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sh: Force boot CPU in to light sleep mode for SH-X3 SMP.
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All of the secondary CPUs are forced in to light sleep mode, but we were
missing the same initialization for the boot CPU. This resulted in
inconsistent sleep modes depending on which CPU we were on, confusing the
idle loop when not polling.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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Paul Mundt committed Oct 16, 2009
1 parent abeaf33 commit 94eab0b
Showing 1 changed file with 19 additions and 18 deletions.
37 changes: 19 additions & 18 deletions arch/sh/kernel/cpu/sh4a/smp-shx3.c
Original file line number Diff line number Diff line change
Expand Up @@ -14,16 +14,23 @@
#include <linux/interrupt.h>
#include <linux/io.h>

#define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
#define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))

#define STBCR_MSTP 0x00000001
#define STBCR_RESET 0x00000002
#define STBCR_LTSLP 0x80000000

static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
{
unsigned int message = (unsigned int)(long)arg;
unsigned int cpu = hard_smp_processor_id();
unsigned int offs = 4 * cpu;
unsigned int x;

x = ctrl_inl(0xfe410070 + offs); /* C0INITICI..CnINTICI */
x = __raw_readl(0xfe410070 + offs); /* C0INITICI..CnINTICI */
x &= (1 << (message << 2));
ctrl_outl(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */
__raw_writel(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */

smp_message_recv(message);

Expand All @@ -37,6 +44,9 @@ void __init plat_smp_setup(void)

init_cpu_possible(cpumask_of(cpu));

/* Enable light sleep for the boot CPU */
__raw_writel(__raw_readl(STBCR_REG(cpu)) | STBCR_LTSLP, STBCR_REG(cpu));

__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;

Expand Down Expand Up @@ -66,32 +76,23 @@ void __init plat_prepare_cpus(unsigned int max_cpus)
"IPI", (void *)(long)i);
}

#define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
#define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))

#define STBCR_MSTP 0x00000001
#define STBCR_RESET 0x00000002
#define STBCR_LTSLP 0x80000000

#define STBCR_AP_VAL (STBCR_RESET | STBCR_LTSLP)

void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
{
ctrl_outl(entry_point, RESET_REG(cpu));
__raw_writel(entry_point, RESET_REG(cpu));

if (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
ctrl_outl(STBCR_MSTP, STBCR_REG(cpu));
if (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
__raw_writel(STBCR_MSTP, STBCR_REG(cpu));

while (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
cpu_relax();

/* Start up secondary processor by sending a reset */
ctrl_outl(STBCR_AP_VAL, STBCR_REG(cpu));
__raw_writel(STBCR_RESET | STBCR_LTSLP, STBCR_REG(cpu));
}

int plat_smp_processor_id(void)
{
return ctrl_inl(0xff000048); /* CPIDR */
return __raw_readl(0xff000048); /* CPIDR */
}

void plat_send_ipi(unsigned int cpu, unsigned int message)
Expand All @@ -100,5 +101,5 @@ void plat_send_ipi(unsigned int cpu, unsigned int message)

BUG_ON(cpu >= 4);

ctrl_outl(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
__raw_writel(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
}

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