[U-Boot] [PATCH v3] mx6: add support of multi-processor command

Stefano Babic
2014-06-24T12:50:31Z

Hi Gabriel,

On 22/06/2014 18:56, Gabriel Huau wrote:
> This allows u-boot to load different OS or Bare Metal application on the
> different cores of the i.MX6DQ.
> For example: we can run Android on cpu0 and a RT OS like QNX/FreeRTOS on cpu1.
>
> Signed-off-by: Gabriel Huau <contact@huau-gabriel.fr>
> ---
> Changes for v2:
> - Add a commit log message to explain the purpose of this patch
> Changes for v3:
> - Remove unnecessary check for unsigned values when they are negative
>
> arch/arm/cpu/armv7/mx6/Makefile | 1 +
> arch/arm/cpu/armv7/mx6/mp.c | 131 +++++++++++++++++++++++++++++++
> arch/arm/include/asm/arch-mx6/imx-regs.h | 13 +++
> 3 files changed, 145 insertions(+)
> create mode 100644 arch/arm/cpu/armv7/mx6/mp.c
>
> diff --git a/arch/arm/cpu/armv7/mx6/Makefile b/arch/arm/cpu/armv7/mx6/Makefile
> index d7285fc..ec08526 100644
> --- a/arch/arm/cpu/armv7/mx6/Makefile
> +++ b/arch/arm/cpu/armv7/mx6/Makefile
> @@ -9,3 +9,4 @@
>
> obj-y := soc.o clock.o
> obj-$(CONFIG_SECURE_BOOT) += hab.o
> +obj-$(CONFIG_MP) += mp.o
> diff --git a/arch/arm/cpu/armv7/mx6/mp.c b/arch/arm/cpu/armv7/mx6/mp.c

Do you have a user of this code ? I do not see it at the mopment.

> new file mode 100644
> index 0000000..8105fcc
> --- /dev/null
> +++ b/arch/arm/cpu/armv7/mx6/mp.c
> @@ -0,0 +1,131 @@
> +/*
> + * (C) Copyright 2014
> + * Gabriel Huau <contact@huau-gabriel.fr>
> + *
> + * (C) Copyright 2009 Freescale Semiconductor, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <asm/io.h>
> +#include <asm/errno.h>
> +#include <asm/arch/imx-regs.h>
> +
> +int cpu_reset(int nr)
> +{

As cpu__ are quite too generic and could conflict, I suggest to use more
specific names indicating that you are enabling/disabling a core on the
cpu. Something like imx_core_reset() or whatever you choose.

> + uint32_t reg;
> + struct src *src = (struct src *)SRC_BASE_ADDR;
> +
> + reg = __raw_readl(&src->scr);
> +
> + switch (nr) {
> + case 1:
> + reg |= SRC_SCR_CORE_1_RESET_MASK;
> + break;
> +
> + case 2:
> + reg |= SRC_SCR_CORE_2_RESET_MASK;
> + break;
> +
> + case 3:
> + reg |= SRC_SCR_CORE_3_RESET_MASK;
> + break;
> + }
> +
> + /* Software reset of the CPU N */
> + __raw_writel(reg, &src->scr);
> +
> + return 0;
> +}
> +
> +int cpu_status(int nr)
> +{
> + uint32_t reg;
> + struct src *src = (struct src *)SRC_BASE_ADDR;
> +
> + reg = __raw_readl(&src->scr);
> +
> + switch (nr) {
> + case 1:
> + printf("core 1: %d\n", !!(reg & SRC_SCR_CORE_1_ENABLE_MASK));
> + break;
> +
> + case 2:
> + printf("core 2: %d\n", !!(reg & SRC_SCR_CORE_2_ENABLE_MASK));
> + break;
> +
> + case 3:
> + printf("core 3: %d\n", !!(reg & SRC_SCR_CORE_3_ENABLE_MASK));
> + break;
> + }
> +
> + return 0;
> +}
> +
> +int cpu_release(int nr, int argc, char *const argv[])
> +{
> + uint32_t reg;
> + struct src *src = (struct src *)SRC_BASE_ADDR;
> + uint32_t boot_addr;
> +
> + boot_addr = simple_strtoul(argv[0], NULL, 16);
> + reg = __raw_readl(&src->scr);
> +
> + switch (nr) {
> + case 1:
> + __raw_writel(boot_addr, &src->gpr3);
> + reg |= SRC_SCR_CORE_1_ENABLE_MASK;
> + break;
> +
> + case 2:
> + __raw_writel(boot_addr, &src->gpr5);
> + reg |= SRC_SCR_CORE_2_ENABLE_MASK;
> + break;
> +
> + case 3:
> + __raw_writel(boot_addr, &src->gpr7);
> + reg |= SRC_SCR_CORE_3_ENABLE_MASK;
> + break;
> + }
> +
> + /* CPU N is ready to start */
> + __raw_writel(reg, &src->scr);
> +
> + return 0;
> +}
> +
> +int is_core_valid(unsigned int nr)
> +{
> + if (nr >= CONFIG_NUM_CPUS)

And where is defined CONFIG_NUM_CPUS ?

Why do we have to configure it ? The number is related to the running
SOC and cannot be changed.

> + return 0;
> +
> + return 1;
> +}
> +
> +int cpu_disable(int nr)
> +{
> + uint32_t reg;
> + struct src *src = (struct src *)SRC_BASE_ADDR;
> +
> + reg = __raw_readl(&src->scr);
> +
> + switch (nr) {
> + case 1:
> + reg &= ~SRC_SCR_CORE_1_ENABLE_MASK;
> + break;
> +
> + case 2:
> + reg &= ~SRC_SCR_CORE_2_ENABLE_MASK;
> + break;
> +
> + case 3:
> + reg &= ~SRC_SCR_CORE_3_ENABLE_MASK;
> + break;
> + }
> +
> + /* Disable the CPU N */
> + __raw_writel(reg, &src->scr);
> +
> + return 0;
> +}
> diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h
> index 1f19727..3f8c2ee 100644
> --- a/arch/arm/include/asm/arch-mx6/imx-regs.h
> +++ b/arch/arm/include/asm/arch-mx6/imx-regs.h
> @@ -225,6 +225,19 @@
>
> extern void imx_get_mac_from_fuse(int dev_id, unsigned char *mac);
>
> +#define SRC_SCR_CORE_1_RESET_OFFSET 14
> +#define SRC_SCR_CORE_1_RESET_MASK (1<<SRC_SCR_CORE_1_RESET_OFFSET)
> +#define SRC_SCR_CORE_2_RESET_OFFSET 15
> +#define SRC_SCR_CORE_2_RESET_MASK (1<<SRC_SCR_CORE_2_RESET_OFFSET)
> +#define SRC_SCR_CORE_3_RESET_OFFSET 16
> +#define SRC_SCR_CORE_3_RESET_MASK (1<<SRC_SCR_CORE_3_RESET_OFFSET)
> +#define SRC_SCR_CORE_1_ENABLE_OFFSET 22
> +#define SRC_SCR_CORE_1_ENABLE_MASK (1<<SRC_SCR_CORE_1_ENABLE_OFFSET)
> +#define SRC_SCR_CORE_2_ENABLE_OFFSET 23
> +#define SRC_SCR_CORE_2_ENABLE_MASK (1<<SRC_SCR_CORE_2_ENABLE_OFFSET)
> +#define SRC_SCR_CORE_3_ENABLE_OFFSET 24
> +#define SRC_SCR_CORE_3_ENABLE_MASK (1<<SRC_SCR_CORE_3_ENABLE_OFFSET)
> +
> /* System Reset Controller (SRC) */
> struct src {
> u32 scr;

Best regards,
Stefano Babic

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