2017-11-06 10:37:04

by Tomer Maimon

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

On 4 November 2017 at 02:49, Brendan Higgins <[email protected]> wrote:
> On Thu, Oct 26, 2017 at 4:45 AM, Tomer Maimon <[email protected]> wrote:
>> Hi Brendan,
>>
>> Sorry for the delay,
>>
>> On 21 October 2017 at 00:08, Russell King - ARM Linux
>> <[email protected]> wrote:
>>> On Fri, Oct 20, 2017 at 01:57:47PM -0700, Brendan Higgins wrote:
>>>> On Fri, Oct 20, 2017 at 3:48 AM, Russell King - ARM Linux
>>>> <[email protected]> wrote:
>>>> > On Thu, Oct 19, 2017 at 03:50:48PM -0700, Brendan Higgins wrote:
>>>> >> Adds basic support for the Nuvoton NPCM750 BMC.
>>>> >>
>>>> >> Signed-off-by: Brendan Higgins <[email protected]>
>>>> >> Reviewed-by: Tomer Maimon <[email protected]>
>>>> >> Reviewed-by: Avi Fishman <[email protected]>
>>>> >> Tested-by: Tomer Maimon <[email protected]>
>>>> >> Tested-by: Avi Fishman <[email protected]>
>>>> >> ---
>>>> >> 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
>>
>> I started the upstream process of NPCM7xx clocksource driver, I got
>> the following comment
>> https://www.spinics.net/lists/devicetree/msg197916.html
>>
>> Is it possible to modify the the architecture configuration name to
>> ARCH_NPCM7XX.
>
> You mean the CPU config: CPU_NPCM7XX?
Sorry about the confusion, I mean to modify the CPU_NPCM750 to ARCH_NPCM750.
>
> I think the ARCH_NPCM is right, since that corresponds to this directory
> which is for all ARM Nuvoton BMCs.
>
>>
>>>> >> + 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.
>>>>
>>>> Florian Fainelli already brought this up:
>>>> https://www.spinics.net/lists/arm-kernel/msg605126.html
>>>> Without this the kernel complains that the core is started in
>>>> "wrong/inconsistent mode":
>>>
>>> The solution would be a comment to indicate why it's necessary :)
>>>
>>>>
>>>> SMP: Total of 2 processors activated (398.13 BogoMIPS).
>>>> CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU
>>>> mode 0x13)
>>>> CPU: This may indicate a broken bootloader or firmware.
>>>>
>>>> >
>>>> >> 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?
>>>>
>>>> Tomer, Avi, do we need these? I got this from the original version of
>>>> the driver.
>>>
>>> The l2c driver manages L310_AUX_CTRL_FULL_LINE_ZERO itself, so you
>>> shouldn't specify that.
>>>
>>> L2C_AUX_CTRL_SHARED_OVERRIDE is managed via the "arm,shared-override"
>>> DT property, so you should use that in DT instead.
>>>
>>> Prefetching needs the prefetch control register configured to tune the
>>> prefetching - that's platform specific so the l2c driver doesn't touch
>>> it (it expects firmware to have configured it.) If firmware needs to
>>> configure that, it might as well configure the flags too as they're
>>> shared into that very same register. If not, I think the l2c prefetch
>>> register defaults to a very small prefetch, and is probably not worth
>>> setting the enable bits without configuring the depth of prefetch.
>>
>> Yes, we do it in the firmware.
>>
>>>
>>> L310_AUX_CTRL_NS_LOCKDOWN is always enabled by the l2c driver, so
>>> shouldn't be necessary.
>>>
>>> So that leaves only L310_AUX_CTRL_CACHE_REPLACE_RR.
>>>
>>
>> You dont need to add L310_AUX_CTRL_CACHE_REPLACE_RR to the l2c aux value.
>>
>>>>
>>>> >
>>>> >> +
>>>> >> +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/
>>>> > FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
>>>> > According to speedtest.net: 8.21Mbps down 510kbps up
>>>
>>> --
>>> RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
>>> FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
>>> According to speedtest.net: 8.21Mbps down 510kbps up
>>
>> Thanks,
>>
>> Tomer

Thanks

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