Adding upstream version 2.8.0+dfsg.upstream/2.8.0+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/plat/allwinner/common/arisc_off.S b/plat/allwinner/common/arisc_off.S
new file mode 100644
index 0000000..ed10832
--- /dev/null
+++ b/plat/allwinner/common/arisc_off.S
@@ -0,0 +1,115 @@
+# turn_off_core.S
+#
+# Copyright (c) 2018, Andre Przywara <osp@andrep.de>
+# SPDX-License-Identifier: BSD-3-Clause
+#
+# OpenRISC assembly to turn off an ARM core on an Allwinner SoC from
+# the arisc management controller.
+# Generate a binary representation with:
+# $ or1k-elf-as -c -o turn_off_core.o turn_off_core.S
+# $ or1k-elf-objcopy -O binary --reverse-bytes=4 turn_off_core.o \
+#   turn_off_core.bin
+# The encoded instructions go into an array defined in
+# plat/allwinner/sun50i_*/include/core_off_arisc.h, to be handed off to
+# the arisc processor.
+#
+# This routine is meant to be called directly from arisc reset (put the
+# start address in the reset vector), to be actually triggered by that
+# very ARM core to be turned off.
+# It expects the core number presented as a mask in the upper half of
+# r3, so to be patched in the lower 16 bits of the first instruction,
+# overwriting the 0 in this code here.
+# The code will do the following:
+# - Read the C_CPU_STATUS register, which contains the status of the WFI
+#   lines of each of the four A53 cores.
+# - Loop until the core in question reaches WFI.
+# - Using that mask, activate the core output clamps by setting the
+#   respective core bit in CPUX_PWROFF_GATING_REG (0x1f01500).
+#   Note that the clamp for core 0 covers more than just the core, activating
+#   it hangs the whole system. So we skip this step for core 0.
+# - Using the negated mask, assert the core's reset line by clearing the
+#   respective bit in C_RST_CTRL (0x1f01c30).
+# - Finally turn off the core's power switch by writing 0xff to the
+#   respective CPUx_PWR_SWITCH_REG (0x1f01540 ff.)
+# - Assert the arisc's own reset to end execution.
+#   This also signals other arisc users that the chip is free again.
+# So in C this would look like:
+#	while (!(readl(0x1700030) & (1U << core_nr)))
+#		;
+#	if (core_nr != 0)
+#		writel(readl(0x1f01500) | (1U << core_nr), 0x1f01500);
+#	writel(readl(0x1f01c30) & ~(1U << core_nr), 0x1f01c30);
+#	writel(0xff, 0x1f01540 + (core_nr * 4));
+# (using A64/H5 addresses)
+
+.text
+_start:
+	l.movhi	r3, 0				# FIXUP! with core mask
+	l.movhi r0, 0				# clear r0
+	l.movhi	r13, 0x170			# r13: CPU_CFG_BASE=0x01700000
+wait_wfi:
+	l.lwz	r5, 0x30(r13)			# load C_CPU_STATUS
+	l.and	r5, r5, r3			# mask requested core
+	l.sfeq	r5, r0				# is it not yet in WFI?
+	l.bf	wait_wfi			# try again
+
+	l.srli	r6, r3, 16			# move mask to lower 16 bits
+	l.sfeqi	r6, 1				# core 0 is special
+	l.bf	1f				# don't touch the bit for core 0
+	l.movhi	r13, 0x1f0			# address of R_CPUCFG (delay)
+	l.lwz	r5, 0x1500(r13)			# core output clamps
+	l.or	r5, r5, r6			# set bit to ...
+	l.sw	0x1500(r13), r5			# ... activate for our core
+
+1:	l.lwz	r5, 0x1c30(r13)			# CPU power-on reset
+	l.xori	r6, r6, -1			# negate core mask
+	l.and	r5, r5, r6			# clear bit to ...
+	l.sw	0x1c30(r13), r5			# ... assert for our core
+
+	l.ff1	r6, r3				# get core number from high mask
+	l.addi	r6, r6, -17			# convert to 0-3
+	l.slli	r6, r6, 2			# r5: core number*4 (0-12)
+	l.add	r6, r6, r13			# add to base address
+	l.ori	r5, r0, 0xff			# 0xff means all switches off
+	l.sw	0x1540(r6), r5			# core power switch registers
+
+reset:	l.sw	0x1c00(r13),r0			# pull down our own reset line
+
+	l.j	reset				# just in case ....
+	l.nop	0x0				# (delay slot)
+
+# same as above, but with the MMIO addresses matching the H6 SoC
+_start_h6:
+	l.movhi	r3, 0				# FIXUP! with core mask
+	l.movhi r0, 0				# clear r0
+	l.movhi	r13, 0x901			# r13: CPU_CFG_BASE=0x09010000
+1:
+	l.lwz	r5, 0x80(r13)			# load C_CPU_STATUS
+	l.and	r5, r5, r3			# mask requested core
+	l.sfeq	r5, r0				# is it not yet in WFI?
+	l.bf	1b				# try again
+
+	l.srli	r6, r3, 16			# move mask to lower 16 bits(ds)
+	l.sfeqi	r6, 1				# core 0 is special
+	l.bf	1f				# don't touch the bit for core 0
+	l.movhi	r13, 0x700			# address of R_CPUCFG (ds)
+	l.lwz	r5, 0x0444(r13)			# core output clamps
+	l.or	r5, r5, r6			# set bit to ...
+	l.sw	0x0444(r13), r5			# ... activate for our core
+
+1:	l.lwz	r5, 0x0440(r13)			# CPU power-on reset
+	l.xori	r6, r6, -1			# negate core mask
+	l.and	r5, r5, r6			# clear bit to ...
+	l.sw	0x0440(r13), r5			# ... assert for our core
+
+	l.ff1	r6, r3				# get core number from high mask
+	l.addi	r6, r6, -17			# convert to 0-3
+	l.slli	r6, r6, 2			# r5: core number*4 (0-12)
+	l.add	r6, r6, r13			# add to base address
+	l.ori	r5, r0, 0xff			# 0xff means all switches off
+	l.sw	0x0450(r6), r5			# core power switch registers
+
+1:	l.sw	0x0400(r13),r0			# pull down our own reset line
+
+	l.j	1b				# just in case ...
+	l.nop	0x0				# (delay slot)