[PATCH 04/14] powerpc: Make load_hander handle upto 64k offset
From: Michael Neuling <hidden>
Date: 2012-11-09 06:19:02
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
If we change load_hander() to use an ori instead of addi, we can load handlers upto 64k away provided we are still 64k aligned. --- arch/powerpc/include/asm/exception-64s.h | 3 ++- arch/powerpc/kernel/exceptions-64s.S | 4 ++-- arch/powerpc/kernel/setup_64.c | 5 +++++ 3 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index a43c147..9258daa 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h@@ -55,7 +55,8 @@ * word. */ #define LOAD_HANDLER(reg, label) \ - addi reg,reg,(label)-_stext; /* virt addr of handler ... */ + /* Handlers must be within 64K of kbase, which must be 64k aligned */ \ + ori reg,reg,(label)-_stext; /* virt addr of handler ... */ /* Exception register prefixes */ #define EXC_HV H
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index de02964..0969b7f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S@@ -585,8 +585,8 @@ __end_interrupts: * Code from here down to __end_handlers is invoked from the * exception prologs above. Because the prologs assemble the * addresses of these handlers using the LOAD_HANDLER macro, - * which uses an addi instruction, these handlers must be in - * the first 32k of the kernel image. + * which uses an ori instruction, these handlers must be in + * the first 64k of the kernel image. */ /*** Common interrupt handlers ***/
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index efb6a41..6da881b 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c@@ -601,6 +601,11 @@ void __init setup_arch(char **cmdline_p) kvm_linear_init(); + /* Interrupt code needs to be 64K-aligned */ + if ((unsigned long)_stext & 0xffff) + panic("Kernelbase not 64K-aligned (0x%lx)!\n", + (unsigned long)_stext); + ppc64_boot_msg(0x15, "Setup Done"); }
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1.7.9.5