linux/arch/arm/mach-vexpress/ct-ca9x4.c
Stephen Boyd 7fa22bd546 ARM: 6993/1: platsmp: Allow secondary cpu hotplug with maxcpus=1
If an ARM system has multiple cpus in the same socket and the
kernel is booted with maxcpus=1, secondary cpus are possible but
not present due to how platform_smp_prepare_cpus() is called.
Since most typical ARM processors don't actually support physical
hotplug, initialize the present map to be equal to the possible
map in generic ARM SMP code. Also, always call
platform_smp_prepare_cpus() as long as max_cpus is non-zero (0
means no SMP) to allow platform code to do any SMP setup.

After applying this patch it's possible to boot an ARM system
with maxcpus=1 on the command line and then hotplug in secondary
cpus via sysfs. This is more in line with how x86 does things.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 14:45:07 +01:00

248 lines
5.4 KiB
C

/*
* Versatile Express Core Tile Cortex A9x4 Support
*/
#include <linux/init.h>
#include <linux/gfp.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/amba/bus.h>
#include <linux/amba/clcd.h>
#include <linux/clkdev.h>
#include <asm/hardware/arm_timer.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/hardware/gic.h>
#include <asm/pmu.h>
#include <asm/smp_scu.h>
#include <asm/smp_twd.h>
#include <mach/ct-ca9x4.h>
#include <asm/hardware/timer-sp.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#include "core.h"
#include <mach/motherboard.h>
#include <plat/clcd.h>
#define V2M_PA_CS7 0x10000000
static struct map_desc ct_ca9x4_io_desc[] __initdata = {
{
.virtual = __MMIO_P2V(CT_CA9X4_MPIC),
.pfn = __phys_to_pfn(CT_CA9X4_MPIC),
.length = SZ_16K,
.type = MT_DEVICE,
}, {
.virtual = __MMIO_P2V(CT_CA9X4_SP804_TIMER),
.pfn = __phys_to_pfn(CT_CA9X4_SP804_TIMER),
.length = SZ_4K,
.type = MT_DEVICE,
}, {
.virtual = __MMIO_P2V(CT_CA9X4_L2CC),
.pfn = __phys_to_pfn(CT_CA9X4_L2CC),
.length = SZ_4K,
.type = MT_DEVICE,
},
};
static void __init ct_ca9x4_map_io(void)
{
#ifdef CONFIG_LOCAL_TIMERS
twd_base = MMIO_P2V(A9_MPCORE_TWD);
#endif
iotable_init(ct_ca9x4_io_desc, ARRAY_SIZE(ct_ca9x4_io_desc));
}
static void __init ct_ca9x4_init_irq(void)
{
gic_init(0, 29, MMIO_P2V(A9_MPCORE_GIC_DIST),
MMIO_P2V(A9_MPCORE_GIC_CPU));
}
#if 0
static void __init ct_ca9x4_timer_init(void)
{
writel(0, MMIO_P2V(CT_CA9X4_TIMER0) + TIMER_CTRL);
writel(0, MMIO_P2V(CT_CA9X4_TIMER1) + TIMER_CTRL);
sp804_clocksource_init(MMIO_P2V(CT_CA9X4_TIMER1), "ct-timer1");
sp804_clockevents_init(MMIO_P2V(CT_CA9X4_TIMER0), IRQ_CT_CA9X4_TIMER0,
"ct-timer0");
}
static struct sys_timer ct_ca9x4_timer = {
.init = ct_ca9x4_timer_init,
};
#endif
static void ct_ca9x4_clcd_enable(struct clcd_fb *fb)
{
v2m_cfg_write(SYS_CFG_MUXFPGA | SYS_CFG_SITE_DB1, 0);
v2m_cfg_write(SYS_CFG_DVIMODE | SYS_CFG_SITE_DB1, 2);
}
static int ct_ca9x4_clcd_setup(struct clcd_fb *fb)
{
unsigned long framesize = 1024 * 768 * 2;
fb->panel = versatile_clcd_get_panel("XVGA");
if (!fb->panel)
return -EINVAL;
return versatile_clcd_setup_dma(fb, framesize);
}
static struct clcd_board ct_ca9x4_clcd_data = {
.name = "CT-CA9X4",
.caps = CLCD_CAP_5551 | CLCD_CAP_565,
.check = clcdfb_check,
.decode = clcdfb_decode,
.enable = ct_ca9x4_clcd_enable,
.setup = ct_ca9x4_clcd_setup,
.mmap = versatile_clcd_mmap_dma,
.remove = versatile_clcd_remove_dma,
};
static AMBA_DEVICE(clcd, "ct:clcd", CT_CA9X4_CLCDC, &ct_ca9x4_clcd_data);
static AMBA_DEVICE(dmc, "ct:dmc", CT_CA9X4_DMC, NULL);
static AMBA_DEVICE(smc, "ct:smc", CT_CA9X4_SMC, NULL);
static AMBA_DEVICE(gpio, "ct:gpio", CT_CA9X4_GPIO, NULL);
static struct amba_device *ct_ca9x4_amba_devs[] __initdata = {
&clcd_device,
&dmc_device,
&smc_device,
&gpio_device,
};
static long ct_round(struct clk *clk, unsigned long rate)
{
return rate;
}
static int ct_set(struct clk *clk, unsigned long rate)
{
return v2m_cfg_write(SYS_CFG_OSC | SYS_CFG_SITE_DB1 | 1, rate);
}
static const struct clk_ops osc1_clk_ops = {
.round = ct_round,
.set = ct_set,
};
static struct clk osc1_clk = {
.ops = &osc1_clk_ops,
.rate = 24000000,
};
static struct clk ct_sp804_clk = {
.rate = 1000000,
};
static struct clk_lookup lookups[] = {
{ /* CLCD */
.dev_id = "ct:clcd",
.clk = &osc1_clk,
}, { /* SP804 timers */
.dev_id = "sp804",
.con_id = "ct-timer0",
.clk = &ct_sp804_clk,
}, { /* SP804 timers */
.dev_id = "sp804",
.con_id = "ct-timer1",
.clk = &ct_sp804_clk,
},
};
static struct resource pmu_resources[] = {
[0] = {
.start = IRQ_CT_CA9X4_PMU_CPU0,
.end = IRQ_CT_CA9X4_PMU_CPU0,
.flags = IORESOURCE_IRQ,
},
[1] = {
.start = IRQ_CT_CA9X4_PMU_CPU1,
.end = IRQ_CT_CA9X4_PMU_CPU1,
.flags = IORESOURCE_IRQ,
},
[2] = {
.start = IRQ_CT_CA9X4_PMU_CPU2,
.end = IRQ_CT_CA9X4_PMU_CPU2,
.flags = IORESOURCE_IRQ,
},
[3] = {
.start = IRQ_CT_CA9X4_PMU_CPU3,
.end = IRQ_CT_CA9X4_PMU_CPU3,
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device pmu_device = {
.name = "arm-pmu",
.id = ARM_PMU_DEVICE_CPU,
.num_resources = ARRAY_SIZE(pmu_resources),
.resource = pmu_resources,
};
static void __init ct_ca9x4_init_early(void)
{
clkdev_add_table(lookups, ARRAY_SIZE(lookups));
}
static void __init ct_ca9x4_init(void)
{
int i;
#ifdef CONFIG_CACHE_L2X0
void __iomem *l2x0_base = MMIO_P2V(CT_CA9X4_L2CC);
/* set RAM latencies to 1 cycle for this core tile. */
writel(0, l2x0_base + L2X0_TAG_LATENCY_CTRL);
writel(0, l2x0_base + L2X0_DATA_LATENCY_CTRL);
l2x0_init(l2x0_base, 0x00400000, 0xfe0fffff);
#endif
for (i = 0; i < ARRAY_SIZE(ct_ca9x4_amba_devs); i++)
amba_device_register(ct_ca9x4_amba_devs[i], &iomem_resource);
platform_device_register(&pmu_device);
}
#ifdef CONFIG_SMP
static void ct_ca9x4_init_cpu_map(void)
{
int i, ncores = scu_get_core_count(MMIO_P2V(A9_MPCORE_SCU));
for (i = 0; i < ncores; ++i)
set_cpu_possible(i, true);
set_smp_cross_call(gic_raise_softirq);
}
static void ct_ca9x4_smp_enable(unsigned int max_cpus)
{
scu_enable(MMIO_P2V(A9_MPCORE_SCU));
}
#endif
struct ct_desc ct_ca9x4_desc __initdata = {
.id = V2M_CT_ID_CA9,
.name = "CA9x4",
.map_io = ct_ca9x4_map_io,
.init_early = ct_ca9x4_init_early,
.init_irq = ct_ca9x4_init_irq,
.init_tile = ct_ca9x4_init,
#ifdef CONFIG_SMP
.init_cpu_map = ct_ca9x4_init_cpu_map,
.smp_enable = ct_ca9x4_smp_enable,
#endif
};