From 5085f3ff458521045f7e43da62b8c30ea7df2e82 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 1 Oct 2010 15:37:05 +0100
Subject: ARM: hotplug cpu: Keep processor information, startup code &
 __lookup_processor_type

When hotplug CPU is enabled, we need to keep the list of supported CPUs,
their setup functions, and __lookup_processor_type in place so that we
can find and initialize secondary CPUs.  Move these into the __CPUINIT
section.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/kernel/head-common.S | 81 ++++++++++++++++++++++++-------------------
 arch/arm/kernel/vmlinux.lds.S | 24 +++++++++----
 2 files changed, 62 insertions(+), 43 deletions(-)

(limited to 'arch/arm/kernel')

diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index b9505aa267c0..6ad24d2cb14b 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -145,45 +145,14 @@ ENDPROC(__error)
 
 
 /*
- * Read processor ID register (CP#15, CR0), and look up in the linker-built
- * supported processor list.  Note that we can't use the absolute addresses
- * for the __proc_info lists since we aren't running with the MMU on
- * (and therefore, we are not in the correct address space).  We have to
- * calculate the offset.
- *
- *	r9 = cpuid
- * Returns:
- *	r3, r4, r6 corrupted
- *	r5 = proc_info pointer in physical address space
- *	r9 = cpuid (preserved)
- */
-__lookup_processor_type:
-	adr	r3, 3f
-	ldmia	r3, {r5 - r7}
-	add	r3, r3, #8
-	sub	r3, r3, r7			@ get offset between virt&phys
-	add	r5, r5, r3			@ convert virt addresses to
-	add	r6, r6, r3			@ physical address space
-1:	ldmia	r5, {r3, r4}			@ value, mask
-	and	r4, r4, r9			@ mask wanted bits
-	teq	r3, r4
-	beq	2f
-	add	r5, r5, #PROC_INFO_SZ		@ sizeof(proc_info_list)
-	cmp	r5, r6
-	blo	1b
-	mov	r5, #0				@ unknown processor
-2:	mov	pc, lr
-ENDPROC(__lookup_processor_type)
-
-/*
- * This provides a C-API version of the above function.
+ * This provides a C-API version of __lookup_processor_type
  */
 ENTRY(lookup_processor_type)
-	stmfd	sp!, {r4 - r7, r9, lr}
+	stmfd	sp!, {r4 - r6, r9, lr}
 	mov	r9, r0
 	bl	__lookup_processor_type
 	mov	r0, r5
-	ldmfd	sp!, {r4 - r7, r9, pc}
+	ldmfd	sp!, {r4 - r6, r9, pc}
 ENDPROC(lookup_processor_type)
 
 /*
@@ -191,8 +160,6 @@ ENDPROC(lookup_processor_type)
  * more information about the __proc_info and __arch_info structures.
  */
 	.align	2
-3:	.long	__proc_info_begin
-	.long	__proc_info_end
 4:	.long	.
 	.long	__arch_info_begin
 	.long	__arch_info_end
@@ -265,3 +232,45 @@ __vet_atags:
 1:	mov	r2, #0
 	mov	pc, lr
 ENDPROC(__vet_atags)
+
+/*
+ * Read processor ID register (CP#15, CR0), and look up in the linker-built
+ * supported processor list.  Note that we can't use the absolute addresses
+ * for the __proc_info lists since we aren't running with the MMU on
+ * (and therefore, we are not in the correct address space).  We have to
+ * calculate the offset.
+ *
+ *	r9 = cpuid
+ * Returns:
+ *	r3, r4, r6 corrupted
+ *	r5 = proc_info pointer in physical address space
+ *	r9 = cpuid (preserved)
+ */
+	__CPUINIT
+__lookup_processor_type:
+	adr	r3, __lookup_processor_type_data
+	ldmia	r3, {r4 - r6}
+	sub	r3, r3, r4			@ get offset between virt&phys
+	add	r5, r5, r3			@ convert virt addresses to
+	add	r6, r6, r3			@ physical address space
+1:	ldmia	r5, {r3, r4}			@ value, mask
+	and	r4, r4, r9			@ mask wanted bits
+	teq	r3, r4
+	beq	2f
+	add	r5, r5, #PROC_INFO_SZ		@ sizeof(proc_info_list)
+	cmp	r5, r6
+	blo	1b
+	mov	r5, #0				@ unknown processor
+2:	mov	pc, lr
+ENDPROC(__lookup_processor_type)
+
+/*
+ * Look in <asm/procinfo.h> for information about the __proc_info structure.
+ */
+	.align	2
+	.type	__lookup_processor_type_data, %object
+__lookup_processor_type_data:
+	.long	.
+	.long	__proc_info_begin
+	.long	__proc_info_end
+	.size	__lookup_processor_type_data, . - __lookup_processor_type_data
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index b16c07914b55..1630524a3097 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -8,6 +8,19 @@
 #include <asm/memory.h>
 #include <asm/page.h>
 	
+#define PROC_INFO							\
+	VMLINUX_SYMBOL(__proc_info_begin) = .;				\
+	*(.proc.info.init)						\
+	VMLINUX_SYMBOL(__proc_info_end) = .;
+
+#ifdef CONFIG_HOTPLUG_CPU
+#define ARM_CPU_DISCARD(x)
+#define ARM_CPU_KEEP(x)		x
+#else
+#define ARM_CPU_DISCARD(x)	x
+#define ARM_CPU_KEEP(x)
+#endif
+
 OUTPUT_ARCH(arm)
 ENTRY(stext)
 
@@ -31,9 +44,7 @@ SECTIONS
 			HEAD_TEXT
 			INIT_TEXT
 		_einittext = .;
-		__proc_info_begin = .;
-			*(.proc.info.init)
-		__proc_info_end = .;
+		ARM_CPU_DISCARD(PROC_INFO)
 		__arch_info_begin = .;
 			*(.arch.info.init)
 		__arch_info_end = .;
@@ -68,10 +79,8 @@ SECTIONS
 	/DISCARD/ : {
 		*(.ARM.exidx.exit.text)
 		*(.ARM.extab.exit.text)
-#ifndef CONFIG_HOTPLUG_CPU
-		*(.ARM.exidx.cpuexit.text)
-		*(.ARM.extab.cpuexit.text)
-#endif
+		ARM_CPU_DISCARD(*(.ARM.exidx.cpuexit.text))
+		ARM_CPU_DISCARD(*(.ARM.extab.cpuexit.text))
 #ifndef CONFIG_HOTPLUG
 		*(.ARM.exidx.devexit.text)
 		*(.ARM.extab.devexit.text)
@@ -100,6 +109,7 @@ SECTIONS
 			*(.glue_7)
 			*(.glue_7t)
 		*(.got)			/* Global offset table		*/
+			ARM_CPU_KEEP(PROC_INFO)
 	}
 
 	RO_DATA(PAGE_SIZE)
-- 
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