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-rw-r--r--arch/arm/mach-tegra/reset-handler.S239
1 files changed, 239 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
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+/*
+ * Copyright (c) 2012, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include <asm/cache.h>
+#include <asm/asm-offsets.h>
+#include <asm/hardware/cache-l2x0.h>
+
+#include "flowctrl.h"
+#include "iomap.h"
+#include "reset.h"
+#include "sleep.h"
+
+#define APB_MISC_GP_HIDREV 0x804
+#define PMC_SCRATCH41 0x140
+
+#define RESET_DATA(x) ((TEGRA_RESET_##x)*4)
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * tegra_resume
+ *
+ * CPU boot vector when restarting the a CPU following
+ * an LP2 transition. Also branched to by LP0 and LP1 resume after
+ * re-enabling sdram.
+ */
+ENTRY(tegra_resume)
+ bl v7_invalidate_l1
+ /* Enable coresight */
+ mov32 r0, 0xC5ACCE55
+ mcr p14, 0, r0, c7, c12, 6
+
+ cpu_id r0
+ cmp r0, #0 @ CPU0?
+ bne cpu_resume @ no
+
+#ifdef CONFIG_ARCH_TEGRA_3x_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)
+ beq 1f @ Yes
+ /* Clear the flow controller flags for this CPU. */
+ mov32 r2, TEGRA_FLOW_CTRL_BASE + FLOW_CTRL_CPU0_CSR @ CPU0 CSR
+ ldr r1, [r2]
+ /* Clear event & intr flag */
+ orr r1, r1, \
+ #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
+ movw r0, #0x0FFD @ enable, cluster_switch, immed, & bitmaps
+ bic r1, r1, r0
+ str r1, [r2]
+1:
+#endif
+
+#ifdef CONFIG_HAVE_ARM_SCU
+ /* enable SCU */
+ mov32 r0, TEGRA_ARM_PERIF_BASE
+ ldr r1, [r0]
+ orr r1, r1, #1
+ str r1, [r0]
+#endif
+
+ /* L2 cache resume & re-enable */
+ l2_cache_resume r0, r1, r2, l2x0_saved_regs_addr
+
+ b cpu_resume
+ENDPROC(tegra_resume)
+#endif
+
+#ifdef CONFIG_CACHE_L2X0
+ .globl l2x0_saved_regs_addr
+l2x0_saved_regs_addr:
+ .long 0
+#endif
+
+ .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
+
+ /* Waking up from LP2? */
+ ldr r9, [r12, #RESET_DATA(MASK_LP2)]
+ tst r9, r11 @ if in_lp2
+ beq __is_not_lp2
+ ldr lr, [r12, #RESET_DATA(STARTUP_LP2)]
+ cmp lr, #0
+ bleq __die @ no LP2 startup handler
+ bx lr
+
+__is_not_lp2:
+
+#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:
+#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)
+
+ .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)