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linux-next/arch/arm/mach-tegra/reset.c
Thierry Reding c090e11163 ARM: tegra: Always lock the CPU reset vector
Currently the reset vector is not locked on Tegra20 because the hardware
doesn't support it. However in order not to depend on the chip ID, which
becomes available only later in the boot process, we set the bit anyway.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-07-17 14:58:42 +02:00

109 lines
2.7 KiB
C

/*
* arch/arm/mach-tegra/reset.c
*
* Copyright (C) 2011,2012 NVIDIA Corporation.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/bitops.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/io.h>
#include <soc/tegra/fuse.h>
#include <asm/cacheflush.h>
#include <asm/firmware.h>
#include <asm/hardware/cache-l2x0.h>
#include "iomap.h"
#include "irammap.h"
#include "reset.h"
#include "sleep.h"
#define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
TEGRA_IRAM_RESET_HANDLER_OFFSET)
static bool is_enabled;
static void __init tegra_cpu_reset_handler_set(const u32 reset_address)
{
void __iomem *evp_cpu_reset =
IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
u32 reg;
/*
* NOTE: This must be the one and only write to the EVP CPU reset
* vector in the entire system.
*/
writel(reset_address, evp_cpu_reset);
wmb();
reg = readl(evp_cpu_reset);
/*
* Prevent further modifications to the physical reset vector.
* NOTE: Has no effect on chips prior to Tegra30.
*/
reg = readl(sb_ctrl);
reg |= 2;
writel(reg, sb_ctrl);
wmb();
}
static void __init tegra_cpu_reset_handler_enable(void)
{
void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
const u32 reset_address = TEGRA_IRAM_RESET_BASE +
tegra_cpu_reset_handler_offset;
int err;
BUG_ON(is_enabled);
BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);
memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start,
tegra_cpu_reset_handler_size);
err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
switch (err) {
case -ENOSYS:
tegra_cpu_reset_handler_set(reset_address);
/* pass-through */
case 0:
is_enabled = true;
break;
default:
pr_crit("Cannot set CPU reset handler: %d\n", err);
BUG();
}
}
void __init tegra_cpu_reset_handler_init(void)
{
#ifdef CONFIG_SMP
__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
*((u32 *)cpu_possible_mask);
__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_SECONDARY] =
virt_to_phys((void *)tegra_secondary_startup);
#endif
#ifdef CONFIG_PM_SLEEP
__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP1] =
TEGRA_IRAM_LPx_RESUME_AREA;
__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
virt_to_phys((void *)tegra_resume);
#endif
tegra_cpu_reset_handler_enable();
}