diff mbox

[v1,8/8] ARM: tegra: support for secondary cores on Tegra30

Message ID 1327597641-7519-9-git-send-email-pdeschrijver@nvidia.com
State Superseded, archived
Headers show

Commit Message

Peter De Schrijver Jan. 26, 2012, 5:07 p.m. UTC
Add support for bringing up secondary cores on Tegra30. On Tegra30 secondary
CPU cores are powergated, so we need to turn on the domains before we can bring
the CPU cores online. Bringing secondary cores online happens early during the
ssytem boot, so we call powergating initialization from platform early_init
function.

Based on work by:

Scott Williams <scwilliams@nvidia.com>
Colin Cross <ccross@android.com>
Alex Frid <afrid@nvidia.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
---
 arch/arm/mach-tegra/headsmp.S |   32 +++++++++++++++++++++++++
 arch/arm/mach-tegra/platsmp.c |   52 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 83 insertions(+), 1 deletions(-)

Comments

Stephen Warren Jan. 26, 2012, 8:44 p.m. UTC | #1
Peter De Schrijver wrote at Thursday, January 26, 2012 10:07 AM:
> Add support for bringing up secondary cores on Tegra30. On Tegra30 secondary
> CPU cores are powergated, so we need to turn on the domains before we can bring
> the CPU cores online. Bringing secondary cores online happens early during the
> ssytem boot, so we call powergating initialization from platform early_init
> function.
> 
> Based on work by:
> 
> Scott Williams <scwilliams@nvidia.com>
> Colin Cross <ccross@android.com>
> Alex Frid <afrid@nvidia.com>
> 
> Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>

The series,

Acked-by: Stephen Warren <swarren@nvidia.com>

(I already saw this a few times before Peter posted it, so any concerns
I had have been fixed. Still, I'm not very familiar with this part of
the code, so it'd be awesome if e.g. Colin could review this too)

Tested-by: Stephen Warren <swarren@nvidia.com>

(Booted Tegra20 Harmony, validated 2 CPUs found in dmesg during boot,
validated top showed 2 CPUs being actively used. Booted Tegra30 Cardhu,
validated 4 CPUs found in dmesg during boot, but didn't validate anything
from user-space since the SD controller doesn't work yet and I don't have
an initrd set up to test with).
Murali N Jan. 27, 2012, 5:58 a.m. UTC | #2
On Thu, Jan 26, 2012 at 10:37 PM, Peter De Schrijver
<pdeschrijver@nvidia.com> wrote:
>
> Add support for bringing up secondary cores on Tegra30. On Tegra30 secondary
> CPU cores are powergated, so we need to turn on the domains before we can bring
> the CPU cores online. Bringing secondary cores online happens early during the
> ssytem boot, so we call powergating initialization from platform early_init

small spelling correction "system"

> function.
>
> Based on work by:
>
> Scott Williams <scwilliams@nvidia.com>
> Colin Cross <ccross@android.com>
> Alex Frid <afrid@nvidia.com>
>
> Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
> ---
>  arch/arm/mach-tegra/headsmp.S |   32 +++++++++++++++++++++++++
>  arch/arm/mach-tegra/platsmp.c |   52 ++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 83 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S
> index bb13e22..925c4a0 100644
> --- a/arch/arm/mach-tegra/headsmp.S
> +++ b/arch/arm/mach-tegra/headsmp.S
> @@ -188,6 +188,38 @@ __die:
>        str     r1, [r7, #0x340]                @ CLK_RST_CPU_CMPLX_SET
>  #endif
>  1:
> +#ifdef CONFIG_ARCH_TEGRA_3x_SOC
> +       mov32   r6, TEGRA_FLOW_CTRL_BASE
> +
> +       cmp     r10, #0
> +       moveq   r1, #FLOW_CTRL_HALT_CPU0_EVENTS
> +       moveq   r2, #FLOW_CTRL_CPU0_CSR
> +       movne   r1, r10, lsl #3
> +       addne   r2, r1, #(FLOW_CTRL_CPU1_CSR-8)
> +       addne   r1, r1, #(FLOW_CTRL_HALT_CPU1_EVENTS-8)
> +
> +       /* Clear CPU "event" and "interrupt" flags and power gate
> +          it when halting but not before it is in the "WFI" state. */
> +       ldr     r0, [r6, +r2]
> +       orr     r0, r0, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
> +       orr     r0, r0, #FLOW_CTRL_CSR_ENABLE
> +       str     r0, [r6, +r2]
> +
> +       /* Unconditionally halt this CPU */
> +       mov     r0, #FLOW_CTRL_WAITEVENT
> +       str     r0, [r6, +r1]
> +       ldr     r0, [r6, +r1]                   @ memory barrier
> +
> +       dsb
> +       isb
> +       wfi                                     @ CPU should be power gated here
> +
> +       /* If the CPU didn't power gate above just kill it's clock. */
> +
> +       mov     r0, r11, lsl #8
> +       str     r0, [r7, #348]                  @ CLK_CPU_CMPLX_SET
> +#endif
> +
>        /* If the CPU still isn't dead, just spin here. */
>        b       .
>  ENDPROC(__tegra_cpu_reset_handler)
> diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
> index fa1178d..672a751 100644
> --- a/arch/arm/mach-tegra/platsmp.c
> +++ b/arch/arm/mach-tegra/platsmp.c
> @@ -24,7 +24,9 @@
>  #include <asm/mach-types.h>
>  #include <asm/smp_scu.h>
>
> +#include <mach/clk.h>
>  #include <mach/iomap.h>
> +#include <mach/powergate.h>
>
>  #include "chipid.h"
>  #include "flowctrl.h"
> @@ -42,6 +44,8 @@ static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
>        (IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x340)
>  #define CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR \
>        (IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x344)
> +#define CLK_RST_CONTROLLER_CLK_CPU_CMPLX_CLR \
> +       (IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x34c)
>
>  #define CPU_CLOCK(cpu) (0x1<<(8+cpu))
>  #define CPU_RESET(cpu) (0x1111ul<<(cpu))
> @@ -73,11 +77,54 @@ static int tegra20_power_up_cpu(unsigned int cpu)
>        return 0;
>  }
>
> +static int tegra30_power_up_cpu(unsigned int cpu)
> +{
> +       u32 reg;
> +       int ret, pwrgateid;
> +       unsigned long timeout;
> +
> +       pwrgateid = tegra_cpu_powergate_id(cpu);
> +       if (pwrgateid < 0)
> +               return pwrgateid;
> +
> +       /* If this is the first boot, toggle powergates directly. */
> +       if (!tegra_powergate_is_powered(pwrgateid)) {
> +               ret = tegra_powergate_power_on(pwrgateid);
> +               if (ret)
> +                       return ret;
> +
> +               /* Wait for the power to come up. */
> +               timeout = jiffies + 10*HZ;
> +               do {
> +                       if (tegra_powergate_is_powered(pwrgateid))
> +                               goto remove_clamps;
> +                       udelay(10);
> +               } while (time_before(jiffies, timeout));
> +               return -ETIMEDOUT;
> +       }
> +
> +remove_clamps:
> +       /* CPU partition is powered. Enable the CPU clock. */
> +       writel(CPU_CLOCK(cpu), CLK_RST_CONTROLLER_CLK_CPU_CMPLX_CLR);
> +       reg = readl(CLK_RST_CONTROLLER_CLK_CPU_CMPLX_CLR);
> +       udelay(10);
> +
> +       /* Remove I/O clamps. */
> +       ret = tegra_powergate_remove_clamping(pwrgateid);
> +       udelay(10);
> +
> +       /* 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
> +       /*
> +        * 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
> @@ -98,6 +145,9 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
>        case TEGRA20:
>                status = tegra20_power_up_cpu(cpu);
>                break;
> +       case TEGRA30:
> +               status = tegra30_power_up_cpu(cpu);
> +               break;
>        default:
>                status = -EINVAL;
>                break;
> --
> 1.7.7.rc0.72.g4b5ea.dirty
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel




--
Regards,
Murali N
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diff mbox

Patch

diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S
index bb13e22..925c4a0 100644
--- a/arch/arm/mach-tegra/headsmp.S
+++ b/arch/arm/mach-tegra/headsmp.S
@@ -188,6 +188,38 @@  __die:
 	str	r1, [r7, #0x340]		@ CLK_RST_CPU_CMPLX_SET
 #endif
 1:
+#ifdef CONFIG_ARCH_TEGRA_3x_SOC
+	mov32	r6, TEGRA_FLOW_CTRL_BASE
+
+	cmp	r10, #0
+	moveq	r1, #FLOW_CTRL_HALT_CPU0_EVENTS
+	moveq	r2, #FLOW_CTRL_CPU0_CSR
+	movne	r1, r10, lsl #3
+	addne	r2, r1, #(FLOW_CTRL_CPU1_CSR-8)
+	addne	r1, r1, #(FLOW_CTRL_HALT_CPU1_EVENTS-8)
+
+	/* Clear CPU "event" and "interrupt" flags and power gate
+	   it when halting but not before it is in the "WFI" state. */
+	ldr	r0, [r6, +r2]
+	orr	r0, r0, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
+	orr	r0, r0, #FLOW_CTRL_CSR_ENABLE
+	str	r0, [r6, +r2]
+
+	/* Unconditionally halt this CPU */
+	mov	r0, #FLOW_CTRL_WAITEVENT
+	str	r0, [r6, +r1]
+	ldr	r0, [r6, +r1]			@ memory barrier
+
+	dsb
+	isb
+	wfi					@ CPU should be power gated here
+
+	/* If the CPU didn't power gate above just kill it's clock. */
+
+	mov	r0, r11, lsl #8
+	str	r0, [r7, #348]			@ CLK_CPU_CMPLX_SET
+#endif
+
 	/* If the CPU still isn't dead, just spin here. */
 	b	.
 ENDPROC(__tegra_cpu_reset_handler)
diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
index fa1178d..672a751 100644
--- a/arch/arm/mach-tegra/platsmp.c
+++ b/arch/arm/mach-tegra/platsmp.c
@@ -24,7 +24,9 @@ 
 #include <asm/mach-types.h>
 #include <asm/smp_scu.h>
 
+#include <mach/clk.h>
 #include <mach/iomap.h>
+#include <mach/powergate.h>
 
 #include "chipid.h"
 #include "flowctrl.h"
@@ -42,6 +44,8 @@  static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
 	(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x340)
 #define CLK_RST_CONTROLLER_RST_CPU_CMPLX_CLR \
 	(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x344)
+#define CLK_RST_CONTROLLER_CLK_CPU_CMPLX_CLR \
+	(IO_ADDRESS(TEGRA_CLK_RESET_BASE) + 0x34c)
 
 #define CPU_CLOCK(cpu)	(0x1<<(8+cpu))
 #define CPU_RESET(cpu)	(0x1111ul<<(cpu))
@@ -73,11 +77,54 @@  static int tegra20_power_up_cpu(unsigned int cpu)
 	return 0;
 }
 
+static int tegra30_power_up_cpu(unsigned int cpu)
+{
+	u32 reg;
+	int ret, pwrgateid;
+	unsigned long timeout;
+
+	pwrgateid = tegra_cpu_powergate_id(cpu);
+	if (pwrgateid < 0)
+		return pwrgateid;
+
+	/* If this is the first boot, toggle powergates directly. */
+	if (!tegra_powergate_is_powered(pwrgateid)) {
+		ret = tegra_powergate_power_on(pwrgateid);
+		if (ret)
+			return ret;
+
+		/* Wait for the power to come up. */
+		timeout = jiffies + 10*HZ;
+		do {
+			if (tegra_powergate_is_powered(pwrgateid))
+				goto remove_clamps;
+			udelay(10);
+		} while (time_before(jiffies, timeout));
+		return -ETIMEDOUT;
+	}
+
+remove_clamps:
+	/* CPU partition is powered. Enable the CPU clock. */
+	writel(CPU_CLOCK(cpu), CLK_RST_CONTROLLER_CLK_CPU_CMPLX_CLR);
+	reg = readl(CLK_RST_CONTROLLER_CLK_CPU_CMPLX_CLR);
+	udelay(10);
+
+	/* Remove I/O clamps. */
+	ret = tegra_powergate_remove_clamping(pwrgateid);
+	udelay(10);
+
+	/* 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
+	/*
+	 * 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
@@ -98,6 +145,9 @@  int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
 	case TEGRA20:
 		status = tegra20_power_up_cpu(cpu);
 		break;
+	case TEGRA30:
+		status = tegra30_power_up_cpu(cpu);
+		break;
 	default:
 		status = -EINVAL;
 		break;