linux_dsm_epyc7002/arch/arm/mach-tegra/reset.c
Joseph Lo 5b795d051c ARM: tegra: add common resume handling code for LP1 resuming
Add support to the Tegra CPU reset vector to detect whether the CPU is
resuming from LP1 suspend state. If it is, branch to the LP1-specific
resume code.

When Tegra enters the LP1 suspend state, the SDRAM controller is placed
into a self-refresh state. For this reason, we must place the LP1 resume
code into IRAM, so that it is accessible before SDRAM access has been
re-enabled.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-08-12 12:22:38 -06:00

92 lines
2.3 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/init.h>
#include <linux/io.h>
#include <linux/cpumask.h>
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/hardware/cache-l2x0.h>
#include "iomap.h"
#include "irammap.h"
#include "reset.h"
#include "sleep.h"
#include "fuse.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_enable(void)
{
void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
void __iomem *evp_cpu_reset =
IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
u32 reg;
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);
/*
* NOTE: This must be the one and only write to the EVP CPU reset
* vector in the entire system.
*/
writel(TEGRA_IRAM_RESET_BASE + tegra_cpu_reset_handler_offset,
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.
*/
if (tegra_chip_id != TEGRA20) {
reg = readl(sb_ctrl);
reg |= 2;
writel(reg, sb_ctrl);
wmb();
}
is_enabled = true;
}
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_CODE_AREA;
__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
virt_to_phys((void *)tegra_resume);
#endif
tegra_cpu_reset_handler_enable();
}