Thread (13 messages) 13 messages, 5 authors, 2017-11-17

[PATCH v7 1/3] arm: npcm: add basic support for Nuvoton BMCs

From: linux@armlinux.org.uk (Russell King - ARM Linux)
Date: 2017-10-20 10:48:33
Also in: linux-devicetree, lkml, openbmc 

On Thu, Oct 19, 2017 at 03:50:48PM -0700, Brendan Higgins wrote:
quoted hunk ↗ jump to hunk
Adds basic support for the Nuvoton NPCM750 BMC.

Signed-off-by: Brendan Higgins <redacted>
Reviewed-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Avi Fishman <avifishman70@gmail.com>
Tested-by: Tomer Maimon <tmaimon77@gmail.com>
Tested-by: Avi Fishman <avifishman70@gmail.com>
---
 arch/arm/Kconfig             |  2 +
 arch/arm/Makefile            |  1 +
 arch/arm/mach-npcm/Kconfig   | 48 ++++++++++++++++++++++++
 arch/arm/mach-npcm/Makefile  |  3 ++
 arch/arm/mach-npcm/headsmp.S | 17 +++++++++
 arch/arm/mach-npcm/npcm7xx.c | 34 +++++++++++++++++
 arch/arm/mach-npcm/platsmp.c | 88 ++++++++++++++++++++++++++++++++++++++++++++
 7 files changed, 193 insertions(+)
 create mode 100644 arch/arm/mach-npcm/Kconfig
 create mode 100644 arch/arm/mach-npcm/Makefile
 create mode 100644 arch/arm/mach-npcm/headsmp.S
 create mode 100644 arch/arm/mach-npcm/npcm7xx.c
 create mode 100644 arch/arm/mach-npcm/platsmp.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 61a0cb15067e..05543f1cfbde 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -782,6 +782,8 @@ source "arch/arm/mach-netx/Kconfig"
 
 source "arch/arm/mach-nomadik/Kconfig"
 
+source "arch/arm/mach-npcm/Kconfig"
+
 source "arch/arm/mach-nspire/Kconfig"
 
 source "arch/arm/plat-omap/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 47d3a1ab08d2..60ca50c7d762 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -191,6 +191,7 @@ machine-$(CONFIG_ARCH_MEDIATEK)		+= mediatek
 machine-$(CONFIG_ARCH_MXS)		+= mxs
 machine-$(CONFIG_ARCH_NETX)		+= netx
 machine-$(CONFIG_ARCH_NOMADIK)		+= nomadik
+machine-$(CONFIG_ARCH_NPCM)		+= npcm
 machine-$(CONFIG_ARCH_NSPIRE)		+= nspire
 machine-$(CONFIG_ARCH_OXNAS)		+= oxnas
 machine-$(CONFIG_ARCH_OMAP1)		+= omap1
diff --git a/arch/arm/mach-npcm/Kconfig b/arch/arm/mach-npcm/Kconfig
new file mode 100644
index 000000000000..21dfa8ce828f
--- /dev/null
+++ b/arch/arm/mach-npcm/Kconfig
@@ -0,0 +1,48 @@
+menuconfig ARCH_NPCM
+	bool "Nuvoton NPCM Architecture"
+	select ARCH_REQUIRE_GPIOLIB
+	select USE_OF
+	select PINCTRL
+	select PINCTRL_NPCM7XX
+
+if ARCH_NPCM
+
+comment "NPCMX50 CPU type"
+
+config CPU_NPCM750
+	depends on ARCH_NPCM && ARCH_MULTI_V7
+	bool "Support for NPCM750 BMC CPU (Poleg)"
+	select CACHE_L2X0
+	select CPU_V7
+	select ARM_GIC
+	select HAVE_SMP
+	select SMP
+	select SMP_ON_UP
+	select HAVE_ARM_SCU
+	select HAVE_ARM_TWD if SMP
+	select ARM_ERRATA_720789
+	select ARM_ERRATA_754322
+	select ARM_ERRATA_764369
+	select ARM_ERRATA_794072
+	select PL310_ERRATA_588369
+	select PL310_ERRATA_727915
+	select USB_EHCI_ROOT_HUB_TT
+	select USB_ARCH_HAS_HCD
+	select USB_ARCH_HAS_EHCI
+	select USB_EHCI_HCD
+	select USB_ARCH_HAS_OHCI
+	select USB_OHCI_HCD
+	select USB
+	select FIQ
+	select CPU_USE_DOMAINS
+	select GENERIC_CLOCKEVENTS
+	select CLKDEV_LOOKUP
+	select COMMON_CLK if OF
+	select NPCM750_TIMER
+	select MFD_SYSCON
+	help
+	  Support for NPCM750 BMC CPU (Poleg).
+
+	  Nuvoton NPCM750 BMC based on the Cortex A9.
+
+endif
diff --git a/arch/arm/mach-npcm/Makefile b/arch/arm/mach-npcm/Makefile
new file mode 100644
index 000000000000..78416055b854
--- /dev/null
+++ b/arch/arm/mach-npcm/Makefile
@@ -0,0 +1,3 @@
+AFLAGS_headsmp.o		+= -march=armv7-a
+
+obj-$(CONFIG_CPU_NPCM750)	+= npcm7xx.o platsmp.o headsmp.o
diff --git a/arch/arm/mach-npcm/headsmp.S b/arch/arm/mach-npcm/headsmp.S
new file mode 100644
index 000000000000..9fccbbd49ed4
--- /dev/null
+++ b/arch/arm/mach-npcm/headsmp.S
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2017 Google, Inc.
+ *
+ * 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(npcm7xx_secondary_startup)
+	safe_svcmode_maskall r0
+
+	b	secondary_startup
+ENDPROC(npcm7xx_secondary_startup)
Why do you need this?  The switch to svc mode is already handled by
secondary_startup.
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/mach-npcm/npcm7xx.c b/arch/arm/mach-npcm/npcm7xx.c
new file mode 100644
index 000000000000..132e9d587857
--- /dev/null
+++ b/arch/arm/mach-npcm/npcm7xx.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2017 Nuvoton Technology corporation.
+ * Copyright 2017 Google, Inc.
+ *
+ * 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/kernel.h>
+#include <linux/types.h>
+#include <asm/mach/arch.h>
+#include <asm/mach-types.h>
+#include <asm/mach/map.h>
+#include <asm/hardware/cache-l2x0.h>
+
+#define NPCM7XX_AUX_VAL (L310_AUX_CTRL_INSTR_PREFETCH |			       \
+			 L310_AUX_CTRL_DATA_PREFETCH |			       \
+			 L310_AUX_CTRL_NS_LOCKDOWN |			       \
+			 L310_AUX_CTRL_CACHE_REPLACE_RR |		       \
+			 L2C_AUX_CTRL_SHARED_OVERRIDE |			       \
+			 L310_AUX_CTRL_FULL_LINE_ZERO)
Do you really need all these flags?
quoted hunk ↗ jump to hunk
+
+static const char *const npcm7xx_dt_match[] = {
+	"nuvoton,npcm750",
+	NULL
+};
+
+DT_MACHINE_START(NPCM7XX_DT, "NPCMX50 Chip family")
+	.atag_offset	= 0x100,
+	.dt_compat	= npcm7xx_dt_match,
+	.l2c_aux_val	= NPCM7XX_AUX_VAL,
+	.l2c_aux_mask	= ~NPCM7XX_AUX_VAL,
+MACHINE_END
diff --git a/arch/arm/mach-npcm/platsmp.c b/arch/arm/mach-npcm/platsmp.c
new file mode 100644
index 000000000000..450e83c3c531
--- /dev/null
+++ b/arch/arm/mach-npcm/platsmp.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2017 Google, Inc.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "PLATSMP: " fmt
Maybe something more descriptive?

+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <asm/cacheflush.h>
+#include <asm/smp.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#define NPCM7XX_SCRPAD_REG 0x13c
+
+extern void npcm7xx_secondary_startup(void);
+
+static int npcm7xx_smp_boot_secondary(unsigned int cpu,
+				      struct task_struct *idle)
+{
+	struct device_node *gcr_np;
+	void __iomem *gcr_base;
+	int ret = 0;
+
+	gcr_np = of_find_compatible_node(NULL, NULL, "nuvoton,npcm750-gcr");
+	if (!gcr_np) {
+		pr_err("no gcr device node\n");
+		ret = -EFAULT;
EFAULT is used for bad userspace addresses, it should not be used for
other stuff - and a missing node is certainly not a "Bad address".

+		goto out;
+	}
+	gcr_base = of_iomap(gcr_np, 0);
+	if (!gcr_base) {
+		pr_err("could not iomap gcr at: 0x%p\n", gcr_base);
+		ret = -EFAULT;
This is more -ENOMEM.

+		goto out;
+	}
+
+	/* give boot ROM kernel start address. */
+	iowrite32(__pa_symbol(npcm7xx_secondary_startup), gcr_base +
+		  NPCM7XX_SCRPAD_REG);
+	/* make sure npcm7xx_secondary_startup is seen by all observers. */
+	smp_wmb();
I think you mean "make sure the previous write is seen by all observers".
However, doesn't "dsb_sev()" already do that?

+	dsb_sev();
+	/* make sure write buffer is drained */
+	mb();
This looks over the top. 

+
+	iounmap(gcr_base);
+out:
+	return ret;
+}
+
+static void __init npcm7xx_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *scu_np;
+	void __iomem *scu_base;
+
+	scu_np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+	if (!scu_np) {
+		pr_err("no scu device node\n");
+		return;
+	}
+	scu_base = of_iomap(scu_np, 0);
+	if (!scu_base) {
+		pr_err("could not iomap scu at: 0x%p\n", scu_base);
+		return;
+	}
+
+	scu_enable(scu_base);
+
+	iounmap(scu_base);
+}
+
+static struct smp_operations npcm7xx_smp_ops __initdata = {
+	.smp_prepare_cpus = npcm7xx_smp_prepare_cpus,
+	.smp_boot_secondary = npcm7xx_smp_boot_secondary,
+};
+
+CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm7xx-smp", &npcm7xx_smp_ops);
-- 
2.15.0.rc0.271.g36b669edcc-goog
-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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