[PATCH v4 2/6] powerpc/fsl_booke/64: introduce reloc_kernel_entry() helper

[Jason Yan]

Like the 32bit code, we introduce reloc_kernel_entry() helper to prepare
for the KASLR 64bit version. And move the C declaration of this function
out of CONFIG_PPC32 and use long instead of int for the parameter 'addr'.

Signed-off-by: Jason Yan <yanaijie at huawei.com>
Cc: Scott Wood <oss at buserror.net>
Cc: Diana Craciun <diana.craciun at nxp.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy at c-s.fr>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Nicholas Piggin <npiggin at gmail.com>
Cc: Kees Cook <keescook at chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy at c-s.fr>
---
 arch/powerpc/kernel/exceptions-64e.S | 13 +++++++++++++
 arch/powerpc/mm/mmu_decl.h           |  3 ++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index e4076e3c072d..1b9b174bee86 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1679,3 +1679,16 @@ _GLOBAL(setup_ehv_ivors)
 _GLOBAL(setup_lrat_ivor)
 	SET_IVOR(42, 0x340) /* LRAT Error */
 	blr
+
+/*
+ * Return to the start of the relocated kernel and run again
+ * r3 - virtual address of fdt
+ * r4 - entry of the kernel
+ */
+_GLOBAL(reloc_kernel_entry)
+	mfmsr	r7
+	rlwinm	r7, r7, 0, ~(MSR_IS | MSR_DS)
+
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r7
+	rfi
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 7097e07a209a..605129b5ccdf 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -140,9 +140,10 @@ extern void adjust_total_lowmem(void);
 extern int switch_to_as1(void);
 extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu);
 void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys);
-void reloc_kernel_entry(void *fdt, int addr);
 extern int is_second_reloc;
 #endif
+
+void reloc_kernel_entry(void *fdt, long addr);
 extern void loadcam_entry(unsigned int index);
 extern void loadcam_multi(int first_idx, int num, int tmp_idx);
 
-- 
2.17.2