[PATCH 0/7] ARM: BCM63xx: SMP support

[PATCH 0/7] ARM: BCM63xx: SMP support

[Florian Fainelli]

Hi all,

This patch series implements SMP support on the Broadcom BCM63138 DSL platform.

There is a number of decisions being made here to simplify things:

- the power on sequence for the secondary CPU is a bit of low-level code that
  uses the on-chip PMB bus, which will later be supported as a proper reset
  controller driver, it was considered first to use a reset controller for
  that, but this was later dropped because:
	- reset controllers cannot be utilized at SMP init time (too early)
	- moving reset controllers init earlier has been rejected
	- the second CPU power on sequence is fairly specific, even within
	  the context of the BCM63138 SoC, no other peripheral has that
	  level of detail

- VFP needs to be disabled when SMP is used because the second CPU does not
  have any VFP unit and will just hang doing a VFP/NEON operation

Florian Fainelli (7):
  Documentation: DT: Add Broadcom BCM63138 PMB binding
  ARM: dts: BCM63xx: Add PMB busses nodes
  Documentation: DT: Document SMP DT nodes and properties for BCM63138
  ARM: dts: BCM63xx: Add SMP nodes and required properties
  ARM: BCM63xx: Add Broadcom BCM63xx PMB controller helpers
  ARM: BCM63xx: Add secondary CPU PMB initialization sequence
  ARM: BCM63xx: Add SMP support for BCM63138

 .../devicetree/bindings/arm/bcm/bcm63138.txt       |  42 ++++
 .../bindings/reset/brcm,bcm63138-pmb.txt           |  19 ++
 arch/arm/boot/dts/bcm63138.dtsi                    |  20 ++
 arch/arm/mach-bcm/Makefile                         |   7 +-
 arch/arm/mach-bcm/bcm63xx_headsmp.S                |  23 +++
 arch/arm/mach-bcm/bcm63xx_pmb.c                    | 222 +++++++++++++++++++++
 arch/arm/mach-bcm/bcm63xx_smp.c                    | 171 ++++++++++++++++
 arch/arm/mach-bcm/bcm63xx_smp.h                    |   9 +
 include/linux/bcm63xx_pmb.h                        |  76 +++++++
 9 files changed, 588 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/reset/brcm,bcm63138-pmb.txt
 create mode 100644 arch/arm/mach-bcm/bcm63xx_headsmp.S
 create mode 100644 arch/arm/mach-bcm/bcm63xx_pmb.c
 create mode 100644 arch/arm/mach-bcm/bcm63xx_smp.c
 create mode 100644 arch/arm/mach-bcm/bcm63xx_smp.h
 create mode 100644 include/linux/bcm63xx_pmb.h

-- 
2.1.0

[PATCH 1/7] Documentation: DT: Add Broadcom BCM63138 PMB binding

[Florian Fainelli]

Add a Device Tree binding for the Broadcom BCM63138 Processor Monitor
Bus, which is an internal bus used to access different power and reset
signals within a BCM63138 System-on-a-Chip.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 .../devicetree/bindings/reset/brcm,bcm63138-pmb.txt   | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/brcm,bcm63138-pmb.txt

diff --git a/Documentation/devicetree/bindings/reset/brcm,bcm63138-pmb.txt b/Documentation/devicetree/bindings/reset/brcm,bcm63138-pmb.txt
new file mode 100644
index 000000000000..aa1eecd23046
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/brcm,bcm63138-pmb.txt
@@ -0,0 +1,19 @@
+Broadcom BCM63138 Processor Monitor Bus binding
+===============================================
+
+Please also refer to reset.txt in this directory for common reset
+controller binding usage.
+
+Require properties:
+
+- compatible: must be "brcm,bcm63138-pmb"
+- reg: base register address and size for this bus controller
+- #reset-cells: must be 2 first cell is the internal bus number, and the third
+  cell is the address on this bus
+
+Example:
+	pmb0: reset-controller at 4800c0 {
+		compatible = "brcm,bcm63138-pmb";
+		reg = <0x4800c0 0x10>;
+		#reset-cells = <2>;
+	};
-- 
2.1.0

[PATCH 1/7] Documentation: DT: Add Broadcom BCM63138 PMB binding

[Florian Fainelli]

2015-04-17 15:33 GMT-07:00 Florian Fainelli <f.fainelli@gmail.com>:
> Add a Device Tree binding for the Broadcom BCM63138 Processor Monitor
> Bus, which is an internal bus used to access different power and reset
> signals within a BCM63138 System-on-a-Chip.
>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> +- compatible: must be "brcm,bcm63138-pmb"
> +- reg: base register address and size for this bus controller
> +- #reset-cells: must be 2 first cell is the internal bus number, and the third
> +  cell is the address on this bus

I missed the fact that we need to represent the number of zones per
devices as a third cell here since some devices may have multiple
zones to be powered on. Will re-spin this series along with addressing
Russell's comments in patch 7.
--
Florian

[PATCH 2/7] ARM: dts: BCM63xx: Add PMB busses nodes

[Florian Fainelli]

Add the two BCM63138 PMB busses nodes found on this System-on-a-Chip as
described in their corresponding binding document.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/arm/boot/dts/bcm63138.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm/boot/dts/bcm63138.dtsi b/arch/arm/boot/dts/bcm63138.dtsi
index f46329c8ad75..f5b5c528c26c 100644
--- a/arch/arm/boot/dts/bcm63138.dtsi
+++ b/arch/arm/boot/dts/bcm63138.dtsi
@@ -105,6 +105,18 @@
 			reg = <0x1e620 0x20>;
 			interrupts = <GIC_PPI 14 IRQ_TYPE_LEVEL_HIGH>;
 		};
+
+		pmb0: reset-controller at 4800c0 {
+			compatible = "brcm,bcm63138-pmb";
+			reg = <0x4800c0 0x10>;
+			#reset-cells = <2>;
+		};
+
+		pmb1: reset-controller at 4800e0 {
+			compatible = "brcm,bcm63138-pmb";
+			reg = <0x4800e0 0x10>;
+			#reset-cells = <2>;
+		};
 	};
 
 	/* Legacy UBUS base */
-- 
2.1.0

[PATCH 3/7] Documentation: DT: Document SMP DT nodes and properties for BCM63138

[Florian Fainelli]

Add binding documentation for the additional nodes and properties
required to get the secondary CPU online on the BCM63138 SoC.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 .../devicetree/bindings/arm/bcm/bcm63138.txt       | 42 ++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/bcm/bcm63138.txt b/Documentation/devicetree/bindings/arm/bcm/bcm63138.txt
index bd49987a8812..18afe5b42549 100644
--- a/Documentation/devicetree/bindings/arm/bcm/bcm63138.txt
+++ b/Documentation/devicetree/bindings/arm/bcm/bcm63138.txt
@@ -7,3 +7,45 @@ following properties:
 Required root node property:
 
 compatible: should be "brcm,bcm63138"
+
+An optional Boot lookup table Device Tree node is required for secondary CPU
+initialization as well as a 'resets' phandle to the correct PMB controller as
+defined in reset/brcm,bcm63138-pmb.txt for this secondary CPU, and an
+'enable-method' property.
+
+Required properties for the Boot lookup table node:
+- compatible: should be "brcm,bcm63138-bootlut"
+- reg: register base address and length for the Boot Lookup table
+
+Optional properties for the primary CPU node:
+- enable-method: should be "brcm,bcm63138"
+
+Optional properties for the secondary CPU node:
+- enable-method: should be "brcm,bcm63138"
+- resets: phandle to the relevant PMB controller, one integer indicating the internal
+  bus number, and a second integer indicating the address of the CPU in the PMB
+  internal bus number.
+
+Example:
+
+	cpus {
+		cpu at 0 {
+			compatible = "arm,cotex-a9";
+			reg = <0>;
+			...
+			enable-method = "brcm,bcm63138";
+		};
+
+		cpu at 1 {
+			compatible = "arm,cortex-a9";
+			reg = <1>;
+			...
+			enable-method = "brcm,bcm63138";
+			resets = <&pmb0 0 4>;
+		};
+	};
+
+	bootlut: bootlut at 8000 {
+		compatible = "brcm,bcm63138-bootlut";
+		reg = <0x8000 0x50>;
+	};
-- 
2.1.0

[PATCH 4/7] ARM: dts: BCM63xx: Add SMP nodes and required properties

[Florian Fainelli]

Update bcm63138.dtsi with the following:

- enable-method for both CPU nodes
- brcm,bcm63138-bootlut node
- resets properties to point to the correct PMB controller to release
  the secondary CPU from reset

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/arm/boot/dts/bcm63138.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/bcm63138.dtsi b/arch/arm/boot/dts/bcm63138.dtsi
index f5b5c528c26c..cdbaa14c872c 100644
--- a/arch/arm/boot/dts/bcm63138.dtsi
+++ b/arch/arm/boot/dts/bcm63138.dtsi
@@ -26,6 +26,7 @@
 			compatible = "arm,cortex-a9";
 			next-level-cache = <&L2>;
 			reg = <0>;
+			enable-method = "brcm,bcm63138";
 		};
 
 		cpu at 1 {
@@ -33,6 +34,8 @@
 			compatible = "arm,cortex-a9";
 			next-level-cache = <&L2>;
 			reg = <1>;
+			enable-method = "brcm,bcm63138";
+			resets = <&pmb0 0 4>;
 		};
 	};
 
@@ -143,5 +146,10 @@
 			clock-names = "periph";
 			status = "disabled";
 		};
+
+		bootlut: bootlut at 8000 {
+			compatible = "brcm,bcm63138-bootlut";
+			reg = <0x8000 0x50>;
+		};
 	};
 };
-- 
2.1.0

[PATCH 5/7] ARM: BCM63xx: Add Broadcom BCM63xx PMB controller helpers

[Florian Fainelli]

This patch adds both common register definitions and helper functions
used to issue read/write commands to the Broadcom BCM63xx PMB controller
which is used to power on and release from reset internal on-chip
peripherals such as the integrated Ethernet switch, AHCI, USB, as well
as the secondary CPU core.

This is going to be utilized by the BCM63138 SMP code, as well as by the
BCM63138 reset controller later.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 include/linux/bcm63xx_pmb.h | 76 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 include/linux/bcm63xx_pmb.h

diff --git a/include/linux/bcm63xx_pmb.h b/include/linux/bcm63xx_pmb.h
new file mode 100644
index 000000000000..2a2ea1bfb6cf
--- /dev/null
+++ b/include/linux/bcm63xx_pmb.h
@@ -0,0 +1,76 @@
+#ifndef __BCM63XX_PMB_H
+#define __BCM63XX_PMB_H
+
+#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+
+/* PMB Master controller register */
+#define PMB_CTRL		0x00
+#define  PMC_PMBM_START		(1 << 31)
+#define  PMC_PMBM_TIMEOUT	(1 << 30)
+#define  PMC_PMBM_SLAVE_ERR	(1 << 29)
+#define  PMC_PMBM_BUSY		(1 << 28)
+#define  PMC_PMBM_READ		(0 << 20)
+#define  PMC_PMBM_WRITE		(1 << 20)
+#define PMB_WR_DATA		0x04
+#define PMB_TIMEOUT		0x08
+#define PMB_RD_DATA		0x0C
+
+#define PMB_BUS_ID_SHIFT	8
+
+/* Perform the low-level PMB master operation, shared between reads and
+ * writes, caller must hold the spinlock
+ */
+static inline int __bpcm_do_op(void __iomem *master, unsigned int addr,
+			       u32 off, u32 op)
+{
+	unsigned int timeout = 1000;
+	u32 cmd;
+
+	cmd = (PMC_PMBM_START | op | (addr & 0xff) << 12 | off);
+	__raw_writel(cmd, master + PMB_CTRL);
+	do {
+		cmd = __raw_readl(master + PMB_CTRL);
+		if (!(cmd & PMC_PMBM_START))
+			return 0;
+
+		if (cmd & PMC_PMBM_SLAVE_ERR)
+			return -EIO;
+
+		if (cmd & PMC_PMBM_TIMEOUT)
+			return -ETIMEDOUT;
+
+		udelay(1);
+	} while (timeout-- > 0);
+
+	return -ETIMEDOUT;
+}
+
+static inline int bpcm_rd(void __iomem *master, unsigned int addr,
+			  u32 off, u32 *val)
+{
+	int ret = 0;
+
+	ret = __bpcm_do_op(master, addr, off >> 2, PMC_PMBM_READ);
+	*val = __raw_readl(master + PMB_RD_DATA);
+
+	return ret;
+}
+
+static inline int bpcm_wr(void __iomem *master, unsigned int addr,
+			  u32 off, u32 val)
+{
+	int ret = 0;
+
+	__raw_writel(val, master + PMB_WR_DATA);
+	/* Ensure that writes to the PMB_WR_DATA registers are taken
+	 * into account before attempting to start the PMB transaction
+	 */
+	mb();
+	ret = __bpcm_do_op(master, addr, off >> 2, PMC_PMBM_WRITE);
+
+	return ret;
+}
+
+#endif /* __BCM63XX_PMB_H */
-- 
2.1.0

[PATCH 6/7] ARM: BCM63xx: Add secondary CPU PMB initialization sequence

[Florian Fainelli]

The sequence to initialize a secondary CPU using the BCM63138 PMB is
extremely specific and represents much more code than any other on-chip
peripheral (AHCI, USB 3.0 or integrated Ethernet switch), as such we
keep that code local and utilize Device Tree to lookup all the resources
we need from the CPU device tree node.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/arm/mach-bcm/bcm63xx_pmb.c | 222 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 222 insertions(+)
 create mode 100644 arch/arm/mach-bcm/bcm63xx_pmb.c

diff --git a/arch/arm/mach-bcm/bcm63xx_pmb.c b/arch/arm/mach-bcm/bcm63xx_pmb.c
new file mode 100644
index 000000000000..52521cddcd04
--- /dev/null
+++ b/arch/arm/mach-bcm/bcm63xx_pmb.c
@@ -0,0 +1,222 @@
+/*
+ * Broadcom BCM63138 PMB initialization for secondary CPU(s)
+ *
+ * Copyright (C) 2015 Broadcom Corporation
+ * Author: Florian Fainelli <f.fainelli@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/bcm63xx_pmb.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "bcm63xx_smp.h"
+
+/* ARM Control register definitions */
+#define CORE_PWR_CTRL_SHIFT	0
+#define CORE_PWR_CTRL_MASK	0x3
+#define PLL_PWR_ON		BIT(8)
+#define PLL_LDO_PWR_ON		BIT(9)
+#define PLL_CLAMP_ON		BIT(10)
+#define CPU_RESET_N(x)		BIT(13 + (x))
+#define NEON_RESET_N		BIT(15)
+#define PWR_CTRL_STATUS_SHIFT	28
+#define PWR_CTRL_STATUS_MASK	0x3
+#define PWR_DOWN_SHIFT		30
+#define PWR_DOWN_MASK		0x3
+
+/* CPU Power control register definitions */
+#define MEM_PWR_OK		BIT(0)
+#define MEM_PWR_ON		BIT(1)
+#define MEM_CLAMP_ON		BIT(2)
+#define MEM_PWR_OK_STATUS	BIT(4)
+#define MEM_PWR_ON_STATUS	BIT(5)
+#define MEM_PDA_SHIFT		8
+#define MEM_PDA_MASK		0xf
+#define  MEM_PDA_CPU_MASK	0x1
+#define  MEM_PDA_NEON_MASK	0xf
+#define CLAMP_ON		BIT(15)
+#define PWR_OK_SHIFT		16
+#define PWR_OK_MASK		0xf
+#define PWR_ON_SHIFT		20
+#define  PWR_CPU_MASK		0x03
+#define  PWR_NEON_MASK		0x01
+#define PWR_ON_MASK		0xf
+#define PWR_OK_STATUS_SHIFT	24
+#define PWR_OK_STATUS_MASK	0xf
+#define PWR_ON_STATUS_SHIFT	28
+#define PWR_ON_STATUS_MASK	0xf
+
+#define ARM_CONTROL		0x30
+#define ARM_PWR_CONTROL_BASE	0x34
+#define ARM_PWR_CONTROL(x)	(ARM_PWR_CONTROL_BASE + (x) * 0x4)
+#define ARM_NEON_L2		0x3c
+
+/* Perform a value write, then spin until the value shifted by
+ * shift is seen, masked with mask and is different from cond.
+ */
+static int bpcm_wr_rd_mask(void __iomem *master,
+			   unsigned int addr, u32 off, u32 *val,
+			   u32 shift, u32 mask, u32 cond)
+{
+	int ret;
+
+	ret = bpcm_wr(master, addr, off, *val);
+	if (ret)
+		return ret;
+
+	do {
+		ret = bpcm_rd(master, addr, off, val);
+		if (ret)
+			return ret;
+
+		cpu_relax();
+	} while (((*val >> shift) & mask) != cond);
+
+	return ret;
+}
+
+/* Global lock to serialize accesses to the PMB registers while we
+ * are bringing up the secondary CPU
+ */
+static DEFINE_SPINLOCK(pmb_lock);
+
+static int bcm63xx_pmb_get_resources(struct device_node *dn,
+				     void __iomem **base,
+				     unsigned int *cpu,
+				     unsigned int *bus,
+				     unsigned int *addr)
+{
+	struct device_node *pmb_dn;
+	struct of_phandle_args args;
+	int ret;
+
+	ret = of_property_read_u32(dn, "reg", cpu);
+	if (ret) {
+		pr_err("CPU is missing a reg node\n");
+		return ret;
+	}
+
+	ret = of_parse_phandle_with_args(dn, "resets", "#reset-cells",
+					 0, &args);
+	if (ret) {
+		pr_err("CPU is missing a resets phandle\n");
+		return ret;
+	}
+
+	pmb_dn = args.np;
+	if (args.args_count != 2) {
+		pr_err("reset-controller does not conform to reset-cells\n");
+		return -EINVAL;
+	}
+
+	*base = of_iomap(args.np, 0);
+	if (!*base) {
+		pr_err("failed remapping PMB register\n");
+		return -ENOMEM;
+	}
+
+	*bus = args.args[0];
+	*addr = args.args[1];
+
+	return 0;
+}
+
+int bcm63xx_pmb_power_on_cpu(struct device_node *dn)
+{
+	void __iomem *base;
+	unsigned int cpu, bus, addr;
+	unsigned long flags;
+	u32 val, ctrl;
+	int ret;
+
+	ret = bcm63xx_pmb_get_resources(dn, &base, &cpu, &bus, &addr);
+	if (ret)
+		return ret;
+
+	/* We would not know how to enable a third and greater CPU */
+	WARN_ON(cpu > 1);
+
+	spin_lock_irqsave(&pmb_lock, flags);
+
+	/* Check if the CPU is already on and save the ARM_CONTROL register
+	 * value since we will use it later for CPU de-assert once done with
+	 * the CPU-specific power sequence
+	 */
+	ret = bpcm_rd(base, addr, ARM_CONTROL, &ctrl);
+	if (ret)
+		return ret;
+
+	if (ctrl & CPU_RESET_N(cpu)) {
+		pr_info("PMB: CPU%d is already powered on\n", cpu);
+		ret = 0;
+		goto out;
+	}
+
+	/* Power on PLL */
+	ret = bpcm_rd(base, addr, ARM_PWR_CONTROL(cpu), &val);
+	if (ret)
+		goto out;
+
+	val |= (PWR_CPU_MASK << PWR_ON_SHIFT);
+
+	ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+			PWR_ON_STATUS_SHIFT, PWR_CPU_MASK, PWR_CPU_MASK);
+	if (ret)
+		goto out;
+
+	val |= (PWR_CPU_MASK << PWR_OK_SHIFT);
+
+	ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+			PWR_OK_STATUS_SHIFT, PWR_CPU_MASK, PWR_CPU_MASK);
+	if (ret)
+		goto out;
+
+	val &= ~CLAMP_ON;
+
+	ret = bpcm_wr(base, addr, ARM_PWR_CONTROL(cpu), val);
+	if (ret)
+		goto out;
+
+	/* Power on CPU<N> RAM */
+	val &= ~(MEM_PDA_MASK << MEM_PDA_SHIFT);
+
+	ret = bpcm_wr(base, addr, ARM_PWR_CONTROL(cpu), val);
+	if (ret)
+		goto out;
+
+	val |= MEM_PWR_ON;
+
+	ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+			0, MEM_PWR_ON_STATUS, MEM_PWR_ON_STATUS);
+	if (ret)
+		goto out;
+
+	val |= MEM_PWR_OK;
+
+	ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+			0, MEM_PWR_OK_STATUS, MEM_PWR_OK_STATUS);
+	if (ret)
+		goto out;
+
+	val &= ~MEM_CLAMP_ON;
+
+	ret = bpcm_wr(base, addr, ARM_PWR_CONTROL(cpu), val);
+	if (ret)
+		goto out;
+
+	/* De-assert CPU reset */
+	ctrl |= CPU_RESET_N(cpu);
+
+	ret = bpcm_wr(base, addr, ARM_CONTROL, ctrl);
+out:
+	spin_unlock_irqrestore(&pmb_lock, flags);
+	iounmap(base);
+	return ret;
+}
-- 
2.1.0

[PATCH 7/7] ARM: BCM63xx: Add SMP support for BCM63138

[Florian Fainelli]

Add support for booting the secondary CPU on BCM63138, this involves:

- locating the bootlut to write the reset vector
- powering up the second CPU when we need to using the DT-supplied PMB
  references
- disabling VFP when enabled such that we can keep having SMP

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/arm/mach-bcm/Makefile          |   7 +-
 arch/arm/mach-bcm/bcm63xx_headsmp.S |  23 +++++
 arch/arm/mach-bcm/bcm63xx_smp.c     | 171 ++++++++++++++++++++++++++++++++++++
 arch/arm/mach-bcm/bcm63xx_smp.h     |   9 ++
 4 files changed, 209 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-bcm/bcm63xx_headsmp.S
 create mode 100644 arch/arm/mach-bcm/bcm63xx_smp.c
 create mode 100644 arch/arm/mach-bcm/bcm63xx_smp.h

diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile
index 4c38674c73ec..647f43f0bace 100644
--- a/arch/arm/mach-bcm/Makefile
+++ b/arch/arm/mach-bcm/Makefile
@@ -38,7 +38,12 @@ obj-$(CONFIG_ARCH_BCM2835)	+= board_bcm2835.o
 obj-$(CONFIG_ARCH_BCM_5301X)	+= bcm_5301x.o
 
 # BCM63XXx
-obj-$(CONFIG_ARCH_BCM_63XX)	:= bcm63xx.o
+ifeq ($(CONFIG_ARCH_BCM_63XX),y)
+obj-y				+= bcm63xx.o
+CFLAGS_bcm63xx_headsmp.o	+= -march=armv7-a
+obj-$(CONFIG_SMP)		+= bcm63xx_smp.o bcm63xx_headsmp.o \
+				   bcm63xx_pmb.o
+endif
 
 ifeq ($(CONFIG_ARCH_BRCMSTB),y)
 CFLAGS_platsmp-brcmstb.o	+= -march=armv7-a
diff --git a/arch/arm/mach-bcm/bcm63xx_headsmp.S b/arch/arm/mach-bcm/bcm63xx_headsmp.S
new file mode 100644
index 000000000000..c7af397c7f14
--- /dev/null
+++ b/arch/arm/mach-bcm/bcm63xx_headsmp.S
@@ -0,0 +1,23 @@
+/*
+ *  Copyright (C) 2015, Broadcom Corporation
+ *  All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+
+ENTRY(bcm63138_secondary_startup)
+ ARM_BE8(setend	be)
+	/*
+	 * L1 cache does have unpredictable contents at power-up clean its
+	 * contents without flushing
+	 */
+	bl      v7_invalidate_l1
+	nop
+
+	b	secondary_startup
+ENDPROC(bcm63138_secondary_startup)
diff --git a/arch/arm/mach-bcm/bcm63xx_smp.c b/arch/arm/mach-bcm/bcm63xx_smp.c
new file mode 100644
index 000000000000..44fe96eda2b0
--- /dev/null
+++ b/arch/arm/mach-bcm/bcm63xx_smp.c
@@ -0,0 +1,171 @@
+/*
+ * Broadcom BCM63138 DSL SoCs SMP support code
+ *
+ * Copyright (C) 2015, Broadcom Corporation
+ *
+ * Licensed under the terms of the GPLv2
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/bcm63xx_pmb.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_scu.h>
+#include <asm/smp_plat.h>
+
+#include "bcm63xx_smp.h"
+
+/* Size of mapped Cortex A9 SCU address space */
+#define CORTEX_A9_SCU_SIZE	0x58
+
+extern unsigned int VFP_arch;
+
+/*
+ * Enable the Cortex A9 Snoop Control Unit
+ *
+ * By the time this is called we already know there are multiple
+ * cores present.  We assume we're running on a Cortex A9 processor,
+ * so any trouble getting the base address register or getting the
+ * SCU base is a problem.
+ *
+ * Return 0 if successful or an error code otherwise.
+ */
+static int __init scu_a9_enable(void)
+{
+	unsigned long config_base;
+	void __iomem *scu_base;
+	unsigned int i, ncores;
+
+	if (!scu_a9_has_base()) {
+		pr_err("no configuration base address register!\n");
+		return -ENXIO;
+	}
+
+	/* Config base address register value is zero for uniprocessor */
+	config_base = scu_a9_get_base();
+	if (!config_base) {
+		pr_err("hardware reports only one core\n");
+		return -ENOENT;
+	}
+
+	scu_base = ioremap((phys_addr_t)config_base, CORTEX_A9_SCU_SIZE);
+	if (!scu_base) {
+		pr_err("failed to remap config base (%lu/%u) for SCU\n",
+			config_base, CORTEX_A9_SCU_SIZE);
+		return -ENOMEM;
+	}
+
+	scu_enable(scu_base);
+
+	ncores = scu_base ? scu_get_core_count(scu_base) : 1;
+
+	if (ncores > nr_cpu_ids) {
+		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
+				ncores, nr_cpu_ids);
+		ncores = nr_cpu_ids;
+	}
+
+	/* The BCM63138 SoC has two Cortex-A9 CPUs, CPU0 features a complete
+	 * and fully functional VFP unit that can be used, but CPU1 does not.
+	 * Since we will not be able to trap kernel-mode NEON to force
+	 * migration to CPU0, just do not advertise VFP support at all.
+	 *
+	 * This will make vfp_init bail out and do not attempt to use VFP at
+	 * all, for kernel-mode NEON, we do not want to introduce any
+	 * conditionals in hot-paths, so we just restrict the system to UP.
+	 */
+#ifdef CONFIG_VFP
+	if (ncores > 1) {
+		pr_warn("SMP: secondary CPUs lack VFP unit, disabling VFP\n");
+		VFP_arch = 1;
+
+#ifdef CONFIG_KERNEL_MODE_NEON
+		WARN(1, "SMP: kernel-mode NEON enabled, restricting to UP\n");
+		ncores = 1;
+#endif
+	}
+#endif
+
+	for (i = 0; i < ncores; i++)
+		set_cpu_possible(i, true);
+
+	iounmap(scu_base);	/* That's the last we'll need of this */
+
+	return 0;
+}
+
+static const struct of_device_id bcm63138_bootlut_ids[] = {
+	{ .compatible = "brcm,bcm63138-bootlut", },
+	{ /* sentinel */ },
+};
+
+#define BOOTLUT_RESET_VECT	0x20
+
+static int bcm63138_smp_boot_secondary(unsigned int cpu,
+				       struct task_struct *idle)
+{
+	void __iomem *bootlut_base;
+	struct device_node *dn;
+	int ret = 0;
+	u32 val;
+
+	dn = of_find_matching_node(NULL, bcm63138_bootlut_ids);
+	if (!dn) {
+		pr_err("SMP: unable to find bcm63138 boot LUT node\n");
+		return -ENODEV;
+	}
+
+	bootlut_base = of_iomap(dn, 0);
+	of_node_put(dn);
+
+	if (!bootlut_base) {
+		pr_err("SMP: unable to remap boot LUT base register\n");
+		return -ENOMEM;
+	}
+
+	/* Locate the secondary CPU node */
+	dn = of_get_cpu_node(cpu_logical_map(cpu), NULL);
+	if (!dn) {
+		pr_err("SMP: failed to locate secondary CPU%d node\n", cpu);
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/* Write the secondary init routine to the BootLUT reset vector */
+	val = virt_to_phys(bcm63138_secondary_startup);
+	writel_relaxed(val, bootlut_base + BOOTLUT_RESET_VECT);
+
+	/* Power up the core, will jump straight to its reset vector when we
+	 * return
+	 */
+	ret = bcm63xx_pmb_power_on_cpu(dn);
+	if (ret)
+		goto out;
+out:
+	iounmap(bootlut_base);
+
+	return ret;
+}
+
+static void __init bcm63138_smp_prepare_cpus(unsigned int max_cpus)
+{
+	int ret;
+
+	ret = scu_a9_enable();
+	if (ret) {
+		pr_warn("SMP: Cortex-A9 SCU setup failed\n");
+		return;
+	}
+}
+
+struct smp_operations bcm63138_smp_ops __initdata = {
+	.smp_prepare_cpus	= bcm63138_smp_prepare_cpus,
+	.smp_boot_secondary	= bcm63138_smp_boot_secondary,
+};
+
+CPU_METHOD_OF_DECLARE(bcm63138_smp, "brcm,bcm63138", &bcm63138_smp_ops);
diff --git a/arch/arm/mach-bcm/bcm63xx_smp.h b/arch/arm/mach-bcm/bcm63xx_smp.h
new file mode 100644
index 000000000000..50b76044536e
--- /dev/null
+++ b/arch/arm/mach-bcm/bcm63xx_smp.h
@@ -0,0 +1,9 @@
+#ifndef __BCM63XX_SMP_H
+#define __BCM63XX_SMP_H
+
+struct device_node;
+
+extern void bcm63138_secondary_startup(void);
+extern int bcm63xx_pmb_power_on_cpu(struct device_node *dn);
+
+#endif /* __BCM63XX_SMP_H */
-- 
2.1.0

[PATCH 7/7] ARM: BCM63xx: Add SMP support for BCM63138

[Russell King - ARM Linux]

On Fri, Apr 17, 2015 at 03:33:52PM -0700, Florian Fainelli wrote:
> +
> +extern unsigned int VFP_arch;
...
> +	/* The BCM63138 SoC has two Cortex-A9 CPUs, CPU0 features a complete
> +	 * and fully functional VFP unit that can be used, but CPU1 does not.
> +	 * Since we will not be able to trap kernel-mode NEON to force
> +	 * migration to CPU0, just do not advertise VFP support at all.
> +	 *
> +	 * This will make vfp_init bail out and do not attempt to use VFP at
> +	 * all, for kernel-mode NEON, we do not want to introduce any
> +	 * conditionals in hot-paths, so we just restrict the system to UP.
> +	 */
> +#ifdef CONFIG_VFP
> +	if (ncores > 1) {
> +		pr_warn("SMP: secondary CPUs lack VFP unit, disabling VFP\n");
> +		VFP_arch = 1;

What makes you think that doing this hack would be somehow acceptable?

Please, do the job properly.  Add a function hook into the VFP code
called "vfp_disable()" so that it's obvious that you want to disable
it - and, because that code will be localised to VFP, it then becomes
acceptable to set VFP_arch=1.  Don't rely on current VFP behaviour
through setting VFP_arch directly in from platform code - that's
nothing more than a hack and a disgusting layering violation.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.