arch/arm/mach-gemini/board-dt.c

Source file repositories/reference/linux-study-clean/arch/arm/mach-gemini/board-dt.c

File Facts

System
Linux kernel
Corpus path
arch/arm/mach-gemini/board-dt.c
Extension
.c
Size
1503 bytes
Lines
65
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Gemini Device Tree boot support
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/system_misc.h>
#include <asm/proc-fns.h>

#ifdef CONFIG_DEBUG_GEMINI
/* This is needed for LL-debug/earlyprintk/debug-macro.S */
static struct map_desc gemini_io_desc[] __initdata = {
	{
		.virtual = CONFIG_DEBUG_UART_VIRT,
		.pfn = __phys_to_pfn(CONFIG_DEBUG_UART_PHYS),
		.length = SZ_4K,
		.type = MT_DEVICE,
	},
};

static void __init gemini_map_io(void)
{
	iotable_init(gemini_io_desc, ARRAY_SIZE(gemini_io_desc));
}
#else
#define gemini_map_io NULL
#endif

static void gemini_idle(void)
{
	/*
	 * Because of broken hardware we have to enable interrupts or the CPU
	 * will never wakeup... Actually it is not very good to enable
	 * interrupts first since scheduler can miss a tick, but there is
	 * no other way around this. Platforms that needs it for power saving
	 * should enable it in init code, since by default it is
	 * disabled.
	 */

	/* FIXME: Enabling interrupts here is racy! */
	raw_local_irq_enable();
	cpu_do_idle();
	raw_local_irq_disable();
}

static void __init gemini_init_machine(void)
{
	arm_pm_idle = gemini_idle;
}

static const char *gemini_board_compat[] = {
	"cortina,gemini",
	NULL,
};

DT_MACHINE_START(GEMINI_DT, "Gemini (Device Tree)")
	.map_io		= gemini_map_io,
	.init_machine	= gemini_init_machine,
	.dt_compat	= gemini_board_compat,
MACHINE_END

Annotation

Implementation Notes