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ARM: vexpress: Simplify SMP operations for DT-powered system

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As all cores must be properly described in the Device Tree,
there is no point in getting their numbers from SCU on
A5/A9 platforms. This significantly simplifies the code,
removing the need for flat-tree scanning and early static
mapping.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
This commit is contained in:
Pawel Moll 2013-09-17 18:30:58 +01:00
parent dcdea6295d
commit d2606f81d5
3 changed files with 41 additions and 126 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/arm/mach-vexpress/core.h
View File

@ -4,10 +4,9 @@
/* Tile's peripherals static mappings should start here */
#define V2T_PERIPH 0xf8200000
void vexpress_dt_smp_map_io(void);
bool vexpress_smp_init_ops(void);
extern struct smp_operations vexpress_smp_ops;
extern struct smp_operations vexpress_smp_dt_ops;
extern void vexpress_cpu_die(unsigned int cpu);

158
arch/arm/mach-vexpress/platsmp.c
View File

@ -12,8 +12,7 @@
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_address.h>
#include <linux/vexpress.h>
#include <asm/mcpm.h>
@ -26,125 +25,13 @@
#include "core.h"
#if defined(CONFIG_OF)
static enum {
GENERIC_SCU,
CORTEX_A9_SCU,
} vexpress_dt_scu __initdata = GENERIC_SCU;
static struct map_desc vexpress_dt_cortex_a9_scu_map __initdata = {
.virtual = V2T_PERIPH,
/* .pfn set in vexpress_dt_init_cortex_a9_scu() */
.length = SZ_128,
.type = MT_DEVICE,
};
static void *vexpress_dt_cortex_a9_scu_base __initdata;
const static char *vexpress_dt_cortex_a9_match[] __initconst = {
"arm,cortex-a5-scu",
"arm,cortex-a9-scu",
NULL
};
static int __init vexpress_dt_find_scu(unsigned long node,
const char *uname, int depth, void *data)
{
if (of_flat_dt_match(node, vexpress_dt_cortex_a9_match)) {
phys_addr_t phys_addr;
__be32 *reg = of_get_flat_dt_prop(node, "reg", NULL);
if (WARN_ON(!reg))
return -EINVAL;
phys_addr = be32_to_cpup(reg);
vexpress_dt_scu = CORTEX_A9_SCU;
vexpress_dt_cortex_a9_scu_map.pfn = __phys_to_pfn(phys_addr);
iotable_init(&vexpress_dt_cortex_a9_scu_map, 1);
vexpress_dt_cortex_a9_scu_base = ioremap(phys_addr, SZ_256);
if (WARN_ON(!vexpress_dt_cortex_a9_scu_base))
return -EFAULT;
}
return 0;
}
void __init vexpress_dt_smp_map_io(void)
{
if (initial_boot_params)
WARN_ON(of_scan_flat_dt(vexpress_dt_find_scu, NULL));
}
static void __init vexpress_dt_smp_init_cpus(void)
{
int ncores = 0, i;
switch (vexpress_dt_scu) {
case GENERIC_SCU:
return;
case CORTEX_A9_SCU:
ncores = scu_get_core_count(vexpress_dt_cortex_a9_scu_base);
break;
default:
WARN_ON(1);
break;
}
if (ncores < 2)
return;
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);
}
static void __init vexpress_dt_smp_prepare_cpus(unsigned int max_cpus)
{
switch (vexpress_dt_scu) {
case GENERIC_SCU:
break;
case CORTEX_A9_SCU:
scu_enable(vexpress_dt_cortex_a9_scu_base);
break;
default:
WARN_ON(1);
break;
}
}
#else
static void __init vexpress_dt_smp_init_cpus(void)
{
WARN_ON(1);
}
void __init vexpress_dt_smp_prepare_cpus(unsigned int max_cpus)
{
WARN_ON(1);
}
#endif
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init vexpress_smp_init_cpus(void)
{
if (ct_desc)
ct_desc->init_cpu_map();
else
vexpress_dt_smp_init_cpus();
ct_desc->init_cpu_map();
}
static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
@ -153,10 +40,7 @@ static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
if (ct_desc)
ct_desc->smp_enable(max_cpus);
else
vexpress_dt_smp_prepare_cpus(max_cpus);
ct_desc->smp_enable(max_cpus);
/*
* Write the address of secondary startup into the
@ -194,3 +78,39 @@ bool __init vexpress_smp_init_ops(void)
#endif
return false;
}
#if defined(CONFIG_OF)
static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
{ .compatible = "arm,cortex-a5-scu", },
{ .compatible = "arm,cortex-a9-scu", },
{}
};
static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
{
struct device_node *scu = of_find_matching_node(NULL,
vexpress_smp_dt_scu_match);
if (scu)
scu_enable(of_iomap(scu, 0));
/*
* 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.
*/
vexpress_flags_set(virt_to_phys(versatile_secondary_startup));
}
struct smp_operations __initdata vexpress_smp_dt_ops = {
.smp_prepare_cpus = vexpress_smp_dt_prepare_cpus,
.smp_secondary_init = versatile_secondary_init,
.smp_boot_secondary = versatile_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = vexpress_cpu_die,
#endif
};
#endif

6
arch/arm/mach-vexpress/v2m.c
View File

@ -400,10 +400,6 @@ void __init v2m_dt_map_io(void)
iotable_init(&v2m_rs1_io_desc, 1);
else
iotable_init(v2m_io_desc, ARRAY_SIZE(v2m_io_desc));
#if defined(CONFIG_SMP)
vexpress_dt_smp_map_io();
#endif
}
void __init v2m_dt_init_early(void)
@ -434,7 +430,7 @@ static const char * const v2m_dt_match[] __initconst = {
DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express")
.dt_compat = v2m_dt_match,
.smp = smp_ops(vexpress_smp_ops),
.smp = smp_ops(vexpress_smp_dt_ops),
.smp_init = smp_init_ops(vexpress_smp_init_ops),
.map_io = v2m_dt_map_io,
.init_early = v2m_dt_init_early,