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freebsd/sys/powerpc/booke/locore.S
Nathan Whitehorn 5c845fde2e Make 32-bit PowerPC kernels, like 64-bit PowerPC kernels, position-independent
executables. The goal here, not yet accomplished, is to let the e500 kernel
run under QEMU by setting KERNBASE to something that fits in low memory and
then having the kernel relocate itself at runtime.
2015-03-07 20:14:46 +00:00

756 lines
15 KiB
ArmAsm

/*-
* Copyright (C) 2007-2009 Semihalf, Rafal Jaworowski <raj@semihalf.com>
* Copyright (C) 2006 Semihalf, Marian Balakowicz <m8@semihalf.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include "assym.s"
#include <machine/asm.h>
#include <machine/hid.h>
#include <machine/param.h>
#include <machine/spr.h>
#include <machine/pte.h>
#include <machine/trap.h>
#include <machine/vmparam.h>
#include <machine/tlb.h>
#define TMPSTACKSZ 16384
.text
.globl btext
btext:
/*
* This symbol is here for the benefit of kvm_mkdb, and is supposed to
* mark the start of kernel text.
*/
.globl kernel_text
kernel_text:
/*
* Startup entry. Note, this must be the first thing in the text segment!
*/
.text
.globl __start
__start:
/*
* Assumptions on the boot loader:
* - system memory starts from physical address 0
* - it's mapped by a single TBL1 entry
* - TLB1 mapping is 1:1 pa to va
* - kernel is loaded at 16MB boundary
* - all PID registers are set to the same value
* - CPU is running in AS=0
*
* Registers contents provided by the loader(8):
* r1 : stack pointer
* r3 : metadata pointer
*
* We rearrange the TLB1 layout as follows:
* - find TLB1 entry we started in
* - make sure it's protected, ivalidate other entries
* - create temp entry in the second AS (make sure it's not TLB[1])
* - switch to temp mapping
* - map 16MB of RAM in TLB1[1]
* - use AS=1, set EPN to KERNBASE and RPN to kernel load address
* - switch to to TLB1[1] mapping
* - invalidate temp mapping
*
* locore registers use:
* r1 : stack pointer
* r2 : trace pointer (AP only, for early diagnostics)
* r3-r27 : scratch registers
* r28 : temp TLB1 entry
* r29 : initial TLB1 entry we started in
* r30-r31 : arguments (metadata pointer)
*/
/*
* Keep arguments in r30 & r31 for later use.
*/
mr %r30, %r3
mr %r31, %r4
/*
* Initial cleanup
*/
li %r3, PSL_DE /* Keep debug exceptions for CodeWarrior. */
mtmsr %r3
isync
lis %r3, HID0_E500_DEFAULT_SET@h
ori %r3, %r3, HID0_E500_DEFAULT_SET@l
mtspr SPR_HID0, %r3
isync
lis %r3, HID1_E500_DEFAULT_SET@h
ori %r3, %r3, HID1_E500_DEFAULT_SET@l
mtspr SPR_HID1, %r3
isync
/* Invalidate all entries in TLB0 */
li %r3, 0
bl tlb_inval_all
cmpwi %r30, 0
beq done_mapping
/*
* Locate the TLB1 entry that maps this code
*/
bl 1f
1: mflr %r3
bl tlb1_find_current /* the entry found is returned in r29 */
bl tlb1_inval_all_but_current
/*
* Create temporary mapping in AS=1 and switch to it
*/
addi %r3, %r29, 1
bl tlb1_temp_mapping_as1
mfmsr %r3
ori %r3, %r3, (PSL_IS | PSL_DS)
bl 2f
2: mflr %r4
addi %r4, %r4, 20
mtspr SPR_SRR0, %r4
mtspr SPR_SRR1, %r3
rfi /* Switch context */
/*
* Invalidate initial entry
*/
mr %r3, %r29
bl tlb1_inval_entry
/*
* Setup final mapping in TLB1[1] and switch to it
*/
/* Final kernel mapping, map in 16 MB of RAM */
lis %r3, MAS0_TLBSEL1@h /* Select TLB1 */
li %r4, 0 /* Entry 0 */
rlwimi %r3, %r4, 16, 12, 15
mtspr SPR_MAS0, %r3
isync
li %r3, (TLB_SIZE_64M << MAS1_TSIZE_SHIFT)@l
oris %r3, %r3, (MAS1_VALID | MAS1_IPROT)@h
mtspr SPR_MAS1, %r3 /* note TS was not filled, so it's TS=0 */
isync
lis %r3, KERNBASE@h
ori %r3, %r3, KERNBASE@l /* EPN = KERNBASE */
#ifdef SMP
ori %r3, %r3, MAS2_M@l /* WIMGE = 0b00100 */
#endif
mtspr SPR_MAS2, %r3
isync
/* Discover phys load address */
bl 3f
3: mflr %r4 /* Use current address */
rlwinm %r4, %r4, 0, 0, 7 /* 16MB alignment mask */
ori %r4, %r4, (MAS3_SX | MAS3_SW | MAS3_SR)@l
mtspr SPR_MAS3, %r4 /* Set RPN and protection */
isync
tlbwe
isync
msync
/* Switch to the above TLB1[1] mapping */
bl 4f
4: mflr %r4
rlwinm %r4, %r4, 0, 8, 31 /* Current offset from kernel load address */
rlwinm %r3, %r3, 0, 0, 19
add %r4, %r4, %r3 /* Convert to kernel virtual address */
addi %r4, %r4, 36
li %r3, PSL_DE /* Note AS=0 */
mtspr SPR_SRR0, %r4
mtspr SPR_SRR1, %r3
rfi
/*
* Invalidate temp mapping
*/
mr %r3, %r28
bl tlb1_inval_entry
done_mapping:
/*
* Setup a temporary stack
*/
bl 1f
.long tmpstack-.
1: mflr %r1
lwz %r2,0(%r1)
add %r1,%r1,%r2
addi %r1, %r1, (TMPSTACKSZ - 16)
/*
* Relocate kernel
*/
bl 1f
.long _DYNAMIC-.
.long _GLOBAL_OFFSET_TABLE_-.
1: mflr %r5
lwz %r3,0(%r5) /* _DYNAMIC in %r3 */
add %r3,%r3,%r5
lwz %r4,4(%r5) /* GOT pointer */
add %r4,%r4,%r5
lwz %r4,4(%r4) /* got[0] is _DYNAMIC link addr */
subf %r4,%r4,%r3 /* subtract to calculate relocbase */
bl elf_reloc_self
/*
* Initialise exception vector offsets
*/
bl ivor_setup
/*
* Set up arguments and jump to system initialization code
*/
mr %r3, %r30
mr %r4, %r31
/* Prepare core */
bl booke_init
/* Switch to thread0.td_kstack now */
mr %r1, %r3
li %r3, 0
stw %r3, 0(%r1)
/* Machine independet part, does not return */
bl mi_startup
/* NOT REACHED */
5: b 5b
#ifdef SMP
/************************************************************************/
/* AP Boot page */
/************************************************************************/
.text
.globl __boot_page
.align 12
__boot_page:
bl 1f
.globl bp_ntlb1s
bp_ntlb1s:
.long 0
.globl bp_tlb1
bp_tlb1:
.space 4 * 3 * 16
.globl bp_tlb1_end
bp_tlb1_end:
/*
* Initial configuration
*/
1: mflr %r31 /* r31 hold the address of bp_ntlb1s */
/* Set HIDs */
lis %r3, HID0_E500_DEFAULT_SET@h
ori %r3, %r3, HID0_E500_DEFAULT_SET@l
mtspr SPR_HID0, %r3
isync
lis %r3, HID1_E500_DEFAULT_SET@h
ori %r3, %r3, HID1_E500_DEFAULT_SET@l
mtspr SPR_HID1, %r3
isync
/* Enable branch prediction */
li %r3, BUCSR_BPEN
mtspr SPR_BUCSR, %r3
isync
/* Invalidate all entries in TLB0 */
li %r3, 0
bl tlb_inval_all
/*
* Find TLB1 entry which is translating us now
*/
bl 2f
2: mflr %r3
bl tlb1_find_current /* the entry number found is in r29 */
bl tlb1_inval_all_but_current
/*
* Create temporary translation in AS=1 and switch to it
*/
lwz %r3, 0(%r31)
bl tlb1_temp_mapping_as1
mfmsr %r3
ori %r3, %r3, (PSL_IS | PSL_DS)
bl 3f
3: mflr %r4
addi %r4, %r4, 20
mtspr SPR_SRR0, %r4
mtspr SPR_SRR1, %r3
rfi /* Switch context */
/*
* Invalidate initial entry
*/
mr %r3, %r29
bl tlb1_inval_entry
/*
* Setup final mapping in TLB1[1] and switch to it
*/
lwz %r6, 0(%r31)
addi %r5, %r31, 4
li %r4, 0
4: lis %r3, MAS0_TLBSEL1@h
rlwimi %r3, %r4, 16, 12, 15
mtspr SPR_MAS0, %r3
isync
lwz %r3, 0(%r5)
mtspr SPR_MAS1, %r3
isync
lwz %r3, 4(%r5)
mtspr SPR_MAS2, %r3
isync
lwz %r3, 8(%r5)
mtspr SPR_MAS3, %r3
isync
tlbwe
isync
msync
addi %r5, %r5, 12
addi %r4, %r4, 1
cmpw %r4, %r6
blt 4b
/* Switch to the final mapping */
bl 5f
.long __boot_page-.
5: mflr %r5
lwz %r3,0(%r3)
add %r5,%r5,%r3 /* __boot_page in r5 */
bl 6f
6: mflr %r3
rlwinm %r3, %r3, 0, 0xfff /* Offset from boot page start */
add %r3, %r3, %r5 /* Make this virtual address */
addi %r3, %r3, 32
li %r4, 0 /* Note AS=0 */
mtspr SPR_SRR0, %r3
mtspr SPR_SRR1, %r4
rfi
/*
* At this point we're running at virtual addresses KERNBASE and beyond so
* it's allowed to directly access all locations the kernel was linked
* against.
*/
/*
* Invalidate temp mapping
*/
mr %r3, %r28
bl tlb1_inval_entry
/*
* Setup a temporary stack
*/
bl 1f
.long tmpstack-.
1: mflr %r1
lwz %r2,0(%r1)
add %r1,%r1,%r2
addi %r1, %r1, (TMPSTACKSZ - 16)
/*
* Initialise exception vector offsets
*/
bl ivor_setup
/*
* Assign our pcpu instance
*/
bl 1f
.long ap_pcpu-.
1: mflr %r4
lwz %r3, 0(%r4)
add %r3, %r3, %r4
lwz %r3, 0(%r3)
mtsprg0 %r3
bl pmap_bootstrap_ap
bl cpudep_ap_bootstrap
/* Switch to the idle thread's kstack */
mr %r1, %r3
bl machdep_ap_bootstrap
/* NOT REACHED */
6: b 6b
#endif /* SMP */
/*
* Invalidate all entries in the given TLB.
*
* r3 TLBSEL
*/
tlb_inval_all:
rlwinm %r3, %r3, 3, 0x18 /* TLBSEL */
ori %r3, %r3, 0x4 /* INVALL */
tlbivax 0, %r3
isync
msync
tlbsync
msync
blr
/*
* expects address to look up in r3, returns entry number in r29
*
* FIXME: the hidden assumption is we are now running in AS=0, but we should
* retrieve actual AS from MSR[IS|DS] and put it in MAS6[SAS]
*/
tlb1_find_current:
mfspr %r17, SPR_PID0
slwi %r17, %r17, MAS6_SPID0_SHIFT
mtspr SPR_MAS6, %r17
isync
tlbsx 0, %r3
mfspr %r17, SPR_MAS0
rlwinm %r29, %r17, 16, 20, 31 /* MAS0[ESEL] -> r29 */
/* Make sure we have IPROT set on the entry */
mfspr %r17, SPR_MAS1
oris %r17, %r17, MAS1_IPROT@h
mtspr SPR_MAS1, %r17
isync
tlbwe
isync
msync
blr
/*
* Invalidates a single entry in TLB1.
*
* r3 ESEL
* r4-r5 scratched
*/
tlb1_inval_entry:
lis %r4, MAS0_TLBSEL1@h /* Select TLB1 */
rlwimi %r4, %r3, 16, 12, 15 /* Select our entry */
mtspr SPR_MAS0, %r4
isync
tlbre
li %r5, 0 /* MAS1[V] = 0 */
mtspr SPR_MAS1, %r5
isync
tlbwe
isync
msync
blr
/*
* r3 entry of temp translation
* r29 entry of current translation
* r28 returns temp entry passed in r3
* r4-r5 scratched
*/
tlb1_temp_mapping_as1:
mr %r28, %r3
/* Read our current translation */
lis %r3, MAS0_TLBSEL1@h /* Select TLB1 */
rlwimi %r3, %r29, 16, 12, 15 /* Select our current entry */
mtspr SPR_MAS0, %r3
isync
tlbre
/* Prepare and write temp entry */
lis %r3, MAS0_TLBSEL1@h /* Select TLB1 */
rlwimi %r3, %r28, 16, 12, 15 /* Select temp entry */
mtspr SPR_MAS0, %r3
isync
mfspr %r5, SPR_MAS1
li %r4, 1 /* AS=1 */
rlwimi %r5, %r4, 12, 19, 19
li %r4, 0 /* Global mapping, TID=0 */
rlwimi %r5, %r4, 16, 8, 15
oris %r5, %r5, (MAS1_VALID | MAS1_IPROT)@h
mtspr SPR_MAS1, %r5
isync
tlbwe
isync
msync
blr
/*
* Loops over TLB1, invalidates all entries skipping the one which currently
* maps this code.
*
* r29 current entry
* r3-r5 scratched
*/
tlb1_inval_all_but_current:
mr %r6, %r3
mfspr %r3, SPR_TLB1CFG /* Get number of entries */
andi. %r3, %r3, TLBCFG_NENTRY_MASK@l
li %r4, 0 /* Start from Entry 0 */
1: lis %r5, MAS0_TLBSEL1@h
rlwimi %r5, %r4, 16, 12, 15
mtspr SPR_MAS0, %r5
isync
tlbre
mfspr %r5, SPR_MAS1
cmpw %r4, %r29 /* our current entry? */
beq 2f
rlwinm %r5, %r5, 0, 2, 31 /* clear VALID and IPROT bits */
mtspr SPR_MAS1, %r5
isync
tlbwe
isync
msync
2: addi %r4, %r4, 1
cmpw %r4, %r3 /* Check if this is the last entry */
bne 1b
blr
#ifdef SMP
__boot_page_padding:
/*
* Boot page needs to be exactly 4K, with the last word of this page
* acting as the reset vector, so we need to stuff the remainder.
* Upon release from holdoff CPU fetches the last word of the boot
* page.
*/
.space 4092 - (__boot_page_padding - __boot_page)
b __boot_page
#endif /* SMP */
/************************************************************************/
/* locore subroutines */
/************************************************************************/
/*
* void tid_flush(tlbtid_t tid);
*
* Invalidate all TLB0 entries which match the given TID. Note this is
* dedicated for cases when invalidation(s) should NOT be propagated to other
* CPUs.
*
* void tid_flush(tlbtid_t tid, int tlb0_ways, int tlb0_entries_per_way);
*
* XXX: why isn't this in C?
*/
ENTRY(tid_flush)
cmpwi %r3, TID_KERNEL
beq tid_flush_end /* don't evict kernel translations */
/* Disable interrupts */
mfmsr %r10
wrteei 0
li %r6, 0 /* ways counter */
loop_ways:
li %r7, 0 /* entries [per way] counter */
loop_entries:
/* Select TLB0 and ESEL (way) */
lis %r8, MAS0_TLBSEL0@h
rlwimi %r8, %r6, 16, 14, 15
mtspr SPR_MAS0, %r8
isync
/* Select EPN (entry within the way) */
rlwinm %r8, %r7, 12, 13, 19
mtspr SPR_MAS2, %r8
isync
tlbre
/* Check if valid entry */
mfspr %r8, SPR_MAS1
andis. %r9, %r8, MAS1_VALID@h
beq next_entry /* invalid entry */
/* Check if this is our TID */
rlwinm %r9, %r8, 16, 24, 31
cmplw %r9, %r3
bne next_entry /* not our TID */
/* Clear VALID bit */
rlwinm %r8, %r8, 0, 1, 31
mtspr SPR_MAS1, %r8
isync
tlbwe
isync
msync
next_entry:
addi %r7, %r7, 1
cmpw %r7, %r5
bne loop_entries
/* Next way */
addi %r6, %r6, 1
cmpw %r6, %r4
bne loop_ways
/* Restore MSR (possibly re-enable interrupts) */
mtmsr %r10
isync
tid_flush_end:
blr
/*
* Cache disable/enable/inval sequences according
* to section 2.16 of E500CORE RM.
*/
ENTRY(dcache_inval)
/* Invalidate d-cache */
mfspr %r3, SPR_L1CSR0
ori %r3, %r3, (L1CSR0_DCFI | L1CSR0_DCLFR)@l
msync
isync
mtspr SPR_L1CSR0, %r3
isync
1: mfspr %r3, SPR_L1CSR0
andi. %r3, %r3, L1CSR0_DCFI
bne 1b
blr
ENTRY(dcache_disable)
/* Disable d-cache */
mfspr %r3, SPR_L1CSR0
li %r4, L1CSR0_DCE@l
not %r4, %r4
and %r3, %r3, %r4
msync
isync
mtspr SPR_L1CSR0, %r3
isync
blr
ENTRY(dcache_enable)
/* Enable d-cache */
mfspr %r3, SPR_L1CSR0
oris %r3, %r3, (L1CSR0_DCPE | L1CSR0_DCE)@h
ori %r3, %r3, (L1CSR0_DCPE | L1CSR0_DCE)@l
msync
isync
mtspr SPR_L1CSR0, %r3
isync
blr
ENTRY(icache_inval)
/* Invalidate i-cache */
mfspr %r3, SPR_L1CSR1
ori %r3, %r3, (L1CSR1_ICFI | L1CSR1_ICLFR)@l
isync
mtspr SPR_L1CSR1, %r3
isync
1: mfspr %r3, SPR_L1CSR1
andi. %r3, %r3, L1CSR1_ICFI
bne 1b
blr
ENTRY(icache_disable)
/* Disable i-cache */
mfspr %r3, SPR_L1CSR1
li %r4, L1CSR1_ICE@l
not %r4, %r4
and %r3, %r3, %r4
isync
mtspr SPR_L1CSR1, %r3
isync
blr
ENTRY(icache_enable)
/* Enable i-cache */
mfspr %r3, SPR_L1CSR1
oris %r3, %r3, (L1CSR1_ICPE | L1CSR1_ICE)@h
ori %r3, %r3, (L1CSR1_ICPE | L1CSR1_ICE)@l
isync
mtspr SPR_L1CSR1, %r3
isync
blr
/*
* int setfault()
*
* Similar to setjmp to setup for handling faults on accesses to user memory.
* Any routine using this may only call bcopy, either the form below,
* or the (currently used) C code optimized, so it doesn't use any non-volatile
* registers.
*/
.globl setfault
setfault:
mflr %r0
mfsprg0 %r4
lwz %r4, TD_PCB(%r2)
stw %r3, PCB_ONFAULT(%r4)
mfcr %r10
mfctr %r11
mfxer %r12
stw %r0, 0(%r3)
stw %r1, 4(%r3)
stw %r2, 8(%r3)
stmw %r10, 12(%r3) /* store CR, CTR, XER, [r13 .. r31] */
li %r3, 0 /* return FALSE */
blr
/************************************************************************/
/* Data section */
/************************************************************************/
.data
.align 3
GLOBAL(__startkernel)
.long begin
GLOBAL(__endkernel)
.long end
.align 4
tmpstack:
.space TMPSTACKSZ
tmpstackbound:
.space 10240 /* XXX: this really should not be necessary */
/*
* Compiled KERNBASE locations
*/
.globl kernbase
.set kernbase, KERNBASE
#include <powerpc/booke/trap_subr.S>