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Date:      Thu, 4 Nov 2021 16:02:54 GMT
From:      Adrian Chadd <adrian@FreeBSD.org>
To:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org
Subject:   git: d3514c294207 - main - ipq401x: add MP core start-up path for the CPU regulator/clock gate used
Message-ID:  <202111041602.1A4G2sDd003734@gitrepo.freebsd.org>

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The branch main has been updated by adrian:

URL: https://cgit.FreeBSD.org/src/commit/?id=d3514c294207bd5cda7f4276ebff5235bb239b8a

commit d3514c294207bd5cda7f4276ebff5235bb239b8a
Author:     Adrian Chadd <adrian@FreeBSD.org>
AuthorDate: 2021-10-30 04:27:02 +0000
Commit:     Adrian Chadd <adrian@FreeBSD.org>
CommitDate: 2021-11-04 16:02:36 +0000

    ipq401x: add MP core start-up path for the CPU regulator/clock gate used
    
    This code implements the "kpssv2" flavour of CPU regulator/clock gating
    in Linux.  It's used by at least the ipq4018/4019 to power on and off
    CPU cores.
    
    This is based on the Linux implementation - the register definitions
    and values are from Linux and I've reverse engineered the sequencing
    requirements.
    
    The MP bring-up is:
    
    * set cold boot address via an SCM call - this is the address used
      by the bootloader/TZ firmware to jump to when the CPUs boot
    
    * power down the LDO feeding the CPU core and wait for it to settle
    
    * program in the right set of LDO and power tree configuration for
      the CPU regulator to power up the core.  Unfortunately these are
      magic numbers that I've not found documented anywhere.
    
    * (I think) power up the shared L2 cache connect if it isn't.
    
    * Clamp the power into the core down; put the core into reset
    
    * Unclamp the power rail; release reset; and then set the core to boot.
    
    The MP core will then boot the bootloader/TZ firmware and then
    will wait until an incoming interrupt kicks it to start @ mpentry.
    
    Tested:
    
    * IPQ4019, 4 CPUs
    
    Release APs
    CPU(3) applied BP hardening: not necessary
    CPU(1) applied BP hardening: not necessary
    CPU(2) applied BP hardening: not necessary
    
    Reviewed by: andrew, manu, imp
    Differential Revision: https://reviews.freebsd.org/D32723
---
 sys/arm/qualcomm/ipq4018_mp.c          |  55 +++++++++
 sys/arm/qualcomm/qcom_cpu_kpssv2.c     | 211 +++++++++++++++++++++++++++++++++
 sys/arm/qualcomm/qcom_cpu_kpssv2.h     |  35 ++++++
 sys/arm/qualcomm/qcom_cpu_kpssv2_reg.h |  58 +++++++++
 sys/arm/qualcomm/std.ipq4018           |   1 +
 5 files changed, 360 insertions(+)

diff --git a/sys/arm/qualcomm/ipq4018_mp.c b/sys/arm/qualcomm/ipq4018_mp.c
index 37b7cc3e097d..a7ebb7d7d6c8 100644
--- a/sys/arm/qualcomm/ipq4018_mp.c
+++ b/sys/arm/qualcomm/ipq4018_mp.c
@@ -35,27 +35,82 @@ __FBSDID("$FreeBSD$");
 #include <sys/bus.h>
 #include <sys/reboot.h>
 #include <sys/devmap.h>
+#include <sys/smp.h>
 
 #include <vm/vm.h>
 
+#include <machine/cpu.h>
 #include <machine/bus.h>
 #include <machine/intr.h>
 #include <machine/machdep.h>
 #include <machine/platformvar.h>
+#include <machine/smp.h>
 
 #include <dev/fdt/fdt_common.h>
 #include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_cpu.h>
 
 #include <arm/qualcomm/ipq4018_machdep.h>
+#include <arm/qualcomm/qcom_scm_legacy.h>
+#include <arm/qualcomm/qcom_cpu_kpssv2.h>
 
 #include "platform_if.h"
 
 void
 ipq4018_mp_setmaxid(platform_t plat)
 {
+	int ncpu;
+
+	/* If we've already set the global vars don't bother to do it again. */
+	if (mp_ncpus != 0)
+		return;
+
+	/* Read current CP15 Cache Size ID Register */
+	ncpu = cp15_l2ctlr_get();
+	ncpu = CPUV7_L2CTLR_NPROC(ncpu);
+
+	mp_ncpus = ncpu;
+	mp_maxid = ncpu - 1;
+
+	printf("SMP: ncpu=%d\n", ncpu);
+}
+
+static boolean_t
+ipq4018_start_ap(u_int id, phandle_t node, u_int addr_cells, pcell_t *arg)
+{
+
+	/*
+	 * For the IPQ401x we assume the enable method is
+	 * "qcom,kpss-acc-v2".  If this path gets turned into
+	 * something more generic for other 32 bit qualcomm
+	 * SoCs then we'll likely want to turn this into a
+	 * switch based on "enable-method".
+	 */
+	return qcom_cpu_kpssv2_regulator_start(id, node);
 }
 
 void
 ipq4018_mp_start_ap(platform_t plat)
 {
+	int ret;
+
+	/*
+	 * First step - SCM call to set the cold boot address to mpentry, so
+	 * CPUs hopefully start in the MP path.
+	 */
+	ret = qcom_scm_legacy_mp_set_cold_boot_address((vm_offset_t) mpentry);
+	if (ret != 0)
+		panic("%s: Couldn't set cold boot address via SCM "
+		    "(error 0x%08x)", __func__, ret);
+
+	/*
+	 * Next step - loop over the CPU nodes and do the per-CPU setup
+	 * required to power on the CPUs themselves.
+	 */
+	ofw_cpu_early_foreach(ipq4018_start_ap, true);
+
+	/*
+	 * The next set of IPIs to the CPUs will wake them up and enter
+	 * mpentry.
+	 */
 }
diff --git a/sys/arm/qualcomm/qcom_cpu_kpssv2.c b/sys/arm/qualcomm/qcom_cpu_kpssv2.c
new file mode 100644
index 000000000000..4193f952549b
--- /dev/null
+++ b/sys/arm/qualcomm/qcom_cpu_kpssv2.c
@@ -0,0 +1,211 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "opt_platform.h"
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/reboot.h>
+#include <sys/devmap.h>
+#include <sys/smp.h>
+
+#include <vm/vm.h>
+
+#include <machine/cpu.h>
+#include <machine/bus.h>
+#include <machine/intr.h>
+#include <machine/machdep.h>
+#include <machine/platformvar.h>
+#include <machine/smp.h>
+
+#include <dev/fdt/fdt_common.h>
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_cpu.h>
+
+#include <arm/qualcomm/qcom_cpu_kpssv2_reg.h>
+#include <arm/qualcomm/qcom_cpu_kpssv2.h>
+
+#include "platform_if.h"
+
+/*
+ * Since DELAY() hangs this early, we need some way to
+ * delay things to settle.
+ */
+static inline void
+loop_delay(int usec)
+{
+	int lcount = usec * 100000;
+
+	for (volatile int i = 0; i < lcount; i++)
+		;
+}
+
+/*
+ * This is the KPSSv2 (eg IPQ4018) regulator path for CPU
+ * and shared L2 cache power-on.
+ */
+boolean_t
+qcom_cpu_kpssv2_regulator_start(u_int id, phandle_t node)
+{
+	phandle_t acc_phandle, l2_phandle, saw_phandle;
+	bus_space_tag_t acc_tag, saw_tag;
+	bus_space_handle_t acc_handle, saw_handle;
+	bus_size_t acc_sz, saw_sz;
+	ssize_t sret;
+	int ret;
+	uint32_t reg_val;
+
+	/*
+	 * We don't need to power up CPU 0!  This will power it
+	 * down first and ... then everything hangs.
+	 */
+	if (id == 0)
+		return true;
+
+	/*
+	 * Walk the qcom,acc and next-level-cache entries to find their
+	 * child phandles and thus regulators.
+	 *
+	 * The qcom,acc is a phandle to a node.
+	 *
+	 * The next-level-cache actually is a phandle through to a qcom,saw
+	 * entry.
+	 */
+	sret = OF_getencprop(node, "qcom,acc", (void *) &acc_phandle,
+	    sizeof(acc_phandle));
+	if (sret != sizeof(acc_phandle))
+		panic("***couldn't get phandle for qcom,acc");
+	acc_phandle = OF_node_from_xref(acc_phandle);
+
+	sret = OF_getencprop(node, "next-level-cache", (void *) &l2_phandle,
+	    sizeof(l2_phandle));
+	if (sret != sizeof(l2_phandle))
+		panic("***couldn't get phandle for next-level-cache");
+	l2_phandle = OF_node_from_xref(l2_phandle);
+
+	sret = OF_getencprop(l2_phandle, "qcom,saw", (void *) &saw_phandle,
+	    sizeof(saw_phandle));
+	if (sret != sizeof(saw_phandle))
+		panic("***couldn't get phandle for qcom,saw");
+	l2_phandle = OF_node_from_xref(l2_phandle);
+
+	/*
+	 * Now that we have the phandles referencing the correct locations,
+	 * do some KVA mappings so we can go access the registers.
+	 */
+	ret = OF_decode_addr(acc_phandle, 0, &acc_tag, &acc_handle, &acc_sz);
+	if (ret != 0)
+		panic("*** couldn't map qcom,acc space (%d)", ret);
+	ret = OF_decode_addr(saw_phandle, 0, &saw_tag, &saw_handle, &saw_sz);
+	if (ret != 0)
+		panic("*** couldn't map next-level-cache -> "
+		    "qcom,saw space (%d)", ret);
+
+	/*
+	 * Power sequencing to ensure the cores are off, then power them on
+	 * and bring them out of reset.
+	 */
+
+	/*
+	 * BHS: off
+	 * LDO: bypassed, powered off
+	 */
+	reg_val = (64 << QCOM_APC_PWR_GATE_CTL_BHS_CNT_SHIFT)
+	    | (0x3f << QCOM_APC_PWR_GATE_CTL_LDO_PWR_DWN_SHIFT)
+	    | QCOM_APC_PWR_GATE_CTL_BHS_EN;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
+	mb();
+	/* Settle time */
+	loop_delay(1);
+
+	/*
+	 * Start up BHS segments.
+	 */
+	reg_val |= 0x3f << QCOM_APC_PWR_GATE_CTL_BHS_SEG_SHIFT;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
+	mb();
+	/* Settle time */
+	loop_delay(1);
+
+	/*
+	 * Switch on the LDO bypass; BHS will now supply power.
+	 */
+	reg_val |= 0x3f << QCOM_APC_PWR_GATE_CTL_LDO_BYP_SHIFT;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APC_PWR_GATE_CTL, reg_val);
+
+	/*
+	 * Shared L2 regulator control.
+	 */
+	bus_space_write_4(saw_tag, saw_handle, QCOM_APCS_SAW2_2_VCTL, 0x10003);
+	mb();
+	/* Settle time */
+	loop_delay(50);
+
+	/*
+	 * Put the core in reset.
+	 */
+	reg_val = QCOM_APCS_CPU_PWR_CTL_COREPOR_RST
+	    | QCOM_APCS_CPU_PWR_CTL_CLAMP;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
+	mb();
+	loop_delay(2);
+
+	/*
+	 * Remove power-down clamp.
+	 */
+	reg_val &= ~QCOM_APCS_CPU_PWR_CTL_CLAMP;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
+	mb();
+	loop_delay(2);
+
+	/*
+	 * Clear core power reset.
+	 */
+	reg_val &= ~QCOM_APCS_CPU_PWR_CTL_COREPOR_RST;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
+	mb();
+
+	/*
+	 * The power is ready, the core is out of reset, signal the core
+	 * to power up.
+	 */
+	reg_val |= QCOM_APCS_CPU_PWR_CTL_CORE_PWRD_UP;
+	bus_space_write_4(acc_tag, acc_handle, QCOM_APCS_CPU_PWR_CTL, reg_val);
+	mb();
+
+	/*
+	 * Finished with these KVA mappings, so release them.
+	 */
+	bus_space_unmap(acc_tag, acc_handle, acc_sz);
+	bus_space_unmap(saw_tag, saw_handle, saw_sz);
+
+	return true;
+}
diff --git a/sys/arm/qualcomm/qcom_cpu_kpssv2.h b/sys/arm/qualcomm/qcom_cpu_kpssv2.h
new file mode 100644
index 000000000000..18e4affc208e
--- /dev/null
+++ b/sys/arm/qualcomm/qcom_cpu_kpssv2.h
@@ -0,0 +1,35 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	__QCOM_CPU_KPSSV2_H__
+#define	__QCOM_CPU_KPSSV2_H__
+
+extern	boolean_t qcom_cpu_kpssv2_regulator_start(u_int id, phandle_t node);
+
+#endif	/* __QCOM_CPU_KPSSV2_H__ */
diff --git a/sys/arm/qualcomm/qcom_cpu_kpssv2_reg.h b/sys/arm/qualcomm/qcom_cpu_kpssv2_reg.h
new file mode 100644
index 000000000000..b966571e9fdd
--- /dev/null
+++ b/sys/arm/qualcomm/qcom_cpu_kpssv2_reg.h
@@ -0,0 +1,58 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	__QCOM_CPU_KPSSV2_REG_H__
+#define	__QCOM_CPU_KPSSV2_REG_H__
+
+
+/*
+ * APCS CPU core regulator registers.
+ */
+#define	QCOM_APCS_CPU_PWR_CTL				0x04
+#define		QCOM_APCS_CPU_PWR_CTL_PLL_CLAMP		(1U << 8)
+#define		QCOM_APCS_CPU_PWR_CTL_CORE_PWRD_UP	(1U << 7)
+#define		QCOM_APCS_CPU_PWR_CTL_COREPOR_RST	(1U << 5)
+#define		QCOM_APCS_CPU_PWR_CTL_CORE_RST		(1U << 4)
+#define		QCOM_APCS_CPU_PWR_CTL_L2DT_SLP		(1U << 3)
+#define		QCOM_APCS_CPU_PWR_CTL_CLAMP		(1U << 0)
+
+#define	QCOM_APC_PWR_GATE_CTL				0x14
+#define		QCOM_APC_PWR_GATE_CTL_BHS_CNT_SHIFT	24
+#define		QCOM_APC_PWR_GATE_CTL_LDO_PWR_DWN_SHIFT	16
+#define		QCOM_APC_PWR_GATE_CTL_LDO_BYP_SHIFT	8
+#define		QCOM_APC_PWR_GATE_CTL_BHS_SEG_SHIFT	1
+#define		QCOM_APC_PWR_GATE_CTL_BHS_EN		(1U << 0)
+
+
+/*
+ * L2 cache regulator registers.
+ */
+#define	QCOM_APCS_SAW2_2_VCTL        0x1c
+
+#endif	/* __QCOM_CPU_KPSSV2_REG_H__ */
diff --git a/sys/arm/qualcomm/std.ipq4018 b/sys/arm/qualcomm/std.ipq4018
index 6492dbd06b1b..099fd81b5171 100644
--- a/sys/arm/qualcomm/std.ipq4018
+++ b/sys/arm/qualcomm/std.ipq4018
@@ -1,5 +1,6 @@
 arm/qualcomm/ipq4018_machdep.c		standard
 arm/qualcomm/ipq4018_mp.c		optional smp
 arm/qualcomm/qcom_scm_legacy.c		standard
+arm/qualcomm/qcom_cpu_kpssv2.c		optional smp
 
 dev/qcom_rnd/qcom_rnd.c			optional qcom_rnd



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