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>
diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S
index b5349b2..37d6dd9 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 @@
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)