4 files changed, 65 insertions, 1 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f0a893142cee..4bb52e6488ea 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -884,7 +884,7 @@ config DYNAMIC_MEMSTART
 
 config RELOCATABLE
         bool "Build a relocatable kernel"
-        depends on ADVANCED_OPTIONS && FLATMEM && 44x
+        depends on ADVANCED_OPTIONS && FLATMEM && (44x || FSL_BOOKE)
         select NONSTATIC_KERNEL
         help
           This builds a kernel image that is capable of running at the
diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
index a92c79be2728..f22e7e44fbf3 100644
--- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S
+++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
@@ -176,6 +176,8 @@ skpinv:	addi	r6,r6,1				/* Increment */
 /* 7. Jump to KERNELBASE mapping */
         lis     r6,(KERNELBASE & ~0xfff)@h
         ori     r6,r6,(KERNELBASE & ~0xfff)@l
+        rlwinm  r7,r25,0,0x03ffffff
+        add     r6,r7,r6
 
 #elif defined(ENTRY_MAPPING_KEXEC_SETUP)
 /*
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 196950f29c00..19bd574bda9d 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -73,6 +73,30 @@ _ENTRY(_start);
         li      r24,0                   /* CPU number */
         li      r23,0                   /* phys kernel start (high) */
 
+#ifdef CONFIG_RELOCATABLE
+        LOAD_REG_ADDR_PIC(r3, _stext)   /* Get our current runtime base */
+
+        /* Translate _stext address to physical, save in r23/r25 */
+        bl      get_phys_addr
+        mr      r23,r3
+        mr      r25,r4
+
+        /*
+         * We have the runtime (virutal) address of our base.
+         * We calculate our shift of offset from a 64M page.
+         * We could map the 64M page we belong to at PAGE_OFFSET and
+         * get going from there.
+         */
+        lis     r4,KERNELBASE@h
+        ori     r4,r4,KERNELBASE@l
+        rlwinm  r6,r25,0,0x3ffffff              /* r6 = PHYS_START % 64M */
+        rlwinm  r5,r4,0,0x3ffffff               /* r5 = KERNELBASE % 64M */
+        subf    r3,r5,r6                        /* r3 = r6 - r5 */
+        add     r3,r4,r3                        /* Required Virtual Address */
+
+        bl      relocate
+#endif
+
 /* We try to not make any assumptions about how the boot loader
  * setup or used the TLBs.  We invalidate all mappings from the
  * boot loader and load a single entry in TLB1[0] to map the
@@ -182,6 +206,16 @@ _ENTRY(__early_start)
 
         bl      early_init
 
+#ifdef CONFIG_RELOCATABLE
+#ifdef CONFIG_PHYS_64BIT
+        mr      r3,r23
+        mr      r4,r25
+#else
+        mr      r3,r25
+#endif
+        bl      relocate_init
+#endif
+
 #ifdef CONFIG_DYNAMIC_MEMSTART
         lis     r3,kernstart_addr@ha
         la      r3,kernstart_addr@l(r3)
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 07ba45b0f07c..ce4a1163ddd3 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -241,4 +241,32 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
         /* 64M mapped initially according to head_fsl_booke.S */
         memblock_set_current_limit(min_t(u64, limit, 0x04000000));
 }
+
+#ifdef CONFIG_RELOCATABLE
+notrace void __init relocate_init(phys_addr_t start)
+{
+        unsigned long base = KERNELBASE;
+
+        /*
+         * Relocatable kernel support based on processing of dynamic
+         * relocation entries.
+         * Compute the virt_phys_offset :
+         * virt_phys_offset = stext.run - kernstart_addr
+         *
+         * stext.run = (KERNELBASE & ~0x3ffffff) + (kernstart_addr & 0x3ffffff)
+         * When we relocate, we have :
+         *
+         *      (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
+         *
+         * hence:
+         *  virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
+         *                              (kernstart_addr & ~0x3ffffff)
+         *
+         */
+        kernstart_addr = start;
+        start &= ~0x3ffffff;
+        base &= ~0x3ffffff;
+        virt_phys_offset = base - start;
+}
+#endif
 #endif