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>

2 files changed, 62 insertions, 43 deletions

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)