.code64
.globl startup_64
startup_64:
-
/*
* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
* and someone has loaded an identity mapped page table
* for us. These identity mapped page tables map all of the
* kernel pages and possibly all of memory.
*
- * %esi holds a physical pointer to real_mode_data.
+ * %rsi holds a physical pointer to real_mode_data.
*
* We come here either directly from a 64bit bootloader, or from
* arch/x86_64/boot/compressed/head.S.
* tables and then reload them.
*/
- /* Compute the delta between the address I am compiled to run at and the
+ /*
+ * Compute the delta between the address I am compiled to run at and the
* address I am actually running at.
*/
leaq _text(%rip), %rbp
testl %eax, %eax
jnz bad_address
- /* Is the address too large? */
- leaq _text(%rip), %rdx
- movq $PGDIR_SIZE, %rax
- cmpq %rax, %rdx
- jae bad_address
-
- /* Fixup the physical addresses in the page table
+ /*
+ * Is the address too large?
*/
- addq %rbp, init_level4_pgt + 0(%rip)
- addq %rbp, init_level4_pgt + (L4_PAGE_OFFSET*8)(%rip)
- addq %rbp, init_level4_pgt + (L4_START_KERNEL*8)(%rip)
+ leaq _text(%rip), %rax
+ shrq $MAX_PHYSMEM_BITS, %rax
+ jnz bad_address
- addq %rbp, level3_ident_pgt + 0(%rip)
+ /*
+ * Fixup the physical addresses in the page table
+ */
+ addq %rbp, early_level4_pgt + (L4_START_KERNEL*8)(%rip)
addq %rbp, level3_kernel_pgt + (510*8)(%rip)
addq %rbp, level3_kernel_pgt + (511*8)(%rip)
addq %rbp, level2_fixmap_pgt + (506*8)(%rip)
- /* Add an Identity mapping if I am above 1G */
+ /*
+ * Set up the identity mapping for the switchover. These
+ * entries should *NOT* have the global bit set! This also
+ * creates a bunch of nonsense entries but that is fine --
+ * it avoids problems around wraparound.
+ */
leaq _text(%rip), %rdi
- andq $PMD_PAGE_MASK, %rdi
+ leaq early_level4_pgt(%rip), %rbx
movq %rdi, %rax
- shrq $PUD_SHIFT, %rax
- andq $(PTRS_PER_PUD - 1), %rax
- jz ident_complete
+ shrq $PGDIR_SHIFT, %rax
- leaq (level2_spare_pgt - __START_KERNEL_map + _KERNPG_TABLE)(%rbp), %rdx
- leaq level3_ident_pgt(%rip), %rbx
- movq %rdx, 0(%rbx, %rax, 8)
+ leaq (4096 + _KERNPG_TABLE)(%rbx), %rdx
+ movq %rdx, 0(%rbx,%rax,8)
+ movq %rdx, 8(%rbx,%rax,8)
+ addq $4096, %rdx
movq %rdi, %rax
- shrq $PMD_SHIFT, %rax
- andq $(PTRS_PER_PMD - 1), %rax
- leaq __PAGE_KERNEL_IDENT_LARGE_EXEC(%rdi), %rdx
- leaq level2_spare_pgt(%rip), %rbx
- movq %rdx, 0(%rbx, %rax, 8)
-ident_complete:
+ shrq $PUD_SHIFT, %rax
+ andl $(PTRS_PER_PUD-1), %eax
+ movq %rdx, (4096+0)(%rbx,%rax,8)
+ movq %rdx, (4096+8)(%rbx,%rax,8)
+
+ addq $8192, %rbx
+ movq %rdi, %rax
+ shrq $PMD_SHIFT, %rdi
+ addq $(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL), %rax
+ leaq (_end - 1)(%rip), %rcx
+ shrq $PMD_SHIFT, %rcx
+ subq %rdi, %rcx
+ incl %ecx
+
+1:
+ andq $(PTRS_PER_PMD - 1), %rdi
+ movq %rax, (%rbx,%rdi,8)
+ incq %rdi
+ addq $PMD_SIZE, %rax
+ decl %ecx
+ jnz 1b
/*
* Fixup the kernel text+data virtual addresses. Note that
* cleanup_highmap() fixes this up along with the mappings
* beyond _end.
*/
-
leaq level2_kernel_pgt(%rip), %rdi
leaq 4096(%rdi), %r8
/* See if it is a valid page table entry */
/* Fixup phys_base */
addq %rbp, phys_base(%rip)
- /* Due to ENTRY(), sometimes the empty space gets filled with
- * zeros. Better take a jmp than relying on empty space being
- * filled with 0x90 (nop)
- */
- jmp secondary_startup_64
+ movq $(early_level4_pgt - __START_KERNEL_map), %rax
+ jmp 1f
ENTRY(secondary_startup_64)
/*
* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
* and someone has loaded a mapped page table.
*
- * %esi holds a physical pointer to real_mode_data.
+ * %rsi holds a physical pointer to real_mode_data.
*
* We come here either from startup_64 (using physical addresses)
* or from trampoline.S (using virtual addresses).
* after the boot processor executes this code.
*/
+ movq $(init_level4_pgt - __START_KERNEL_map), %rax
+1:
+
/* Enable PAE mode and PGE */
- movl $(X86_CR4_PAE | X86_CR4_PGE), %eax
- movq %rax, %cr4
+ movl $(X86_CR4_PAE | X86_CR4_PGE), %ecx
+ movq %rcx, %cr4
/* Setup early boot stage 4 level pagetables. */
- movq $(init_level4_pgt - __START_KERNEL_map), %rax
addq phys_base(%rip), %rax
movq %rax, %cr3
movq %rax, %cr0
/* Setup a boot time stack */
- movq stack_start(%rip),%rsp
+ movq stack_start(%rip), %rsp
/* zero EFLAGS after setting rsp */
pushq $0
movl initial_gs+4(%rip),%edx
wrmsr
- /* esi is pointer to real mode structure with interesting info.
+ /* rsi is pointer to real mode structure with interesting info.
pass it to C */
- movl %esi, %edi
+ movq %rsi, %rdi
/* Finally jump to run C code and to be on real kernel address
* Since we are running on identity-mapped space we have to jump
* to the full 64bit address, this is only possible as indirect
* jump. In addition we need to ensure %cs is set so we make this
* a far return.
+ *
+ * Note: do not change to far jump indirect with 64bit offset.
+ *
+ * AMD does not support far jump indirect with 64bit offset.
+ * AMD64 Architecture Programmer's Manual, Volume 3: states only
+ * JMP FAR mem16:16 FF /5 Far jump indirect,
+ * with the target specified by a far pointer in memory.
+ * JMP FAR mem16:32 FF /5 Far jump indirect,
+ * with the target specified by a far pointer in memory.
+ *
+ * Intel64 does support 64bit offset.
+ * Software Developer Manual Vol 2: states:
+ * FF /5 JMP m16:16 Jump far, absolute indirect,
+ * address given in m16:16
+ * FF /5 JMP m16:32 Jump far, absolute indirect,
+ * address given in m16:32.
+ * REX.W + FF /5 JMP m16:64 Jump far, absolute indirect,
+ * address given in m16:64.
*/
movq initial_code(%rip),%rax
pushq $0 # fake return address to stop unwinder
/* SMP bootup changes these two */
__REFDATA
- .align 8
- ENTRY(initial_code)
+ .balign 8
+ GLOBAL(initial_code)
.quad x86_64_start_kernel
- ENTRY(initial_gs)
+ GLOBAL(initial_gs)
.quad INIT_PER_CPU_VAR(irq_stack_union)
- ENTRY(stack_start)
+ GLOBAL(stack_start)
.quad init_thread_union+THREAD_SIZE-8
.word 0
__FINITDATA
bad_address:
jmp bad_address
- .section ".init.text","ax"
+ __INIT
.globl early_idt_handlers
early_idt_handlers:
# 104(%rsp) %rflags
i = i + 1
.endr
+/* This is global to keep gas from relaxing the jumps */
ENTRY(early_idt_handler)
cld
pushq %r11 # 0(%rsp)
cmpl $__KERNEL_CS,96(%rsp)
- jne 10f
+ jne 11f
+
+ cmpl $14,72(%rsp) # Page fault?
+ jnz 10f
+ GET_CR2_INTO(%rdi) # can clobber any volatile register if pv
+ call early_make_pgtable
+ andl %eax,%eax
+ jz 20f # All good
+10:
leaq 88(%rsp),%rdi # Pointer to %rip
call early_fixup_exception
andl %eax,%eax
jnz 20f # Found an exception entry
-10:
+11:
#ifdef CONFIG_EARLY_PRINTK
GET_CR2_INTO(%r9) # can clobber any volatile register if pv
movl 80(%rsp),%r8d # error code
1: hlt
jmp 1b
-20: # Exception table entry found
+20: # Exception table entry found or page table generated
popq %r11
popq %r10
popq %r9
addq $16,%rsp # drop vector number and error code
decl early_recursion_flag(%rip)
INTERRUPT_RETURN
+ENDPROC(early_idt_handler)
+
+ __INITDATA
.balign 4
early_recursion_flag:
early_idt_ripmsg:
.asciz "RIP %s\n"
#endif /* CONFIG_EARLY_PRINTK */
- .previous
#define NEXT_PAGE(name) \
.balign PAGE_SIZE; \
-ENTRY(name)
+GLOBAL(name)
/* Automate the creation of 1 to 1 mapping pmd entries */
#define PMDS(START, PERM, COUNT) \
i = i + 1 ; \
.endr
+ __INITDATA
+NEXT_PAGE(early_level4_pgt)
+ .fill 511,8,0
+ .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
+
+NEXT_PAGE(early_dynamic_pgts)
+ .fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0
+
.data
- /*
- * This default setting generates an ident mapping at address 0x100000
- * and a mapping for the kernel that precisely maps virtual address
- * 0xffffffff80000000 to physical address 0x000000. (always using
- * 2Mbyte large pages provided by PAE mode)
- */
+
+#ifndef CONFIG_XEN
NEXT_PAGE(init_level4_pgt)
- .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
- .org init_level4_pgt + L4_PAGE_OFFSET*8, 0
- .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
- .org init_level4_pgt + L4_START_KERNEL*8, 0
+ .fill 512,8,0
+#else
+NEXT_PAGE(init_level4_pgt)
+ .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
+ .org init_level4_pgt + L4_PAGE_OFFSET*8, 0
+ .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
+ .org init_level4_pgt + L4_START_KERNEL*8, 0
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
- .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
+ .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
NEXT_PAGE(level3_ident_pgt)
.quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
- .fill 511,8,0
+ .fill 511, 8, 0
+NEXT_PAGE(level2_ident_pgt)
+ /* Since I easily can, map the first 1G.
+ * Don't set NX because code runs from these pages.
+ */
+ PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
+#endif
NEXT_PAGE(level3_kernel_pgt)
.fill L3_START_KERNEL,8,0
.quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE
.quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE
-NEXT_PAGE(level2_fixmap_pgt)
- .fill 506,8,0
- .quad level1_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE
- /* 8MB reserved for vsyscalls + a 2MB hole = 4 + 1 entries */
- .fill 5,8,0
-
-NEXT_PAGE(level1_fixmap_pgt)
- .fill 512,8,0
-
-NEXT_PAGE(level2_ident_pgt)
- /* Since I easily can, map the first 1G.
- * Don't set NX because code runs from these pages.
- */
- PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
-
NEXT_PAGE(level2_kernel_pgt)
/*
* 512 MB kernel mapping. We spend a full page on this pagetable
PMDS(0, __PAGE_KERNEL_LARGE_EXEC,
KERNEL_IMAGE_SIZE/PMD_SIZE)
-NEXT_PAGE(level2_spare_pgt)
- .fill 512, 8, 0
+NEXT_PAGE(level2_fixmap_pgt)
+ .fill 506,8,0
+ .quad level1_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE
+ /* 8MB reserved for vsyscalls + a 2MB hole = 4 + 1 entries */
+ .fill 5,8,0
+
+NEXT_PAGE(level1_fixmap_pgt)
+ .fill 512,8,0
#undef PMDS
-#undef NEXT_PAGE
.data
.align 16
.skip IDT_ENTRIES * 16
__PAGE_ALIGNED_BSS
- .align PAGE_SIZE
-ENTRY(empty_zero_page)
+NEXT_PAGE(empty_zero_page)
.skip PAGE_SIZE
projects / linux-beck.git / blobdiff