (rzero || rsig != (BLOBLIST_MAGIC | BLOBLIST_REGCONV_VER) ||
+	    rfdt != (ulong)bloblist_find(BLOBLISTT_CONTROL_FDT, 0)) {
+		gd->bloblist = NULL;  /* Reset the gd bloblist pointer */
+		return -EIO;
+	}
+
+	return 0;
+}
diff --git a/common/board_f.c b/common/board_f.c
index 442b8349d08..7e313691028 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -706,13 +706,10 @@ static int reloc_bloblist(void)
 		return 0;
 	}
 	if (gd->new_bloblist) {
-		int size = CONFIG_BLOBLIST_SIZE;
-
 		debug("Copying bloblist from %p to %p, size %x\n",
-		      gd->bloblist, gd->new_bloblist, size);
-		bloblist_reloc(gd->new_bloblist, CONFIG_BLOBLIST_SIZE_RELOC,
-			       gd->bloblist, size);
-		gd->bloblist = gd->new_bloblist;
+		      gd->bloblist, gd->new_bloblist, gd->bloblist->total_size);
+		return bloblist_reloc(gd->new_bloblist,
+				      CONFIG_BLOBLIST_SIZE_RELOC);
 	}
 #endif
 
diff --git a/dts/Kconfig b/dts/Kconfig
index 00c0aeff893..def0e172412 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -121,6 +121,7 @@ config OF_BOARD
 
 config OF_HAS_PRIOR_STAGE
 	bool
+	depends on !BLOBLIST
 	help
 	  Indicates that a prior stage of the firmware (before U-Boot proper)
 	  makes use of device tree and this board normally boots with that prior
diff --git a/include/bloblist.h b/include/bloblist.h
index 84fc9438191..7fbdd622bcf 100644
--- a/include/bloblist.h
+++ b/include/bloblist.h
@@ -78,6 +78,13 @@ enum {
 	BLOBLIST_VERSION	= 1,
 	BLOBLIST_MAGIC		= 0x4a0fb10b,
 
+	/*
+	 * FIXME:
+	 * Register convention version should be placed into a higher byte
+	 * https://github.com/FirmwareHandoff/firmware_handoff/issues/32
+	 */
+	BLOBLIST_REGCONV_VER	= 1 << 24,
+
 	BLOBLIST_BLOB_ALIGN_LOG2 = 3,
 	BLOBLIST_BLOB_ALIGN	 = 1 << BLOBLIST_BLOB_ALIGN_LOG2,
 
@@ -341,12 +348,13 @@ int bloblist_new(ulong addr, uint size, uint flags, uint align_log2);
  * bloblist_check() - Check if a bloblist exists
  *
  * @addr: Address of bloblist
- * @size: Expected size of blobsize, or 0 to detect the size
+ * @size: Reserved space size for blobsize, or 0 to use the total size
  * Return: 0 if OK, -ENOENT if the magic number doesn't match (indicating that
- * there problem is no bloblist at the given address), -EPROTONOSUPPORT
+ * there problem is no bloblist at the given address) or any fields for header
+ * size, used size and total size do not match, -EPROTONOSUPPORT
  * if the version does not match, -EIO if the checksum does not match,
- * -EFBIG if the expected size does not match the detected size, -ENOSPC
- * if the size is not large enough to hold the headers
+ * -EFBIG if the reserved space size is small than the total size or total size
+ * is 0
  */
 int bloblist_check(ulong addr, uint size);
 
@@ -418,11 +426,11 @@ const char *bloblist_tag_name(enum bloblist_tag_t tag);
  * bloblist_reloc() - Relocate the bloblist and optionally resize it
  *
  * @to: Pointer to new bloblist location (must not overlap old location)
- * @to_size: New size for bloblist (must be larger than from_size)
- * @from: Pointer to bloblist to relocate
- * @from_size: Size of bloblist to relocate
+ * @to_size: New size for bloblist
+ * Return: 0 if OK, -ENOSPC if the new size is small than the bloblist total
+ *	   size.
  */
-void bloblist_reloc(void *to, uint to_size, void *from, uint from_size);
+int bloblist_reloc(void *to, uint to_size);
 
 /**
  * bloblist_init() - Init the bloblist system with a single bloblist
@@ -461,4 +469,27 @@ static inline int bloblist_maybe_init(void)
 }
 #endif /* BLOBLIST */
 
+/**
+ * bloblist_check_reg_conv() - Check whether the bloblist is compliant to
+ *			       the register conventions according to the
+ *			       Firmware Handoff spec.
+ *
+ * @rfdt:  Register that holds the FDT base address.
+ * @rzero: Register that must be zero.
+ * @rsig:  Register that holds signature and register conventions version.
+ * Return: 0 if OK, -EIO if the bloblist is not compliant to the register
+ *	   conventions.
+ */
+int bloblist_check_reg_conv(ulong rfdt, ulong rzero, ulong rsig);
+
+/**
+ * xferlist_from_boot_arg() - Get bloblist from the boot args and relocate it
+ *			      to the specified address.
+ *
+ * @addr: Address for the bloblist
+ * @size: Size of space reserved for the bloblist
+ * Return: 0 if OK, else on error
+ */
+int xferlist_from_boot_arg(ulong addr, ulong size);
+
 #endif /* __BLOBLIST_H */
diff --git a/test/bloblist.c b/test/bloblist.c
index 17d9dd03d07..1c60bbac36c 100644
--- a/test/bloblist.c
+++ b/test/bloblist.c
@@ -207,7 +207,7 @@ static int bloblist_test_checksum(struct unit_test_state *uts)
 	hdr->flags++;
 
 	hdr->total_size--;
-	ut_asserteq(-EFBIG, bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
+	ut_asserteq(-EIO, bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
 	hdr->total_size++;
 
 	hdr->spare++;
@@ -376,13 +376,12 @@ static int bloblist_test_reloc(struct unit_test_state *uts)
 {
 	const uint large_size = TEST_BLOBLIST_SIZE;
 	const uint small_size = 0x20;
-	void *old_ptr, *new_ptr;
+	void *new_ptr;
 	void *blob1, *blob2;
 	ulong new_addr;
 	ulong new_size;
 
 	ut_assertok(bloblist_new(TEST_ADDR, TEST_BLOBLIST_SIZE, 0, 0));
-	old_ptr = map_sysmem(TEST_ADDR, TEST_BLOBLIST_SIZE);
 
 	/* Add one blob and then one that won't fit */
 	blob1 = bloblist_add(TEST_TAG, small_size, 0);
@@ -394,8 +393,7 @@ static int bloblist_test_reloc(struct unit_test_state *uts)
 	new_addr = TEST_ADDR + TEST_BLOBLIST_SIZE;
 	new_size = TEST_BLOBLIST_SIZE + 0x100;
 	new_ptr = map_sysmem(new_addr, TEST_BLOBLIST_SIZE);
-	bloblist_reloc(new_ptr, new_size, old_ptr, TEST_BLOBLIST_SIZE);
-	gd->bloblist = new_ptr;
+	ut_assertok(bloblist_reloc(new_ptr, new_size));
 
 	/* Check the old blob is there and that we can now add the bigger one */
 	ut_assertnonnull(bloblist_find(TEST_TAG, small_size));