[RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
From: Jason Yan <yanaijie@huawei.com>
Date: 2019-07-17 07:49:38
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Add a new helper reloc_kernel_entry() to jump back to the start of the new kernel. After we put the new kernel in a randomized place we can use this new helper to enter the kernel and begin to relocate again. Signed-off-by: Jason Yan <yanaijie@huawei.com> Cc: Diana Craciun <redacted> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Christophe Leroy <redacted> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Kees Cook <redacted> --- arch/powerpc/kernel/head_fsl_booke.S | 16 ++++++++++++++++ arch/powerpc/mm/mmu_decl.h | 1 + 2 files changed, 17 insertions(+)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index a57d44638031..ce40f96dae20 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S@@ -1144,6 +1144,22 @@ _GLOBAL(create_tlb_entry) sync 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 + li r8,(MSR_IS | MSR_DS) + andc r7,r7,r8 + + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r7 + isync + sync + rfi + /* * Create a tlb entry with the same effective and physical address as * the tlb entry used by the current running code. But set the TS to 1.
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index d7737cf97cee..dae8e9177574 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h@@ -143,6 +143,7 @@ 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); extern void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry); +extern void reloc_kernel_entry(void *fdt, int addr); #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx);
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2.17.2