[U-Boot] [PATCH] armv8: release slave cores from CPU_RELEASE_ADDR

[Oded Gabbay]

When using ARMv8 with ARMV8_SPIN_TABLE=y, we want the slave cores to
wait on spin_table_cpu_release_addr, until the Linux kernel will "wake" them
by writing to that location. The address of spin_table_cpu_release_addr is
transferred to the kernel using the device tree that is updated by
spin_table_update_dt().

However, if we also use SPL, then the slave cores are stuck at
CPU_RELEASE_ADDR instead and as a result, never wake up.

This patch releases the slave cores by writing spl_image->entry_point to
CPU_RELEASE_ADDR location before the end of the SPL code
(at jump_to_image_no_args()).

That way, the slave cores will start to execute the u-boot and will get to
the spin-table code and wait on the correct address
(spin_table_cpu_release_addr).

Signed-off-by: Oded Gabbay <oded.gabbay at gmail.com>
Cc: Simon Glass <sjg at chromium.org>
---
 common/spl/spl.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/common/spl/spl.c b/common/spl/spl.c
index f7df834..63d7db9 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -167,6 +167,14 @@ __weak void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image)
 		(image_entry_noargs_t)(unsigned long)spl_image->entry_point;
 
 	debug("image entry point: 0x%X\n", spl_image->entry_point);
+#if defined(CONFIG_ARMV8_SPIN_TABLE) && defined(CONFIG_ARMV8_MULTIENTRY)
+	/*
+	 * Release all slave cores from CPU_RELEASE_ADDR so they could
+	 * arrive to the spin-table code in start.S of the u-boot
+	 */
+	*(ulong *)CPU_RELEASE_ADDR = (ulong)spl_image->entry_point;
+#endif
+
 	image_entry();
 }
 
-- 
2.7.4