---

yaml
---
r: 114521
b: refs/heads/master
c: 549e815
h: refs/heads/master
i:
  114519: 4d883e3
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e31aa453bbc4886a7bd33e5c2afa526d6f55bd7a
+refs/heads/master: 549e8152de8039506f69c677a4546e5427aa6ae7

trunk/arch/powerpc/Kconfig

@@ -806,6 +806,19 @@ config PIN_TLB
 endmenu
 
 if PPC64
+config RELOCATABLE
+	bool "Build a relocatable kernel"
+	help
+	  This builds a kernel image that is capable of running anywhere
+	  in the RMA (real memory area) at any 16k-aligned base address.
+	  The kernel is linked as a position-independent executable (PIE)
+	  and contains dynamic relocations which are processed early
+	  in the bootup process.
+
+	  One use is for the kexec on panic case where the recovery kernel
+	  must live at a different physical address than the primary
+	  kernel.
+
 config PAGE_OFFSET
 	hex
 	default "0xc000000000000000"

trunk/arch/powerpc/Makefile

@@ -63,7 +63,9 @@ override CC	+= -m$(CONFIG_WORD_SIZE)
 override AR	:= GNUTARGET=elf$(CONFIG_WORD_SIZE)-powerpc $(AR)
 endif
 
-LDFLAGS_vmlinux	:= -Bstatic
+LDFLAGS_vmlinux-yy := -Bstatic
+LDFLAGS_vmlinux-$(CONFIG_PPC64)$(CONFIG_RELOCATABLE) := -pie
+LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-yy)
 
 CFLAGS-$(CONFIG_PPC64)	:= -mminimal-toc -mtraceback=none  -mcall-aixdesc
 CFLAGS-$(CONFIG_PPC32)	:= -ffixed-r2 -mmultiple

trunk/arch/powerpc/boot/Makefile

@@ -310,8 +310,11 @@ $(obj)/dtbImage.%: vmlinux $(wrapperbits) $(obj)/%.dtb
 $(obj)/vmlinux.strip: vmlinux
 	$(STRIP) -s -R .comment $< -o $@
 
+# The iseries hypervisor won't take an ET_DYN executable, so this
+# changes the type (byte 17) in the file to ET_EXEC (2).
 $(obj)/zImage.iseries: vmlinux
 	$(STRIP) -s -R .comment $< -o $@
+	printf "\x02" | dd of=$@ conv=notrunc bs=1 seek=17
 
 $(obj)/uImage: vmlinux $(wrapperbits)
 	$(call if_changed,wrap,uboot)

trunk/arch/powerpc/boot/elf_util.c

@@ -27,7 +27,8 @@ int parse_elf64(void *hdr, struct elf_info *info)
 	      elf64->e_ident[EI_MAG3]  == ELFMAG3	&&
 	      elf64->e_ident[EI_CLASS] == ELFCLASS64	&&
 	      elf64->e_ident[EI_DATA]  == ELFDATA2MSB	&&
-	      elf64->e_type            == ET_EXEC	&&
+	      (elf64->e_type            == ET_EXEC ||
+	       elf64->e_type            == ET_DYN)	&&
 	      elf64->e_machine         == EM_PPC64))
 		return 0;
 
@@ -58,7 +59,8 @@ int parse_elf32(void *hdr, struct elf_info *info)
 	      elf32->e_ident[EI_MAG3]  == ELFMAG3	&&
 	      elf32->e_ident[EI_CLASS] == ELFCLASS32	&&
 	      elf32->e_ident[EI_DATA]  == ELFDATA2MSB	&&
-	      elf32->e_type            == ET_EXEC	&&
+	      (elf32->e_type            == ET_EXEC ||
+	       elf32->e_type            == ET_DYN)      &&
 	      elf32->e_machine         == EM_PPC))
 		return 0;
 

trunk/arch/powerpc/include/asm/mmu-hash64.h

@@ -437,7 +437,7 @@ typedef struct {
 	})
 #endif /* 1 */
 
-/* This is only valid for addresses >= KERNELBASE */
+/* This is only valid for addresses >= PAGE_OFFSET */
 static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
 {
 	if (ssize == MMU_SEGSIZE_256M)

trunk/arch/powerpc/include/asm/page.h

@@ -71,15 +71,21 @@
 #define PAGE_OFFSET	ASM_CONST(CONFIG_PAGE_OFFSET)
 #define LOAD_OFFSET	ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
 
-#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_FLATMEM)
+#if defined(CONFIG_RELOCATABLE)
 #ifndef __ASSEMBLY__
 extern phys_addr_t memstart_addr;
 extern phys_addr_t kernstart_addr;
 #endif
 #define PHYSICAL_START	kernstart_addr
-#define MEMORY_START	memstart_addr
 #else
 #define PHYSICAL_START	ASM_CONST(CONFIG_PHYSICAL_START)
+#endif
+
+#ifdef CONFIG_PPC64
+#define MEMORY_START	0UL
+#elif defined(CONFIG_RELOCATABLE)
+#define MEMORY_START	memstart_addr
+#else
 #define MEMORY_START	(PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
 #endif
 
@@ -92,8 +98,8 @@ extern phys_addr_t kernstart_addr;
 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 
-#define __va(x) ((void *)((unsigned long)(x) - PHYSICAL_START + KERNELBASE))
-#define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
+#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
+#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
 
 /*
  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,

trunk/arch/powerpc/include/asm/sections.h

@@ -16,6 +16,12 @@ static inline int in_kernel_text(unsigned long addr)
 	return 0;
 }
 
+static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
+{
+	return start < (unsigned long)__init_end &&
+		(unsigned long)_stext < end;
+}
+
 #undef dereference_function_descriptor
 void *dereference_function_descriptor(void *);
 

trunk/arch/powerpc/kernel/Makefile

@@ -35,6 +35,7 @@ obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o \
 				   paca.o cpu_setup_ppc970.o \
 				   cpu_setup_pa6t.o \
 				   firmware.o nvram_64.o
+obj64-$(CONFIG_RELOCATABLE)	+= reloc_64.o
 obj-$(CONFIG_PPC64)		+= vdso64/
 obj-$(CONFIG_ALTIVEC)		+= vecemu.o vector.o
 obj-$(CONFIG_PPC_970_NAP)	+= idle_power4.o

trunk/arch/powerpc/kernel/head_64.S

@@ -1360,6 +1360,12 @@ _INIT_STATIC(__boot_from_prom)
 	 */
 	rldicr	r1,r1,0,59
 
+#ifdef CONFIG_RELOCATABLE
+	/* Relocate code for where we are now */
+	mr	r3,r26
+	bl	.relocate
+#endif
+
 	/* Restore parameters */
 	mr	r3,r31
 	mr	r4,r30
@@ -1368,11 +1374,19 @@ _INIT_STATIC(__boot_from_prom)
 	mr	r7,r27
 
 	/* Do all of the interaction with OF client interface */
+	mr	r8,r26
 	bl	.prom_init
 	/* We never return */
 	trap
 
 _STATIC(__after_prom_start)
+#ifdef CONFIG_RELOCATABLE
+	/* process relocations for the final address of the kernel */
+	lis	r25,PAGE_OFFSET@highest	/* compute virtual base of kernel */
+	sldi	r25,r25,32
+	mr	r3,r25
+	bl	.relocate
+#endif
 
 /*
  * We need to run with _stext at physical address PHYSICAL_START.
@@ -1381,10 +1395,9 @@ _STATIC(__after_prom_start)
  *
  * Note: This process overwrites the OF exception vectors.
  */
-	LOAD_REG_IMMEDIATE(r3, PHYSICAL_START)	/* target addr */
-	cmpd	r3,r26			/* In some cases the loader may  */
+	li	r3,0			/* target addr */
+	mr.	r4,r26			/* In some cases the loader may  */
 	beq	9f			/* have already put us at zero */
-	mr	r4,r26			/* source address */
 	lis	r5,(copy_to_here - _stext)@ha
 	addi	r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
 	li	r6,0x100		/* Start offset, the first 0x100 */
@@ -1617,6 +1630,13 @@ _INIT_STATIC(start_here_multiplatform)
 	ori	r6,r6,MSR_RI
 	mtmsrd	r6			/* RI on */
 
+#ifdef CONFIG_RELOCATABLE
+	/* Save the physical address we're running at in kernstart_addr */
+	LOAD_REG_ADDR(r4, kernstart_addr)
+	clrldi	r0,r25,2
+	std	r0,0(r4)
+#endif
+
 	/* The following gets the stack set up with the regs */
 	/* pointing to the real addr of the kernel stack.  This is   */
 	/* all done to support the C function call below which sets  */

trunk/arch/powerpc/kernel/paca.c

@@ -12,6 +12,7 @@
 
 #include <asm/lppaca.h>
 #include <asm/paca.h>
+#include <asm/sections.h>
 
 /* This symbol is provided by the linker - let it fill in the paca
  * field correctly */
@@ -79,7 +80,7 @@ void __init initialise_pacas(void)
 		new_paca->lock_token = 0x8000;
 		new_paca->paca_index = cpu;
 		new_paca->kernel_toc = kernel_toc;
-		new_paca->kernelbase = KERNELBASE;
+		new_paca->kernelbase = (unsigned long) _stext;
 		new_paca->kernel_msr = MSR_KERNEL;
 		new_paca->hw_cpu_id = 0xffff;
 		new_paca->slb_shadow_ptr = &slb_shadow[cpu];

trunk/arch/powerpc/kernel/prom.c

@@ -1192,6 +1192,9 @@ void __init early_init_devtree(void *params)
 
 	/* Reserve LMB regions used by kernel, initrd, dt, etc... */
 	lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
+	/* If relocatable, reserve first 32k for interrupt vectors etc. */
+	if (PHYSICAL_START > MEMORY_START)
+		lmb_reserve(MEMORY_START, 0x8000);
 	reserve_kdump_trampoline();
 	reserve_crashkernel();
 	early_reserve_mem();

trunk/arch/powerpc/kernel/prom_init.c

@@ -2309,13 +2309,14 @@ static void __init prom_check_initrd(unsigned long r3, unsigned long r4)
 
 unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 			       unsigned long pp,
-			       unsigned long r6, unsigned long r7)
+			       unsigned long r6, unsigned long r7,
+			       unsigned long kbase)
 {	
 	struct prom_t *_prom;
 	unsigned long hdr;
-	unsigned long offset = reloc_offset();
 
 #ifdef CONFIG_PPC32
+	unsigned long offset = reloc_offset();
 	reloc_got2(offset);
 #endif
 
@@ -2349,9 +2350,11 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	 */
 	RELOC(of_platform) = prom_find_machine_type();
 
+#ifndef CONFIG_RELOCATABLE
 	/* Bail if this is a kdump kernel. */
 	if (PHYSICAL_START > 0)
 		prom_panic("Error: You can't boot a kdump kernel from OF!\n");
+#endif
 
 	/*
 	 * Check for an initrd
@@ -2371,7 +2374,7 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	 * Copy the CPU hold code
 	 */
 	if (RELOC(of_platform) != PLATFORM_POWERMAC)
-		copy_and_flush(0, KERNELBASE + offset, 0x100, 0);
+		copy_and_flush(0, kbase, 0x100, 0);
 
 	/*
 	 * Do early parsing of command line
@@ -2474,7 +2477,7 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	reloc_got2(-offset);
 #endif
 
-	__start(hdr, KERNELBASE + offset, 0);
+	__start(hdr, kbase, 0);
 
 	return 0;
 }

trunk/arch/powerpc/kernel/reloc_64.S

@@ -0,0 +1,87 @@
+/*
+ * Code to process dynamic relocations in the kernel.
+ *
+ * Copyright 2008 Paul Mackerras, IBM Corp.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/ppc_asm.h>
+
+RELA = 7
+RELACOUNT = 0x6ffffff9
+R_PPC64_RELATIVE = 22
+
+/*
+ * r3 = desired final address of kernel
+ */
+_GLOBAL(relocate)
+	mflr	r0
+	bcl	20,31,$+4
+0:	mflr	r12		/* r12 has runtime addr of label 0 */
+	mtlr	r0
+	ld	r11,(p_dyn - 0b)(r12)
+	add	r11,r11,r12	/* r11 has runtime addr of .dynamic section */
+	ld	r9,(p_rela - 0b)(r12)
+	add	r9,r9,r12	/* r9 has runtime addr of .rela.dyn section */
+	ld	r10,(p_st - 0b)(r12)
+	add	r10,r10,r12	/* r10 has runtime addr of _stext */
+
+	/*
+	 * Scan the dynamic section for the RELA and RELACOUNT entries.
+	 */
+	li	r7,0
+	li	r8,0
+1:	ld	r6,0(r11)	/* get tag */
+	cmpdi	r6,0
+	beq	4f		/* end of list */
+	cmpdi	r6,RELA
+	bne	2f
+	ld	r7,8(r11)	/* get RELA pointer in r7 */
+	b	3f
+2:	addis	r6,r6,(-RELACOUNT)@ha
+	cmpdi	r6,RELACOUNT@l
+	bne	3f
+	ld	r8,8(r11)	/* get RELACOUNT value in r8 */
+3:	addi	r11,r11,16
+	b	1b
+4:	cmpdi	r7,0		/* check we have both RELA and RELACOUNT */
+	cmpdi	cr1,r8,0
+	beq	6f
+	beq	cr1,6f
+
+	/*
+	 * Work out linktime address of _stext and hence the
+	 * relocation offset to be applied.
+	 * cur_offset [r7] = rela.run [r9] - rela.link [r7]
+	 * _stext.link [r10] = _stext.run [r10] - cur_offset [r7]
+	 * final_offset [r3] = _stext.final [r3] - _stext.link [r10]
+	 */
+	subf	r7,r7,r9	/* cur_offset */
+	subf	r10,r7,r10
+	subf	r3,r10,r3	/* final_offset */
+
+	/*
+	 * Run through the list of relocations and process the
+	 * R_PPC64_RELATIVE ones.
+	 */
+	mtctr	r8
+5:	lwz	r0,12(9)	/* ELF64_R_TYPE(reloc->r_info) */
+	cmpwi	r0,R_PPC64_RELATIVE
+	bne	6f
+	ld	r6,0(r9)	/* reloc->r_offset */
+	ld	r0,16(r9)	/* reloc->r_addend */
+	add	r0,r0,r3
+	stdx	r0,r7,r6
+	addi	r9,r9,24
+	bdnz	5b
+
+6:	blr
+
+p_dyn:	.llong	__dynamic_start - 0b
+p_rela:	.llong	__rela_dyn_start - 0b
+p_st:	.llong	_stext - 0b
+

trunk/arch/powerpc/kernel/vmlinux.lds.S

@@ -187,6 +187,21 @@ SECTIONS
 		*(.machine.desc)
 		__machine_desc_end = . ;
 	}
+	. = ALIGN(8);
+	.dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) { *(.dynsym) }
+	.dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) }
+	.dynamic : AT(ADDR(.dynamic) - LOAD_OFFSET)
+	{
+		__dynamic_start = .;
+		*(.dynamic)
+	}
+	.hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) }
+	.interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) }
+	.rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET)
+	{
+		__rela_dyn_start = .;
+		*(.rela*)
+	}
 
 	/* freed after init ends here */
 	. = ALIGN(PAGE_SIZE);

trunk/arch/powerpc/mm/hash_utils_64.c

@@ -194,7 +194,7 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 		unsigned long tprot = prot;
 
 		/* Make kernel text executable */
-		if (in_kernel_text(vaddr))
+		if (overlaps_kernel_text(vaddr, vaddr + step))
 			tprot &= ~HPTE_R_N;
 
 		hash = hpt_hash(va, shift, ssize);