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-rw-r--r--arch/arm/common/mcpm_head.S86
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
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+/*
+ * arch/arm/common/mcpm_head.S -- kernel entry point for multi-cluster PM
+ *
+ * Created by: Nicolas Pitre, March 2012
+ * Copyright: (C) 2012-2013 Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/mcpm.h>
+
+ .macro pr_dbg string
+#if defined(CONFIG_DEBUG_LL) && defined(DEBUG)
+ b 1901f
+1902: .asciz "CPU"
+1903: .asciz " cluster"
+1904: .asciz ": \string"
+ .align
+1901: adr r0, 1902b
+ bl printascii
+ mov r0, r9
+ bl printhex8
+ adr r0, 1903b
+ bl printascii
+ mov r0, r10
+ bl printhex8
+ adr r0, 1904b
+ bl printascii
+#endif
+ .endm
+
+ .arm
+ .align
+
+ENTRY(mcpm_entry_point)
+
+ THUMB( adr r12, BSYM(1f) )
+ THUMB( bx r12 )
+ THUMB( .thumb )
+1:
+ mrc p15, 0, r0, c0, c0, 5 @ MPIDR
+ ubfx r9, r0, #0, #8 @ r9 = cpu
+ ubfx r10, r0, #8, #8 @ r10 = cluster
+ mov r3, #MAX_CPUS_PER_CLUSTER
+ mla r4, r3, r10, r9 @ r4 = canonical CPU index
+ cmp r4, #(MAX_CPUS_PER_CLUSTER * MAX_NR_CLUSTERS)
+ blo 2f
+
+ /* We didn't expect this CPU. Try to cheaply make it quiet. */
+1: wfi
+ wfe
+ b 1b
+
+2: pr_dbg "kernel mcpm_entry_point\n"
+
+ /*
+ * MMU is off so we need to get to mcpm_entry_vectors in a
+ * position independent way.
+ */
+ adr r5, 3f
+ ldr r6, [r5]
+ add r6, r5, r6 @ r6 = mcpm_entry_vectors
+
+mcpm_entry_gated:
+ ldr r5, [r6, r4, lsl #2] @ r5 = CPU entry vector
+ cmp r5, #0
+ wfeeq
+ beq mcpm_entry_gated
+ pr_dbg "released\n"
+ bx r5
+
+ .align 2
+
+3: .word mcpm_entry_vectors - .
+
+ENDPROC(mcpm_entry_point)
+
+ .bss
+ .align 5
+
+ .type mcpm_entry_vectors, #object
+ENTRY(mcpm_entry_vectors)
+ .space 4 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER