linux/arch/sparc64/kernel/head.S

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/* $Id: head.S,v 1.87 2002/02/09 19:49:31 davem Exp $
* head.S: Initial boot code for the Sparc64 port of Linux.
*
* Copyright (C) 1996,1997 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1996 David Sitsky (David.Sitsky@anu.edu.au)
* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1997 Miguel de Icaza (miguel@nuclecu.unam.mx)
*/
#include <linux/version.h>
#include <linux/errno.h>
#include <linux/threads.h>
#include <asm/thread_info.h>
#include <asm/asi.h>
#include <asm/pstate.h>
#include <asm/ptrace.h>
#include <asm/spitfire.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/errno.h>
#include <asm/signal.h>
#include <asm/processor.h>
#include <asm/lsu.h>
#include <asm/dcr.h>
#include <asm/dcu.h>
#include <asm/head.h>
#include <asm/ttable.h>
#include <asm/mmu.h>
[SPARC64]: Elminate all usage of hard-coded trap globals. UltraSPARC has special sets of global registers which are switched to for certain trap types. There is one set for MMU related traps, one set of Interrupt Vector processing, and another set (called the Alternate globals) for all other trap types. For what seems like forever we've hard coded the values in some of these trap registers. Some examples include: 1) Interrupt Vector global %g6 holds current processors interrupt work struct where received interrupts are managed for IRQ handler dispatch. 2) MMU global %g7 holds the base of the page tables of the currently active address space. 3) Alternate global %g6 held the current_thread_info() value. Such hardcoding has resulted in some serious issues in many areas. There are some code sequences where having another register available would help clean up the implementation. Taking traps such as cross-calls from the OBP firmware requires some trick code sequences wherein we have to save away and restore all of the special sets of global registers when we enter/exit OBP. We were also using the IMMU TSB register on SMP to hold the per-cpu area base address, which doesn't work any longer now that we actually use the TSB facility of the cpu. The implementation is pretty straight forward. One tricky bit is getting the current processor ID as that is different on different cpu variants. We use a stub with a fancy calling convention which we patch at boot time. The calling convention is that the stub is branched to and the (PC - 4) to return to is in register %g1. The cpu number is left in %g6. This stub can be invoked by using the __GET_CPUID macro. We use an array of per-cpu trap state to store the current thread and physical address of the current address space's page tables. The TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this table, it uses __GET_CPUID and also clobbers %g1. TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load the current processor's IRQ software state into %g6. It also uses __GET_CPUID and clobbers %g1. Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the current address space's page tables into %g7, it clobbers %g1 and uses __GET_CPUID. Many refinements are possible, as well as some tuning, with this stuff in place. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-27 07:24:22 +00:00
#include <asm/cpudata.h>
/* This section from from _start to sparc64_boot_end should fit into
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
* 0x0000000000404000 to 0x0000000000408000.
*/
.text
.globl start, _start, stext, _stext
_start:
start:
_stext:
stext:
! 0x0000000000404000
b sparc64_boot
flushw /* Flush register file. */
/* This stuff has to be in sync with SILO and other potential boot loaders
* Fields should be kept upward compatible and whenever any change is made,
* HdrS version should be incremented.
*/
.global root_flags, ram_flags, root_dev
.global sparc_ramdisk_image, sparc_ramdisk_size
.global sparc_ramdisk_image64
.ascii "HdrS"
.word LINUX_VERSION_CODE
/* History:
*
* 0x0300 : Supports being located at other than 0x4000
* 0x0202 : Supports kernel params string
* 0x0201 : Supports reboot_command
*/
.half 0x0301 /* HdrS version */
root_flags:
.half 1
root_dev:
.half 0
ram_flags:
.half 0
sparc_ramdisk_image:
.word 0
sparc_ramdisk_size:
.word 0
.xword reboot_command
.xword bootstr_info
sparc_ramdisk_image64:
.xword 0
.word _end
/* PROM cif handler code address is in %o4. */
sparc64_boot:
mov %o4, %l7
/* We need to remap the kernel. Use position independant
* code to remap us to KERNBASE.
*
* SILO can invoke us with 32-bit address masking enabled,
* so make sure that's clear.
*/
rdpr %pstate, %g1
andn %g1, PSTATE_AM, %g1
wrpr %g1, 0x0, %pstate
ba,a,pt %xcc, 1f
.globl prom_finddev_name, prom_chosen_path, prom_root_node
.globl prom_getprop_name, prom_mmu_name, prom_peer_name
.globl prom_callmethod_name, prom_translate_name, prom_root_compatible
.globl prom_map_name, prom_unmap_name, prom_mmu_ihandle_cache
.globl prom_boot_mapped_pc, prom_boot_mapping_mode
.globl prom_boot_mapping_phys_high, prom_boot_mapping_phys_low
.globl is_sun4v
prom_peer_name:
.asciz "peer"
prom_compatible_name:
.asciz "compatible"
prom_finddev_name:
.asciz "finddevice"
prom_chosen_path:
.asciz "/chosen"
prom_getprop_name:
.asciz "getprop"
prom_mmu_name:
.asciz "mmu"
prom_callmethod_name:
.asciz "call-method"
prom_translate_name:
.asciz "translate"
prom_map_name:
.asciz "map"
prom_unmap_name:
.asciz "unmap"
prom_sun4v_name:
.asciz "sun4v"
.align 4
prom_root_compatible:
.skip 64
prom_root_node:
.word 0
prom_mmu_ihandle_cache:
.word 0
prom_boot_mapped_pc:
.word 0
prom_boot_mapping_mode:
.word 0
.align 8
prom_boot_mapping_phys_high:
.xword 0
prom_boot_mapping_phys_low:
.xword 0
is_sun4v:
.word 0
1:
rd %pc, %l0
mov (1b - prom_peer_name), %l1
sub %l0, %l1, %l1
mov 0, %l2
/* prom_root_node = prom_peer(0) */
stx %l1, [%sp + 2047 + 128 + 0x00] ! service, "peer"
mov 1, %l3
stx %l3, [%sp + 2047 + 128 + 0x08] ! num_args, 1
stx %l3, [%sp + 2047 + 128 + 0x10] ! num_rets, 1
stx %l2, [%sp + 2047 + 128 + 0x18] ! arg1, 0
stx %g0, [%sp + 2047 + 128 + 0x20] ! ret1
call %l7
add %sp, (2047 + 128), %o0 ! argument array
ldx [%sp + 2047 + 128 + 0x20], %l4 ! prom root node
mov (1b - prom_root_node), %l1
sub %l0, %l1, %l1
stw %l4, [%l1]
mov (1b - prom_getprop_name), %l1
mov (1b - prom_compatible_name), %l2
mov (1b - prom_root_compatible), %l5
sub %l0, %l1, %l1
sub %l0, %l2, %l2
sub %l0, %l5, %l5
/* prom_getproperty(prom_root_node, "compatible",
* &prom_root_compatible, 64)
*/
stx %l1, [%sp + 2047 + 128 + 0x00] ! service, "getprop"
mov 4, %l3
stx %l3, [%sp + 2047 + 128 + 0x08] ! num_args, 4
mov 1, %l3
stx %l3, [%sp + 2047 + 128 + 0x10] ! num_rets, 1
stx %l4, [%sp + 2047 + 128 + 0x18] ! arg1, prom_root_node
stx %l2, [%sp + 2047 + 128 + 0x20] ! arg2, "compatible"
stx %l5, [%sp + 2047 + 128 + 0x28] ! arg3, &prom_root_compatible
mov 64, %l3
stx %l3, [%sp + 2047 + 128 + 0x30] ! arg4, size
stx %g0, [%sp + 2047 + 128 + 0x38] ! ret1
call %l7
add %sp, (2047 + 128), %o0 ! argument array
mov (1b - prom_finddev_name), %l1
mov (1b - prom_chosen_path), %l2
mov (1b - prom_boot_mapped_pc), %l3
sub %l0, %l1, %l1
sub %l0, %l2, %l2
sub %l0, %l3, %l3
stw %l0, [%l3]
sub %sp, (192 + 128), %sp
/* chosen_node = prom_finddevice("/chosen") */
stx %l1, [%sp + 2047 + 128 + 0x00] ! service, "finddevice"
mov 1, %l3
stx %l3, [%sp + 2047 + 128 + 0x08] ! num_args, 1
stx %l3, [%sp + 2047 + 128 + 0x10] ! num_rets, 1
stx %l2, [%sp + 2047 + 128 + 0x18] ! arg1, "/chosen"
stx %g0, [%sp + 2047 + 128 + 0x20] ! ret1
call %l7
add %sp, (2047 + 128), %o0 ! argument array
ldx [%sp + 2047 + 128 + 0x20], %l4 ! chosen device node
mov (1b - prom_getprop_name), %l1
mov (1b - prom_mmu_name), %l2
mov (1b - prom_mmu_ihandle_cache), %l5
sub %l0, %l1, %l1
sub %l0, %l2, %l2
sub %l0, %l5, %l5
/* prom_mmu_ihandle_cache = prom_getint(chosen_node, "mmu") */
stx %l1, [%sp + 2047 + 128 + 0x00] ! service, "getprop"
mov 4, %l3
stx %l3, [%sp + 2047 + 128 + 0x08] ! num_args, 4
mov 1, %l3
stx %l3, [%sp + 2047 + 128 + 0x10] ! num_rets, 1
stx %l4, [%sp + 2047 + 128 + 0x18] ! arg1, chosen_node
stx %l2, [%sp + 2047 + 128 + 0x20] ! arg2, "mmu"
stx %l5, [%sp + 2047 + 128 + 0x28] ! arg3, &prom_mmu_ihandle_cache
mov 4, %l3
stx %l3, [%sp + 2047 + 128 + 0x30] ! arg4, sizeof(arg3)
stx %g0, [%sp + 2047 + 128 + 0x38] ! ret1
call %l7
add %sp, (2047 + 128), %o0 ! argument array
mov (1b - prom_callmethod_name), %l1
mov (1b - prom_translate_name), %l2
sub %l0, %l1, %l1
sub %l0, %l2, %l2
lduw [%l5], %l5 ! prom_mmu_ihandle_cache
stx %l1, [%sp + 2047 + 128 + 0x00] ! service, "call-method"
mov 3, %l3
stx %l3, [%sp + 2047 + 128 + 0x08] ! num_args, 3
mov 5, %l3
stx %l3, [%sp + 2047 + 128 + 0x10] ! num_rets, 5
stx %l2, [%sp + 2047 + 128 + 0x18] ! arg1: "translate"
stx %l5, [%sp + 2047 + 128 + 0x20] ! arg2: prom_mmu_ihandle_cache
/* PAGE align */
srlx %l0, 13, %l3
sllx %l3, 13, %l3
stx %l3, [%sp + 2047 + 128 + 0x28] ! arg3: vaddr, our PC
stx %g0, [%sp + 2047 + 128 + 0x30] ! res1
stx %g0, [%sp + 2047 + 128 + 0x38] ! res2
stx %g0, [%sp + 2047 + 128 + 0x40] ! res3
stx %g0, [%sp + 2047 + 128 + 0x48] ! res4
stx %g0, [%sp + 2047 + 128 + 0x50] ! res5
call %l7
add %sp, (2047 + 128), %o0 ! argument array
ldx [%sp + 2047 + 128 + 0x40], %l1 ! translation mode
mov (1b - prom_boot_mapping_mode), %l4
sub %l0, %l4, %l4
stw %l1, [%l4]
mov (1b - prom_boot_mapping_phys_high), %l4
sub %l0, %l4, %l4
ldx [%sp + 2047 + 128 + 0x48], %l2 ! physaddr high
stx %l2, [%l4 + 0x0]
ldx [%sp + 2047 + 128 + 0x50], %l3 ! physaddr low
/* 4MB align */
srlx %l3, 22, %l3
sllx %l3, 22, %l3
stx %l3, [%l4 + 0x8]
/* Leave service as-is, "call-method" */
mov 7, %l3
stx %l3, [%sp + 2047 + 128 + 0x08] ! num_args, 7
mov 1, %l3
stx %l3, [%sp + 2047 + 128 + 0x10] ! num_rets, 1
mov (1b - prom_map_name), %l3
sub %l0, %l3, %l3
stx %l3, [%sp + 2047 + 128 + 0x18] ! arg1: "map"
/* Leave arg2 as-is, prom_mmu_ihandle_cache */
mov -1, %l3
stx %l3, [%sp + 2047 + 128 + 0x28] ! arg3: mode (-1 default)
sethi %hi(8 * 1024 * 1024), %l3
stx %l3, [%sp + 2047 + 128 + 0x30] ! arg4: size (8MB)
sethi %hi(KERNBASE), %l3
stx %l3, [%sp + 2047 + 128 + 0x38] ! arg5: vaddr (KERNBASE)
stx %g0, [%sp + 2047 + 128 + 0x40] ! arg6: empty
mov (1b - prom_boot_mapping_phys_low), %l3
sub %l0, %l3, %l3
ldx [%l3], %l3
stx %l3, [%sp + 2047 + 128 + 0x48] ! arg7: phys addr
call %l7
add %sp, (2047 + 128), %o0 ! argument array
add %sp, (192 + 128), %sp
sethi %hi(prom_root_compatible), %g1
or %g1, %lo(prom_root_compatible), %g1
sethi %hi(prom_sun4v_name), %g7
or %g7, %lo(prom_sun4v_name), %g7
mov 5, %g3
1: ldub [%g7], %g2
ldub [%g1], %g4
cmp %g2, %g4
bne,pn %icc, 2f
add %g7, 1, %g7
subcc %g3, 1, %g3
bne,pt %xcc, 1b
add %g1, 1, %g1
sethi %hi(is_sun4v), %g1
or %g1, %lo(is_sun4v), %g1
mov 1, %g7
stw %g7, [%g1]
2:
BRANCH_IF_SUN4V(g1, jump_to_sun4u_init)
BRANCH_IF_CHEETAH_BASE(g1,g7,cheetah_boot)
BRANCH_IF_CHEETAH_PLUS_OR_FOLLOWON(g1,g7,cheetah_plus_boot)
ba,pt %xcc, spitfire_boot
nop
cheetah_plus_boot:
/* Preserve OBP chosen DCU and DCR register settings. */
ba,pt %xcc, cheetah_generic_boot
nop
cheetah_boot:
mov DCR_BPE | DCR_RPE | DCR_SI | DCR_IFPOE | DCR_MS, %g1
wr %g1, %asr18
sethi %uhi(DCU_ME|DCU_RE|DCU_HPE|DCU_SPE|DCU_SL|DCU_WE), %g7
or %g7, %ulo(DCU_ME|DCU_RE|DCU_HPE|DCU_SPE|DCU_SL|DCU_WE), %g7
sllx %g7, 32, %g7
or %g7, DCU_DM | DCU_IM | DCU_DC | DCU_IC, %g7
stxa %g7, [%g0] ASI_DCU_CONTROL_REG
membar #Sync
cheetah_generic_boot:
mov TSB_EXTENSION_P, %g3
stxa %g0, [%g3] ASI_DMMU
stxa %g0, [%g3] ASI_IMMU
membar #Sync
mov TSB_EXTENSION_S, %g3
stxa %g0, [%g3] ASI_DMMU
membar #Sync
mov TSB_EXTENSION_N, %g3
stxa %g0, [%g3] ASI_DMMU
stxa %g0, [%g3] ASI_IMMU
membar #Sync
ba,a,pt %xcc, jump_to_sun4u_init
spitfire_boot:
/* Typically PROM has already enabled both MMU's and both on-chip
* caches, but we do it here anyway just to be paranoid.
*/
mov (LSU_CONTROL_IC|LSU_CONTROL_DC|LSU_CONTROL_IM|LSU_CONTROL_DM), %g1
stxa %g1, [%g0] ASI_LSU_CONTROL
membar #Sync
jump_to_sun4u_init:
/*
* Make sure we are in privileged mode, have address masking,
* using the ordinary globals and have enabled floating
* point.
*
* Again, typically PROM has left %pil at 13 or similar, and
* (PSTATE_PRIV | PSTATE_PEF | PSTATE_IE) in %pstate.
*/
wrpr %g0, (PSTATE_PRIV|PSTATE_PEF|PSTATE_IE), %pstate
wr %g0, 0, %fprs
set sun4u_init, %g2
jmpl %g2 + %g0, %g0
nop
sun4u_init:
BRANCH_IF_SUN4V(g1, sun4v_init)
/* Set ctx 0 */
mov PRIMARY_CONTEXT, %g7
stxa %g0, [%g7] ASI_DMMU
membar #Sync
mov SECONDARY_CONTEXT, %g7
stxa %g0, [%g7] ASI_DMMU
membar #Sync
ba,pt %xcc, sun4u_continue
nop
sun4v_init:
/* Set ctx 0 */
mov PRIMARY_CONTEXT, %g7
stxa %g0, [%g7] ASI_MMU
membar #Sync
mov SECONDARY_CONTEXT, %g7
stxa %g0, [%g7] ASI_MMU
membar #Sync
ba,pt %xcc, niagara_tlb_fixup
nop
sun4u_continue:
BRANCH_IF_ANY_CHEETAH(g1, g7, cheetah_tlb_fixup)
ba,pt %xcc, spitfire_tlb_fixup
nop
niagara_tlb_fixup:
mov 3, %g2 /* Set TLB type to hypervisor. */
sethi %hi(tlb_type), %g1
stw %g2, [%g1 + %lo(tlb_type)]
/* Patch copy/clear ops. */
call niagara_patch_copyops
nop
call niagara_patch_bzero
nop
call niagara_patch_pageops
nop
/* Patch TLB/cache ops. */
call hypervisor_patch_cachetlbops
nop
ba,pt %xcc, tlb_fixup_done
nop
cheetah_tlb_fixup:
mov 2, %g2 /* Set TLB type to cheetah+. */
BRANCH_IF_CHEETAH_PLUS_OR_FOLLOWON(g1,g7,1f)
mov 1, %g2 /* Set TLB type to cheetah. */
1: sethi %hi(tlb_type), %g1
stw %g2, [%g1 + %lo(tlb_type)]
/* Patch copy/page operations to cheetah optimized versions. */
call cheetah_patch_copyops
nop
call cheetah_patch_copy_page
nop
call cheetah_patch_cachetlbops
nop
ba,pt %xcc, tlb_fixup_done
nop
spitfire_tlb_fixup:
/* Set TLB type to spitfire. */
mov 0, %g2
sethi %hi(tlb_type), %g1
stw %g2, [%g1 + %lo(tlb_type)]
tlb_fixup_done:
sethi %hi(init_thread_union), %g6
or %g6, %lo(init_thread_union), %g6
ldx [%g6 + TI_TASK], %g4
mov %sp, %l6
wr %g0, ASI_P, %asi
mov 1, %g1
sllx %g1, THREAD_SHIFT, %g1
sub %g1, (STACKFRAME_SZ + STACK_BIAS), %g1
add %g6, %g1, %sp
mov 0, %fp
/* Set per-cpu pointer initially to zero, this makes
* the boot-cpu use the in-kernel-image per-cpu areas
* before setup_per_cpu_area() is invoked.
*/
clr %g5
wrpr %g0, 0, %wstate
wrpr %g0, 0x0, %tl
/* Clear the bss */
sethi %hi(__bss_start), %o0
or %o0, %lo(__bss_start), %o0
sethi %hi(_end), %o1
or %o1, %lo(_end), %o1
call __bzero
sub %o1, %o0, %o1
#ifdef CONFIG_LOCKDEP
/* We have this call this super early, as even prom_init can grab
* spinlocks and thus call into the lockdep code.
*/
call lockdep_init
nop
#endif
mov %l6, %o1 ! OpenPROM stack
call prom_init
mov %l7, %o0 ! OpenPROM cif handler
/* Initialize current_thread_info()->cpu as early as possible.
* In order to do that accurately we have to patch up the get_cpuid()
* assembler sequences. And that, in turn, requires that we know
* if we are on a Starfire box or not. While we're here, patch up
* the sun4v sequences as well.
*/
call check_if_starfire
nop
call per_cpu_patch
nop
call sun4v_patch
nop
#ifdef CONFIG_SMP
call hard_smp_processor_id
nop
cmp %o0, NR_CPUS
blu,pt %xcc, 1f
nop
call boot_cpu_id_too_large
nop
/* Not reached... */
1:
#else
mov 0, %o0
#endif
sth %o0, [%g6 + TI_CPU]
/* Off we go.... */
call start_kernel
nop
/* Not reached... */
/* This is meant to allow the sharing of this code between
* boot processor invocation (via setup_tba() below) and
* secondary processor startup (via trampoline.S). The
* former does use this code, the latter does not yet due
* to some complexities. That should be fixed up at some
* point.
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
*
* There used to be enormous complexity wrt. transferring
* over from the firwmare's trap table to the Linux kernel's.
* For example, there was a chicken & egg problem wrt. building
* the OBP page tables, yet needing to be on the Linux kernel
* trap table (to translate PAGE_OFFSET addresses) in order to
* do that.
*
* We now handle OBP tlb misses differently, via linear lookups
* into the prom_trans[] array. So that specific problem no
* longer exists. Yet, unfortunately there are still some issues
* preventing trampoline.S from using this code... ho hum.
*/
.globl setup_trap_table
setup_trap_table:
save %sp, -192, %sp
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
/* Force interrupts to be disabled. */
rdpr %pstate, %l0
andn %l0, PSTATE_IE, %o1
wrpr %o1, 0x0, %pstate
rdpr %pil, %l1
wrpr %g0, 15, %pil
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
/* Make the firmware call to jump over to the Linux trap table. */
sethi %hi(is_sun4v), %o0
lduw [%o0 + %lo(is_sun4v)], %o0
brz,pt %o0, 1f
nop
TRAP_LOAD_TRAP_BLOCK(%g2, %g3)
add %g2, TRAP_PER_CPU_FAULT_INFO, %g2
stxa %g2, [%g0] ASI_SCRATCHPAD
/* Compute physical address:
*
* paddr = kern_base + (mmfsa_vaddr - KERNBASE)
*/
sethi %hi(KERNBASE), %g3
sub %g2, %g3, %g2
sethi %hi(kern_base), %g3
ldx [%g3 + %lo(kern_base)], %g3
add %g2, %g3, %o1
call prom_set_trap_table_sun4v
sethi %hi(sparc64_ttable_tl0), %o0
ba,pt %xcc, 2f
nop
1: call prom_set_trap_table
sethi %hi(sparc64_ttable_tl0), %o0
/* Start using proper page size encodings in ctx register. */
2: sethi %hi(sparc64_kern_pri_context), %g3
ldx [%g3 + %lo(sparc64_kern_pri_context)], %g2
mov PRIMARY_CONTEXT, %g1
661: stxa %g2, [%g1] ASI_DMMU
.section .sun4v_1insn_patch, "ax"
.word 661b
stxa %g2, [%g1] ASI_MMU
.previous
membar #Sync
/* Kill PROM timer */
sethi %hi(0x80000000), %o2
sllx %o2, 32, %o2
wr %o2, 0, %tick_cmpr
BRANCH_IF_SUN4V(o2, 1f)
BRANCH_IF_ANY_CHEETAH(o2, o3, 1f)
ba,pt %xcc, 2f
nop
/* Disable STICK_INT interrupts. */
1:
sethi %hi(0x80000000), %o2
sllx %o2, 32, %o2
wr %o2, %asr25
2:
wrpr %g0, %g0, %wstate
call init_irqwork_curcpu
nop
/* Now we can restore interrupt state. */
wrpr %l0, 0, %pstate
wrpr %l1, 0x0, %pil
ret
restore
.globl setup_tba
setup_tba:
save %sp, -192, %sp
/* The boot processor is the only cpu which invokes this
* routine, the other cpus set things up via trampoline.S.
* So save the OBP trap table address here.
*/
rdpr %tba, %g7
sethi %hi(prom_tba), %o1
or %o1, %lo(prom_tba), %o1
stx %g7, [%o1]
call setup_trap_table
nop
ret
restore
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
sparc64_boot_end:
#include "etrap.S"
#include "rtrap.S"
#include "winfixup.S"
#include "entry.S"
#include "sun4v_tlb_miss.S"
#include "sun4v_ivec.S"
#include "ktlb.S"
#include "tsb.S"
/*
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
* The following skip makes sure the trap table in ttable.S is aligned
* on a 32K boundary as required by the v9 specs for TBA register.
*
* We align to a 32K boundary, then we have the 32K kernel TSB,
* the 64K kernel 4MB TSB, and then the 32K aligned trap table.
*/
[SPARC64]: Fix boot failures on SunBlade-150 The sequence to move over to the Linux trap tables from the firmware ones needs to be more air tight. It turns out that to be %100 safe we do need to be able to translate OBP mappings in our TLB miss handlers early. In order not to eat up a lot of kernel image memory with static page tables, just use the translations array in the OBP TLB miss handlers. That solves the bulk of the problem. Furthermore, to make sure the OBP TLB miss path will work even before the fixed MMU globals are loaded, explicitly load %g1 to TLB_SFSR at the beginning of the i-TLB and d-TLB miss handlers. To ease the OBP TLB miss walking of the prom_trans[] array, we sort it then delete all of the non-OBP entries in there (for example, there are entries for the kernel image itself which we're not interested in at all). We also save about 32K of kernel image size with this change. Not a bad side effect :-) There are still some reasons why trampoline.S can't use the setup_trap_table() yet. The most noteworthy are: 1) OBP boots secondary processors with non-bias'd stack for some reason. This is easily fixed by using a small bootup stack in the kernel image explicitly for this purpose. 2) Doing a firmware call via the normal C call prom_set_trap_table() goes through the whole OBP enter/exit sequence that saves and restores OBP and Linux kernel state in the MMUs. This path unfortunately does a "flush %g6" while loading up the OBP locked TLB entries for the firmware call. If we setup the %g6 in the trampoline.S code properly, that is in the PAGE_OFFSET linear mapping, but we're not on the kernel trap table yet so those addresses won't translate properly. One idea is to do a by-hand firmware call like we do in the early bootup code and elsewhere here in trampoline.S But this fails as well, as aparently the secondary processors are not booted with OBP's special locked TLB entries loaded. These are necessary for the firwmare to processes TLB misses correctly up until the point where we take over the trap table. This does need to be resolved at some point. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-12 19:22:46 +00:00
1:
.skip 0x4000 + _start - 1b
! 0x0000000000408000
.globl swapper_tsb
swapper_tsb:
.skip (32 * 1024)
.globl swapper_4m_tsb
swapper_4m_tsb:
.skip (64 * 1024)
! 0x0000000000420000
/* Some care needs to be exercised if you try to move the
* location of the trap table relative to other things. For
* one thing there are br* instructions in some of the
* trap table entires which branch back to code in ktlb.S
* Those instructions can only handle a signed 16-bit
* displacement.
*
* There is a binutils bug (bugzilla #4558) which causes
* the relocation overflow checks for such instructions to
* not be done correctly. So bintuils will not notice the
* error and will instead write junk into the relocation and
* you'll have an unbootable kernel.
*/
#include "ttable.S"
! 0x0000000000428000
#include "systbls.S"
.data
.align 8
.globl prom_tba, tlb_type
prom_tba: .xword 0
tlb_type: .word 0 /* Must NOT end up in BSS */
.section ".fixup",#alloc,#execinstr
.globl __ret_efault, __retl_efault
__ret_efault:
ret
restore %g0, -EFAULT, %o0
__retl_efault:
retl
mov -EFAULT, %o0