OpenWrt – Rev 1
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/*
* linux/arch/arm/mach-cns3xxx/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* Copyright 2012 Gateworks Corporation
* Chris Lang <clang@gateworks.com>
* Tim Harvey <tharvey@gateworks.com>
*
* 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/smp_scu.h>
#include <asm/unified.h>
#include <asm/fiq.h>
#include <mach/smp.h>
#include "cns3xxx.h"
static struct fiq_handler fh = {
.name = "cns3xxx-fiq"
};
struct fiq_req {
union {
struct {
const void *addr;
size_t size;
} map;
struct {
const void *addr;
size_t size;
} unmap;
struct {
const void *start;
const void *end;
} flush;
};
volatile uint flags;
void __iomem *reg;
} ____cacheline_aligned;
extern unsigned int fiq_number[2];
DEFINE_PER_CPU(struct fiq_req, fiq_data);
#define FIQ_ENABLED 0x80000000
#define FIQ_GENERATE 0x00010000
#define CNS3XXX_MAP_AREA 0x01000000
#define CNS3XXX_UNMAP_AREA 0x02000000
#define CNS3XXX_FLUSH_RANGE 0x03000000
extern void cns3xxx_secondary_startup(void);
extern unsigned char cns3xxx_fiq_start, cns3xxx_fiq_end;
#define SCU_CPU_STATUS 0x08
static void __iomem *scu_base;
static inline void cns3xxx_set_fiq_regs(unsigned int cpu)
{
struct pt_regs FIQ_regs;
struct fiq_req *fiq_req = &per_cpu(fiq_data, !cpu);
FIQ_regs.ARM_r8 = 0;
FIQ_regs.ARM_ip = (unsigned int)fiq_req;
FIQ_regs.ARM_sp = (int) MISC_FIQ_CPU(!cpu);
fiq_req->reg = MISC_FIQ_CPU(!cpu);
set_fiq_regs(&FIQ_regs);
}
static void __init cns3xxx_init_fiq(void)
{
void *fiqhandler_start;
unsigned int fiqhandler_length;
int ret;
fiqhandler_start = &cns3xxx_fiq_start;
fiqhandler_length = &cns3xxx_fiq_end - &cns3xxx_fiq_start;
ret = claim_fiq(&fh);
if (ret)
return;
set_fiq_handler(fiqhandler_start, fiqhandler_length);
}
/*
* Write pen_release in a way that is guaranteed to be visible to all
* observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
*/
static void write_pen_release(int val)
{
pen_release = val;
smp_wmb();
__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
}
static DEFINE_SPINLOCK(boot_lock);
static void cns3xxx_secondary_init(unsigned int cpu)
{
/*
* Setup Secondary Core FIQ regs
*/
cns3xxx_set_fiq_regs(1);
/*
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
write_pen_release(-1);
/*
* Synchronise with the boot thread.
*/
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
static int cns3xxx_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
/*
* Set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
* the holding pen - release it, then wait for it to flag
* that it has been released by resetting pen_release.
*
* Note that "pen_release" is the hardware CPU ID, whereas
* "cpu" is Linux's internal ID.
*/
write_pen_release(cpu);
/*
* Send the secondary CPU a soft interrupt, thereby causing
* the boot monitor to read the system wide flags register,
* and branch to the address found there.
*/
arch_send_wakeup_ipi_mask(cpumask_of(cpu));;
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
smp_rmb();
if (pen_release == -1)
break;
udelay(10);
}
/*
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init cns3xxx_smp_init_cpus(void)
{
unsigned int i, ncores;
unsigned int status;
scu_base = (void __iomem *) CNS3XXX_TC11MP_SCU_BASE_VIRT;
/* for CNS3xxx SCU_CPU_STATUS must be examined instead of SCU_CONFIGURATION
* used in scu_get_core_count
*/
status = __raw_readl(scu_base + SCU_CPU_STATUS);
for (i = 0; i < NR_CPUS+1; i++) {
if (((status >> (i*2)) & 0x3) == 0)
set_cpu_possible(i, true);
else
break;
}
ncores = i;
}
static void __init cns3xxx_smp_prepare_cpus(unsigned int max_cpus)
{
/*
* enable SCU
*/
scu_enable(scu_base);
/*
* Write the address of secondary startup into the
* system-wide flags register. The boot monitor waits
* until it receives a soft interrupt, and then the
* secondary CPU branches to this address.
*/
__raw_writel(virt_to_phys(cns3xxx_secondary_startup),
(void __iomem *)(CNS3XXX_MISC_BASE_VIRT + 0x0600));
/*
* Setup FIQ's for main cpu
*/
cns3xxx_init_fiq();
cns3xxx_set_fiq_regs(0);
}
extern void v6_dma_map_area(const void *, size_t, int);
extern void v6_dma_unmap_area(const void *, size_t, int);
extern void v6_dma_flush_range(const void *, const void *);
extern void v6_flush_kern_dcache_area(void *, size_t);
void fiq_dma_map_area(const void *addr, size_t size, int dir)
{
unsigned long flags;
struct fiq_req *req;
raw_local_irq_save(flags);
/* currently, not possible to take cpu0 down, so only check cpu1 */
if (!cpu_online(1)) {
raw_local_irq_restore(flags);
v6_dma_map_area(addr, size, dir);
return;
}
req = this_cpu_ptr(&fiq_data);
req->map.addr = addr;
req->map.size = size;
req->flags = dir | CNS3XXX_MAP_AREA;
smp_mb();
writel_relaxed(FIQ_GENERATE, req->reg);
v6_dma_map_area(addr, size, dir);
while (req->flags)
barrier();
raw_local_irq_restore(flags);
}
void fiq_dma_unmap_area(const void *addr, size_t size, int dir)
{
unsigned long flags;
struct fiq_req *req;
raw_local_irq_save(flags);
/* currently, not possible to take cpu0 down, so only check cpu1 */
if (!cpu_online(1)) {
raw_local_irq_restore(flags);
v6_dma_unmap_area(addr, size, dir);
return;
}
req = this_cpu_ptr(&fiq_data);
req->unmap.addr = addr;
req->unmap.size = size;
req->flags = dir | CNS3XXX_UNMAP_AREA;
smp_mb();
writel_relaxed(FIQ_GENERATE, req->reg);
v6_dma_unmap_area(addr, size, dir);
while (req->flags)
barrier();
raw_local_irq_restore(flags);
}
void fiq_dma_flush_range(const void *start, const void *end)
{
unsigned long flags;
struct fiq_req *req;
raw_local_irq_save(flags);
/* currently, not possible to take cpu0 down, so only check cpu1 */
if (!cpu_online(1)) {
raw_local_irq_restore(flags);
v6_dma_flush_range(start, end);
return;
}
req = this_cpu_ptr(&fiq_data);
req->flush.start = start;
req->flush.end = end;
req->flags = CNS3XXX_FLUSH_RANGE;
smp_mb();
writel_relaxed(FIQ_GENERATE, req->reg);
v6_dma_flush_range(start, end);
while (req->flags)
barrier();
raw_local_irq_restore(flags);
}
void fiq_flush_kern_dcache_area(void *addr, size_t size)
{
fiq_dma_flush_range(addr, addr + size);
}
struct smp_operations cns3xxx_smp_ops __initdata = {
.smp_init_cpus = cns3xxx_smp_init_cpus,
.smp_prepare_cpus = cns3xxx_smp_prepare_cpus,
.smp_secondary_init = cns3xxx_secondary_init,
.smp_boot_secondary = cns3xxx_boot_secondary,
};