linux_dsm_epyc7002/arch/arm/mach-tegra/platsmp.c
Peter De Schrijver b36ab9754e ARM: tegra: rework Tegra secondary CPU core bringup
Prepare the Tegra secondary CPU core bringup code for other Tegra variants.
The reset handler is also generalized to allow for future introduction of
powersaving modes which turn off the CPU cores.

Based on work by:

Scott Williams <scwilliams@nvidia.com>
Chris Johnson <cwj@nvidia.com>
Colin Cross <ccross@android.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2012-02-26 14:44:44 -08:00

141 lines
3.4 KiB
C

/*
* linux/arch/arm/mach-tegra/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* Copyright (C) 2009 Palm
* 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/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/hardware/gic.h>
#include <asm/mach-types.h>
#include <asm/smp_scu.h>
#include <mach/iomap.h>
#include "fuse.h"
#include "flowctrl.h"
#include "reset.h"
extern void tegra_secondary_startup(void);
static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
#define EVP_CPU_RESET_VECTOR \
(IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)
#define CLK_RST_CONTROLLER_CLK_CPU_CMPLX \
(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x4c)
#define CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET \
(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x340)
#define CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR \
(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x344)
#define CPU_CLOCK(cpu) (0x1<<(8+cpu))
#define CPU_RESET(cpu) (0x1111ul<<(cpu))
void __cpuinit platform_secondary_init(unsigned int cpu)
{
/*
* if any interrupts are already enabled for the primary
* core (e.g. timer irq), then they will not have been enabled
* for us: do so
*/
gic_secondary_init(0);
}
static int tegra20_power_up_cpu(unsigned int cpu)
{
u32 reg;
/* Enable the CPU clock. */
reg = readl(CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
writel(reg & ~CPU_CLOCK(cpu), CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
barrier();
reg = readl(CLK_RST_CONTROLLER_CLK_CPU_CMPLX);
/* Clear flow controller CSR. */
flowctrl_write_cpu_csr(cpu, 0);
return 0;
}
int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int status;
/* Force the CPU into reset. The CPU must remain in reset when the
* flow controller state is cleared (which will cause the flow
* controller to stop driving reset if the CPU has been power-gated
* via the flow controller). This will have no effect on first boot
* of the CPU since it should already be in reset.
*/
writel(CPU_RESET(cpu), CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET);
dmb();
/*
* Unhalt the CPU. If the flow controller was used to power-gate the
* CPU this will cause the flow controller to stop driving reset.
* The CPU will remain in reset because the clock and reset block
* is now driving reset.
*/
flowctrl_write_cpu_halt(cpu, 0);
switch (tegra_chip_id) {
case TEGRA20:
status = tegra20_power_up_cpu(cpu);
break;
default:
status = -EINVAL;
break;
}
if (status)
goto done;
/* Take the CPU out of reset. */
writel(CPU_RESET(cpu), CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR);
wmb();
done:
return status;
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
void __init smp_init_cpus(void)
{
unsigned int i, ncores = scu_get_core_count(scu_base);
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
ncores, nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
set_smp_cross_call(gic_raise_softirq);
}
void __init platform_smp_prepare_cpus(unsigned int max_cpus)
{
tegra_cpu_reset_handler_init();
scu_enable(scu_base);
}