ARM: tegra: rework Tegra secondary CPU core bringup

Prepare the Tegra secondary CPU core bringup code for other Tegra variants.
The reset handler is also generalized to allow for future introduction of
powersaving modes which turn off the CPU cores.

Based on work by:

Scott Williams <scwilliams@nvidia.com>
Chris Johnson <cwj@nvidia.com>
Colin Cross <ccross@android.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 127 insertions, 8 deletions

diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S
index b5349b2f13d2..37d6dd96d62f 100644
--- a/arch/arm/mach-tegra/headsmp.S
+++ b/arch/arm/mach-tegra/headsmp.S
@@ -1,6 +1,23 @@
 #include <linux/linkage.h>
 #include <linux/init.h>
 
+#include <asm/cache.h>
+
+#include <mach/iomap.h>
+
+#include "flowctrl.h"
+#include "reset.h"
+
+#define APB_MISC_GP_HIDREV	0x804
+#define PMC_SCRATCH41	0x140
+
+#define RESET_DATA(x)	((TEGRA_RESET_##x)*4)
+
+	.macro mov32, reg, val
+	movw	\reg, #:lower16:\val
+	movt	\reg, #:upper16:\val
+	.endm
+
         .section ".text.head", "ax"
 	__CPUINIT
 
@@ -47,15 +64,117 @@ ENTRY(v7_invalidate_l1)
         mov     pc, lr
 ENDPROC(v7_invalidate_l1)
 
+
 ENTRY(tegra_secondary_startup)
-	msr	cpsr_fsxc, #0xd3
         bl      v7_invalidate_l1
-	mrc	p15, 0, r0, c0, c0, 5
-        and	r0, r0, #15
-        ldr     r1, =0x6000f100
-        str     r0, [r1]
-1:      ldr     r2, [r1]
-        cmp     r0, r2
-        beq     1b
+	/* Enable coresight */
+	mov32	r0, 0xC5ACCE55
+	mcr	p14, 0, r0, c7, c12, 6
         b       secondary_startup
 ENDPROC(tegra_secondary_startup)
+
+	.align L1_CACHE_SHIFT
+ENTRY(__tegra_cpu_reset_handler_start)
+
+/*
+ * __tegra_cpu_reset_handler:
+ *
+ * Common handler for all CPU reset events.
+ *
+ * Register usage within the reset handler:
+ *
+ *      R7  = CPU present (to the OS) mask
+ *      R8  = CPU in LP1 state mask
+ *      R9  = CPU in LP2 state mask
+ *      R10 = CPU number
+ *      R11 = CPU mask
+ *      R12 = pointer to reset handler data
+ *
+ * NOTE: This code is copied to IRAM. All code and data accesses
+ *       must be position-independent.
+ */
+
+	.align L1_CACHE_SHIFT
+ENTRY(__tegra_cpu_reset_handler)
+
+	cpsid	aif, 0x13			@ SVC mode, interrupts disabled
+	mrc	p15, 0, r10, c0, c0, 5		@ MPIDR
+	and	r10, r10, #0x3			@ R10 = CPU number
+	mov	r11, #1
+	mov	r11, r11, lsl r10  		@ R11 = CPU mask
+	adr	r12, __tegra_cpu_reset_handler_data
+
+#ifdef CONFIG_SMP
+	/* Does the OS know about this CPU? */
+	ldr	r7, [r12, #RESET_DATA(MASK_PRESENT)]
+	tst	r7, r11 			@ if !present
+	bleq	__die				@ CPU not present (to OS)
+#endif
+
+#ifdef CONFIG_ARCH_TEGRA_2x_SOC
+	/* Are we on Tegra20? */
+	mov32	r6, TEGRA_APB_MISC_BASE
+	ldr	r0, [r6, #APB_MISC_GP_HIDREV]
+	and	r0, r0, #0xff00
+	cmp	r0, #(0x20 << 8)
+	bne	1f
+	/* If not CPU0, don't let CPU0 reset CPU1 now that CPU1 is coming up. */
+	mov32	r6, TEGRA_PMC_BASE
+	mov	r0, #0
+	cmp	r10, #0
+	strne	r0, [r6, #PMC_SCRATCH41]
+1:
+#endif
+
+#ifdef CONFIG_SMP
+	/*
+	 * Can only be secondary boot (initial or hotplug) but CPU 0
+	 * cannot be here.
+	 */
+	cmp	r10, #0
+	bleq	__die				@ CPU0 cannot be here
+	ldr	lr, [r12, #RESET_DATA(STARTUP_SECONDARY)]
+	cmp	lr, #0
+	bleq	__die				@ no secondary startup handler
+	bx	lr
+#endif
+
+/*
+ * We don't know why the CPU reset. Just kill it.
+ * The LR register will contain the address we died at + 4.
+ */
+
+__die:
+	sub	lr, lr, #4
+	mov32	r7, TEGRA_PMC_BASE
+	str	lr, [r7, #PMC_SCRATCH41]
+
+	mov32	r7, TEGRA_CLK_RESET_BASE
+
+	/* Are we on Tegra20? */
+	mov32	r6, TEGRA_APB_MISC_BASE
+	ldr	r0, [r6, #APB_MISC_GP_HIDREV]
+	and	r0, r0, #0xff00
+	cmp	r0, #(0x20 << 8)
+	bne	1f
+
+#ifdef CONFIG_ARCH_TEGRA_2x_SOC
+	mov32	r0, 0x1111
+	mov	r1, r0, lsl r10
+	str	r1, [r7, #0x340]		@ CLK_RST_CPU_CMPLX_SET
+#endif
+1:
+	/* If the CPU still isn't dead, just spin here. */
+	b	.
+ENDPROC(__tegra_cpu_reset_handler)
+
+	.align L1_CACHE_SHIFT
+	.type	__tegra_cpu_reset_handler_data, %object
+	.globl	__tegra_cpu_reset_handler_data
+__tegra_cpu_reset_handler_data:
+	.rept	TEGRA_RESET_DATA_SIZE
+	.long	0
+	.endr
+	.align L1_CACHE_SHIFT
+
+ENTRY(__tegra_cpu_reset_handler_end)