Re: [PATCH v2 1/3] arm: npcm: add basic support for Nuvoton BMCs

From: Tomer Maimon
Date: Mon Sep 04 2017 - 10:24:13 EST

On 1 September 2017 at 01:53, Brendan Higgins <brendanhiggins@xxxxxxxxxx> wrote:
> Adds basic support for the Nuvoton NPCM750 BMC.
>
> Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> ---
> arch/arm/Kconfig | 2 +
> arch/arm/Makefile | 1 +
> arch/arm/mach-npcm/Kconfig | 58 +++++++++++++++
> arch/arm/mach-npcm/Makefile | 3 +
> arch/arm/mach-npcm/headsmp.S | 120 +++++++++++++++++++++++++++++++
> arch/arm/mach-npcm/npcm7xx.c | 34 +++++++++
> arch/arm/mach-npcm/platsmp.c | 168 +++++++++++++++++++++++++++++++++++++++++++
> 7 files changed, 386 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..a45670e516b4
> --- /dev/null
> +++ b/arch/arm/mach-npcm/Kconfig
> @@ -0,0 +1,58 @@
> +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 && !CPU_V6 && !CPU_V6K
> + bool "Support for NPCM750 BMC CPU (Poleg)"
> + select CACHE_L2X0
> + select CPU_V7
> + select ARM_GIC
> + select ARM_ERRATA_754322
> + select ARM_ERRATA_764369
> + 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 COMMON_CLK if OF
> + select NPCM750_TIMER
> + select MFD_SYSCON
> + help
> + Support for single core NPCM750 BMC CPU (Poleg).
> +
> + Single core variant of the Nuvoton NPCM750 BMC based on the Cortex A9.
> +
> +config CPU_NPCM750_SMP
> + depends on CPU_NPCM750
> + bool "Support for NPCM750 BMC CPU SMP (Poleg)"
> + select HAVE_SMP
> + select HAVE_ARM_SCU
> + select ARM_ERRATA_794072
> + select PL310_ERRATA_588369
> + select PL310_ERRATA_727915
> + select ARM_ERRATA_720789
> + select DEBUG_SPINLOCK
> + select GENERIC_CLOCKEVENTS
> + select SMP
> + select HAVE_ARM_TWD if SMP
> + select HAVE_ARM_SCU if SMP
> + select CLKDEV_LOOKUP
> + select COMMON_CLK if OF
> + help
> + Support for dual core NPCM750 BMC CPU (Poleg).
> +
> + Dual core variant of the 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..634e7c4d6b98
> --- /dev/null
> +++ b/arch/arm/mach-npcm/Makefile
> @@ -0,0 +1,3 @@
> +obj-$(CONFIG_CPU_NPCM750_SMP) += platsmp.o headsmp.o
> +
> +obj-$(CONFIG_CPU_NPCM750) += npcm7xx.o
> diff --git a/arch/arm/mach-npcm/headsmp.S b/arch/arm/mach-npcm/headsmp.S
> new file mode 100644
> index 000000000000..d22d2fc1a35c
> --- /dev/null
> +++ b/arch/arm/mach-npcm/headsmp.S
> @@ -0,0 +1,120 @@
> +/*
> + * linux/arch/arm/mach-realview/headsmp.S
> + *
> + * Copyright (c) 2003 ARM Limited
> + * Copyright 2017 Google, Inc.
> + * 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>
> +
> +.equ SVC_MODE, 0x13
> +.equ I_BIT, 0x80
> +.equ F_BIT, 0x40
> +
> +ENTRY(npcm7xx_wakeup_z1)
> + stmfd sp!, {r0-r12, lr}
> + ldr r0, =0x01
> + ldr r1, =0x01
> + ldr r2, =0x01
> +
> + and r3, r0, #0x0F /* Mask off unused bits of ID, and move to r3 */
> + and r1, r1, #0x0F /* Mask off unused bits of target_filter */
> + and r2, r2, #0x0F /* Mask off unused bits of filter_list */
> +
> + orr r3, r3, r1, LSL #16 /* Combine ID and target_filter */
> + orr r3, r3, r2, LSL #24 /* and now the filter list */
> +
> + /* Get the address of the GIC */
> + mrc p15, 4, r0, c15, c0, 0 /* Read periph base address */
> + add r0, r0, #0x1F00 /* Add offset of the sgi_trigger reg */
> +
> + /* Write to the Software Generated Interrupt Register (ICDSGIR) */
> + str r3, [r0]
> +
> + ldmfd sp!, {r0-r12, pc}
> +ENDPROC(npcm7xx_wakeup_z1)
> +
> +ENTRY(v7_invalidate_l1_npcmX50)
> + mov r0, #0
> + mcr p15, 0, r0, c7, c5, 0 /* invalidate I cache */
> + mcr p15, 2, r0, c0, c0, 0
> + mrc p15, 1, r0, c0, c0, 0
> +
> + ldr r1, =0x7fff
> + and r2, r1, r0, lsr #13
> +
> + ldr r1, =0x3ff
> +
> + and r3, r1, r0, lsr #3 /* NumWays - 1 */
> + add r2, r2, #1 /* NumSets */
> +
> + and r0, r0, #0x7
> + add r0, r0, #4 /* SetShift */
> +
> + clz r1, r3 /* WayShift */
> + add r4, r3, #1 /* NumWays */
> +1: sub r2, r2, #1 /* NumSets-- */
> + mov r3, r4 /* Temp = NumWays */
> +2: subs r3, r3, #1 /* Temp-- */
> + mov r5, r3, lsl r1
> + mov r6, r2, lsl r0
> + /* Reg = (Temp << WayShift) | (NumSets << SetShift) */
> + orr r5, r5, r6
> + mcr p15, 0, r5, c7, c6, 2
> + bgt 2b
> + cmp r2, #0
> + bgt 1b
> + dsb
> + isb
> + mov pc, lr
> +ENDPROC(v7_invalidate_l1_npcmX50)
> +
> +/*
> + * MSM specific entry point for secondary CPUs. This provides
> + * a "holding pen" into which all secondary cores are held until we're
> + * ready for them to initialise.
> + */
> +ENTRY(npcm7xx_secondary_startup)
> + msr CPSR_c, #(SVC_MODE)
> +
> + bl v7_invalidate_l1_npcmX50
> + /* disable vector table remapping */
> + mrc p15, 0,r0, c1, c0, 0
> + and r0, #0xffffdfff
> + mcr p15, 0,r0, c1, c0, 0
> +
> +#ifdef CONFIG_CACHE_L2X0
> + /* Enable L1 & L2 prefetch + Zero line */
> + mrc p15, 0, r0, c1, c0, 1
> + orr r0, r0, #(7 << 1)
> + mcr p15, 0, r0, c1, c0, 1
> +#endif /* CONFIG_CACHE_L2X0 */
> +
> + mrc p15, 0, r0, c0, c0, 5
> + and r0, r0, #15
> + adr r4, 1f
> + ldmia r4, {r5, r6}
> + sub r4, r4, r5
> + add r6, r6, r4
> + str r3,[r2]
> +
> +pen: ldr r7, [r6]
> + cmp r7, r0
> + bne pen
> +
> + /*
> + * we've been released from the holding pen: secondary_stack
> + * should now contain the SVC stack for this core
> + */
> + b secondary_startup
> +ENDPROC(npcm7xx_secondary_startup)
> +
> + .align
> +1: .long .
> + .long pen_release
> diff --git a/arch/arm/mach-npcm/npcm7xx.c b/arch/arm/mach-npcm/npcm7xx.c
> new file mode 100644
> index 000000000000..106dc62dd62b
> --- /dev/null
> +++ b/arch/arm/mach-npcm/npcm7xx.c
> @@ -0,0 +1,34 @@
> +/*
> + * Copyright (c) 2014 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 as published by
> + * the Free Software Foundation;version 2 of the License.
> + */
> +
> +#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)
> +
> +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..4b53adb467fc
> --- /dev/null
> +++ b/arch/arm/mach-npcm/platsmp.c
> @@ -0,0 +1,168 @@
> +/*
> + * Copyright (C) 2002 ARM Ltd.
> + * Copyright (C) 2008 STMicroelctronics.
> + * Copyright (C) 2009 ST-Ericsson.
> + * Copyright 2017 Google, Inc.
> + *
> + * This file is based on arm realview platform
> + *
> + * 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
> +
> +#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
> +
> +static void __iomem *gcr_base;
> +static void __iomem *scu_base;
> +
> +/* This is called from headsmp.S to wakeup the secondary core */
> +extern void npcm7xx_secondary_startup(void);
> +extern void npcm7xx_wakeup_z1(void);
> +
> +/*
> + * Write pen_release in a way that is guaranteed to be visible to all
> + * observers, irrespective of whether they're taking part in coherency
> + * or not. This is necessary for the hotplug code to work reliably.
> + */
> +static void npcm7xx_write_pen_release(int val)
> +{
> + pen_release = val;
> + /* write to pen_release must be visible to all observers. */
> + smp_wmb();
> + __cpuc_flush_dcache_area((void *) &pen_release, sizeof(pen_release));
> + outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
> +}
> +
> +static DEFINE_SPINLOCK(boot_lock);
> +
> +static void npcm7xx_smp_secondary_init(unsigned int cpu)
> +{
> + /*
> + * let the primary processor know we're out of the
> + * pen, then head off into the C entry point
> + */
> + npcm7xx_write_pen_release(-1);
> +
> + /*
> + * Synchronise with the boot thread.
> + */
> + spin_lock(&boot_lock);
> + spin_unlock(&boot_lock);
> +}
> +
> +static int npcm7xx_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
> +{
> + unsigned long timeout;
> +
> + if (!gcr_base)
> + return -EIO;
> +
> + /*
> + * set synchronisation state between this boot processor
> + * and the secondary one
> + */
> + spin_lock(&boot_lock);
> +
> + /*
> + * The secondary processor is waiting to be released from
> + * the holding pen - release it, then wait for it to flag
> + * that it has been released by resetting pen_release.
> + */
> + npcm7xx_write_pen_release(cpu_logical_map(cpu));
> + iowrite32(virt_to_phys(npcm7xx_secondary_startup),
> + gcr_base + NPCM7XX_SCRPAD_REG);
> + /* make npcm7xx_secondary_startup visible to all observers. */
> + smp_rmb();
> +
> + arch_send_wakeup_ipi_mask(cpumask_of(cpu));
> + timeout = jiffies + (HZ * 1);
> + while (time_before(jiffies, timeout)) {
> + /* make sure we see any writes to pen_release. */
> + smp_rmb();
> + if (pen_release == -1)
> + break;
> +
> + udelay(10);
> + }
> +
> + /*
> + * now the secondary core is starting up let it run its
> + * calibrations, then wait for it to finish
> + */
> + spin_unlock(&boot_lock);
> +
> + return pen_release != -1 ? -EIO : 0;
> +}
> +
> +
> +static void __init npcm7xx_wakeup_secondary(void)
> +{
> + /*
> + * write the address of secondary startup into the backup ram register
> + * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
> + * backup ram register at offset 0x1FF0, which is what boot rom code
> + * is waiting for. This would wake up the secondary core from WFE
> + */
> + iowrite32(virt_to_phys(npcm7xx_secondary_startup), gcr_base +
> + NPCM7XX_SCRPAD_REG);
> + /* make sure npcm7xx_secondary_startup is seen by all observers. */
> + smp_wmb();
> + dsb_sev();
> +
> + /* make sure write buffer is drained */
> + mb();
> +}
> +
> +static void __init npcm7xx_smp_prepare_cpus(unsigned int max_cpus)
> +{
> + struct device_node *gcr_np, *scu_np;
> +
> + gcr_np = of_find_compatible_node(NULL, NULL, "nuvoton,npcm750-gcr");
> + if (!gcr_np) {
> + pr_err("no gcr device node\n");
> + return;
> + }
> + gcr_base = of_iomap(gcr_np, 0);
> + if (!gcr_base) {
> + pr_err("could not iomap gcr at: 0x%llx\n", gcr_base);
> + return;
> + }
> +
> + 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 gcr at: 0x%llx\n", scu_base);
> + return;
> + }
> +
> + scu_enable(scu_base);
> + npcm7xx_wakeup_secondary();
> +}
> +
> +static struct smp_operations npcm7xx_smp_ops __initdata = {
> + .smp_prepare_cpus = npcm7xx_smp_prepare_cpus,
> + .smp_boot_secondary = npcm7xx_smp_boot_secondary,
> + .smp_secondary_init = npcm7xx_smp_secondary_init,
> +};
> +
> +CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm7xx-smp", &npcm7xx_smp_ops);
> --
> 2.14.1.581.gf28d330327-goog
>

Reviewed-by: Tomer Maimon <tmaimon77@xxxxxxxxx>
Tested-by: Tomer Maimon <tmaimon77@xxxxxxxxx>

Reviewed-by: Avi Fishman <avifishman70@xxxxxxxxx>
Tested-by: Avi Fishman <avifishman70@xxxxxxxxx>