ref: d5fc608059dee5f65ddfdf3e230bb8d458ccf43f
dir: /sys/src/9/teg2/l.s/
/*
* tegra 2 SoC machine assist
* dual arm cortex-a9 processors
*
* ARM v7 arch. ref. man. §B1.3.3 says that we don't need barriers
* around writes to CPSR.
*
* LDREX/STREX use an exclusive monitor, which is part of the data cache unit
* for the L1 cache, so they won't work right if the L1 cache is disabled.
*/
#include "arm.s"
#define LDREX(fp,t) WORD $(0xe<<28|0x01900f9f | (fp)<<16 | (t)<<12)
/* `The order of operands is from left to right in dataflow order' - asm man */
#define STREX(f,tp,r) WORD $(0xe<<28|0x01800f90 | (tp)<<16 | (r)<<12 | (f)<<0)
#define MAXMB (KiB-1) /* last MB has vectors */
#define TMPSTACK (DRAMSIZE - 64*MiB) /* used only during cpu startup */
/* tas/cas strex debugging limits; started at 10000 */
#define MAXSC 100000
GLOBL testmem(SB), $4
/*
* Entered here from Das U-Boot or another Plan 9 kernel with MMU disabled.
* Until the MMU is enabled it is OK to call functions provided
* they are within ±32MiB relative and do not require any
* local variables or more than one argument (i.e. there is
* no stack).
*/
TEXT _start(SB), 1, $-4
CPSMODE(PsrMsvc)
CPSID /* interrupts off */
CPSAE
SETEND(0) /* little-endian */
BARRIERS
CLREX
SETZSB
MOVW CPSR, R0
ORR $PsrDfiq, R0
MOVW R0, CPSR
/* invalidate i-cache and branch-target cache */
MTCP CpSC, 0, PC, C(CpCACHE), C(CpCACHEinvi), CpCACHEall
BARRIERS
/* put cpus other than 0 to sleep until cpu 0 is ready */
CPUID(R1)
BEQ cpuinit
/* not cpu 0 */
PUTC('Z')
PUTC('Z')
BARRIERS
dowfi:
WFI
MOVW cpus_proceed(SB), R1
CMP $0, R1
BEQ dowfi
BL cpureset(SB)
B dowfi
cpuinit:
DELAY(printloopret, 1)
PUTC('\r')
DELAY(printloopnl, 1)
PUTC('\n')
DELAY(printloops, 1)
PUTC('P')
/* disable the PL310 L2 cache on cpu0 */
MOVW $(PHYSL2BAG+0x100), R1
MOVW $0, R2
MOVW R2, (R1)
BARRIERS
/* invalidate it */
MOVW $((1<<16)-1), R2
MOVW R2, 0x77c(R1)
BARRIERS
/*
* disable my MMU & caches
*/
MFCP CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl
ORR $CpCsbo, R1
BIC $(CpCsbz|CpCmmu|CpCdcache|CpCicache|CpCpredict), R1
MTCP CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl
BARRIERS
/* cortex-a9 model-specific initial configuration */
MOVW $0, R1
MTCP CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl
BARRIERS
PUTC('l')
DELAY(printloop3, 1)
MOVW $testmem-KZERO(SB), R0
BL memdiag(SB)
PUTC('a')
/* clear Mach for cpu 0 */
MOVW $PADDR(MACHADDR), R4 /* address of Mach for cpu 0 */
MOVW $0, R0
_machZ:
MOVW R0, (R4)
ADD $4, R4
CMP.S $PADDR(L1+L1X(0)), R4 /* end at top-level page table */
BNE _machZ
/*
* set up the MMU page table for cpu 0
*/
PUTC('n')
/* clear all PTEs first, to provide a default */
// MOVW $PADDR(L1+L1X(0)), R4 /* address of PTE for 0 */
_ptenv0:
ZEROPTE()
CMP.S $PADDR(L1+16*KiB), R4
BNE _ptenv0
DELAY(printloop4, 2)
PUTC(' ')
/*
* set up double map of PHYSDRAM, KZERO to PHYSDRAM for first few MBs,
* but only if KZERO and PHYSDRAM differ.
*/
MOVW $PTEDRAM, R2 /* PTE bits */
MOVW $PHYSDRAM, R3 /* pa */
CMP $KZERO, R3
BEQ no2map
MOVW $PADDR(L1+L1X(PHYSDRAM)), R4 /* address of PTE for PHYSDRAM */
MOVW $DOUBLEMAPMBS, R5
_ptdbl:
FILLPTE()
SUB.S $1, R5
BNE _ptdbl
no2map:
/*
* back up and fill in PTEs for memory at KZERO.
* trimslice has 1 bank of 1GB at PHYSDRAM.
* Map the maximum.
*/
PUTC('9')
MOVW $PTEDRAM, R2 /* PTE bits */
MOVW $PHYSDRAM, R3
MOVW $PADDR(L1+L1X(KZERO)), R4 /* start with PTE for KZERO */
MOVW $MAXMB, R5 /* inner loop count (MBs) */
_ptekrw: /* set PTEs */
FILLPTE()
SUB.S $1, R5 /* decrement inner loop count */
BNE _ptekrw
/*
* back up and fill in PTEs for MMIO
*/
PUTC(' ')
MOVW $PTEIO, R2 /* PTE bits */
MOVW $PHYSIO, R3
MOVW $PADDR(L1+L1X(VIRTIO)), R4 /* start with PTE for VIRTIO */
_ptenv2:
FILLPTE()
CMP.S $PADDR(L1+L1X(PHYSIOEND)), R4
BNE _ptenv2
/* mmu.c sets up the trap vectors later */
MOVW $(PHYSDRAM | TMPSTACK), SP
/*
* learn l1 cache characteristics (on cpu 0 only).
*/
MOVW $(1-1), R0 /* l1 */
SLL $1, R0 /* R0 = (cache - 1) << 1 */
MTCP CpSC, CpIDcssel, R0, C(CpID), C(CpIDid), 0 /* select l1 cache */
BARRIERS
MFCP CpSC, CpIDcsize, R0, C(CpID), C(CpIDid), 0 /* get sets & ways */
MOVW $CACHECONF, R8
/* get log2linelen into l1setsh */
MOVW R0, R1
AND $3, R1
ADD $4, R1
/* l1 & l2 must have same cache line size, thus same set shift */
MOVW R1, 4(R8) /* +4 = l1setsh */
MOVW R1, 12(R8) /* +12 = l2setsh */
/* get nways in R1 */
SRA $3, R0, R1
AND $((1<<10)-1), R1
ADD $1, R1
/* get log2(nways) in R2 (assume nways is 2^n) */
MOVW $(BI2BY*BY2WD - 1), R2
CLZ(1, 1)
SUB.S R1, R2 /* R2 = 31 - clz(nways) */
ADD.EQ $1, R2
// MOVW R2, R3 /* print log2(nways): 2 */
MOVW $32, R1
SUB R2, R1 /* R1 = 32 - log2(nways) */
MOVW R1, 0(R8) /* +0 = l1waysh */
BARRIERS
MOVW $testmem-KZERO(SB), R0
BL memdiag(SB)
/*
* the mpcore manual says invalidate d-cache, scu, pl310 in that order,
* but says nothing about when to disable them.
*
* invalidate my caches before enabling
*/
BL cachedinv(SB)
MTCP CpSC, 0, PC, C(CpCACHE), C(CpCACHEinvi), CpCACHEall
BARRIERS
PUTC('f')
/*
* the mpcore manual says enable scu, d-cache, pl310, smp mode
* in that order. we have to reverse the last two; see main().
*/
BL scuon(SB)
/*
* turn my L1 cache on; need it for tas below.
*/
MFCP CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl
ORR $(CpCdcache|CpCicache|CpCalign|CpCpredict), R1
MTCP CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl
BARRIERS
/* cortex-a9 model-specific configuration */
MOVW $CpACl1pref, R1
MTCP CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl
BARRIERS
/* we're supposed to wait until l1 & l2 are on before calling smpon */
PUTC('r')
/* set the domain access control */
MOVW $Client, R0
BL dacput(SB)
DELAY(printloop5, 2)
PUTC('o')
BL mmuinvalidate(SB)
MOVW $0, R0
BL pidput(SB)
/* set the translation table base */
MOVW $PADDR(L1), R0
BL ttbput(SB)
PUTC('m')
/*
* the little dance to turn the MMU on
*/
BL cacheuwbinv(SB)
BL mmuinvalidate(SB)
BL mmuenable(SB)
PUTC(' ')
/* warp the PC into the virtual map */
MOVW $KZERO, R0
BL _r15warp(SB)
/*
* cpu 0 is now running at KZERO+something!
*/
BARRIERS
MOVW $setR12(SB), R12 /* reload kernel SB */
MOVW $(KZERO | TMPSTACK), SP
BL cacheuwbinv(SB)
PUTC('B')
MOVW $PHYSDRAM, R3 /* pa */
CMP $KZERO, R3
BEQ no2unmap
/* undo double map of PHYSDRAM, KZERO & first few MBs */
MOVW $(L1+L1X(PHYSDRAM)), R4 /* addr. of PTE for PHYSDRAM */
MOVW $0, R0
MOVW $DOUBLEMAPMBS, R5
_ptudbl:
ZEROPTE()
SUB.S $1, R5
BNE _ptudbl
no2unmap:
BL cachedwb(SB)
BL mmuinvalidate(SB)
/*
* call main in C
* pass Mach to main and set up the stack in it
*/
MOVW $MACHADDR, R0 /* cpu 0 Mach */
MOVW R0, R(MACH) /* m = MACHADDR */
ADD $(MACHSIZE-4), R0, SP /* leave space for link register */
PUTC('e')
BL main(SB) /* main(m) */
limbo:
BL idlehands(SB)
B limbo
BL _div(SB) /* hack to load _div, etc. */
/*
* called on cpu(s) other than 0, to start them, from _vrst
* (reset vector) in lexception.s, with interrupts disabled
* and in SVC mode, running in the zero segment (pc is in lower 256MB).
* SB is set for the zero segment.
*/
TEXT cpureset(SB), 1, $-4
CLREX
MOVW CPSR, R0
ORR $PsrDfiq, R0
MOVW R0, CPSR
MOVW $(PHYSDRAM | TMPSTACK), SP /* stack for cache ops */
/* paranoia: turn my mmu and caches off. */
MFCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
ORR $CpCsbo, R0
BIC $(CpCsbz|CpCmmu|CpCdcache|CpCicache|CpCpredict), R0
MTCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
BARRIERS
/* cortex-a9 model-specific initial configuration */
MOVW $0, R1
MTCP CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl
ISB
/* invalidate my caches before enabling */
BL cachedinv(SB)
MTCP CpSC, 0, PC, C(CpCACHE), C(CpCACHEinvi), CpCACHEall
BARRIERS
/*
* turn my L1 cache on; need it (and mmu) for tas below.
* need branch prediction to make delay() timing right.
*/
MFCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
ORR $(CpCdcache|CpCicache|CpCalign|CpCpredict), R0
MTCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
BARRIERS
/* enable l1 caches coherency, at minimum for ldrex/strex. */
BL smpon(SB)
BARRIERS
/*
* we used to write to PHYSEVP here; now we do it in C, which offers
* more assurance that we're up and won't go off the rails.
*/
/* set the domain access control */
MOVW $Client, R0
BL dacput(SB)
BL setmach(SB)
/*
* redo double map of PHYSDRAM, KZERO in this cpu's ptes.
* mmuinit will undo this later.
*/
MOVW $PHYSDRAM, R3
CMP $KZERO, R3
BEQ noun2map
/* launchinit set m->mmul1 to a copy of cpu0's l1 page table */
MOVW 12(R(MACH)), R0 /* m->mmul1 (virtual addr) */
BL k2paddr(SB) /* R0 = PADDR(m->mmul1) */
ADD $L1X(PHYSDRAM), R0, R4 /* R4 = address of PHYSDRAM's PTE */
MOVW $PTEDRAM, R2 /* PTE bits */
MOVW $DOUBLEMAPMBS, R5
_ptrdbl:
ORR R3, R2, R1 /* first identity-map 0 to 0, etc. */
MOVW R1, (R4)
ADD $4, R4 /* bump PTE address */
ADD $MiB, R3 /* bump pa */
SUB.S $1, R5
BNE _ptrdbl
noun2map:
MOVW $0, R0
BL pidput(SB)
/* set the translation table base to PADDR(m->mmul1) */
MOVW 12(R(MACH)), R0 /* m->mmul1 */
BL k2paddr(SB) /* R0 = PADDR(m->mmul1) */
BL ttbput(SB)
/*
* the little dance to turn the MMU on
*/
BL cacheuwbinv(SB)
BL mmuinvalidate(SB)
BL mmuenable(SB)
/*
* mmu is now on, with l1 pt at m->mmul1.
*/
/* warp the PC into the virtual map */
MOVW $KZERO, R0
BL _r15warp(SB)
/*
* now running at KZERO+something!
*/
BARRIERS
MOVW $setR12(SB), R12 /* reload kernel's SB */
MOVW $(KZERO | TMPSTACK), SP /* stack for cache ops*/
BL setmach(SB)
ADD $(MACHSIZE-4), R(MACH), SP /* leave space for link register */
BL cpustart(SB)
/*
* converts virtual address in R0 to a physical address.
*/
TEXT k2paddr(SB), 1, $-4
BIC $KSEGM, R0
ADD $PHYSDRAM, R0
RET
/*
* converts physical address in R0 to a virtual address.
*/
TEXT p2kaddr(SB), 1, $-4
BIC $KSEGM, R0
ORR $KZERO, R0
RET
/*
* converts address in R0 to the current segment, as defined by the PC.
* clobbers R1.
*/
TEXT addr2pcseg(SB), 1, $-4
BIC $KSEGM, R0
MOVW PC, R1
AND $KSEGM, R1 /* segment PC is in */
ORR R1, R0
RET
/* sets R(MACH), preserves other registers */
TEXT setmach(SB), 1, $-4
MOVM.DB.W [R14], (R13)
MOVM.DB.W [R0-R2], (R13)
CPUID(R2)
SLL $2, R2 /* convert to word index */
MOVW $machaddr(SB), R0
BL addr2pcseg(SB)
ADD R2, R0 /* R0 = &machaddr[cpuid] */
MOVW (R0), R0 /* R0 = machaddr[cpuid] */
CMP $0, R0
MOVW.EQ $MACHADDR, R0 /* paranoia: use MACHADDR if 0 */
BL addr2pcseg(SB)
MOVW R0, R(MACH) /* m = machaddr[cpuid] */
MOVM.IA.W (R13), [R0-R2]
MOVM.IA.W (R13), [R14]
RET
/*
* memory diagnostic
* tests word at (R0); modifies R7 and R8
*/
TEXT memdiag(SB), 1, $-4
MOVW $0xabcdef89, R7
MOVW R7, (R0)
MOVW (R0), R8
CMP R7, R8
BNE mbuggery /* broken memory */
BARRIERS
MOVW (R0), R8
CMP R7, R8
BNE mbuggery /* broken memory */
MOVW $0, R7
MOVW R7, (R0)
BARRIERS
RET
/* modifies R0, R3—R6 */
TEXT printhex(SB), 1, $-4
MOVW R0, R3
PUTC('0')
PUTC('x')
MOVW $(32-4), R5 /* bits to shift right */
nextdig:
SRA R5, R3, R4
AND $0xf, R4
ADD $'0', R4
CMP.S $'9', R4
BLE nothex /* if R4 <= 9, jump */
ADD $('a'-('9'+1)), R4
nothex:
PUTC(R4)
SUB.S $4, R5
BGE nextdig
PUTC('\r')
PUTC('\n')
DELAY(proct, 50)
RET
mbuggery:
PUTC('?')
PUTC('m')
mtopanic:
MOVW $membmsg(SB), R0
MOVW R14, R1 /* get R14's segment ... */
AND $KSEGM, R1
BIC $KSEGM, R0 /* strip segment from address */
ORR R1, R0 /* combine them */
BL panic(SB)
mbugloop:
WFI
B mbugloop
DATA membmsg+0(SB)/8,$"memory b"
DATA membmsg+8(SB)/6,$"roken\z"
GLOBL membmsg(SB), $14
TEXT _r15warp(SB), 1, $-4
BIC $KSEGM, R14 /* link reg, will become PC */
ORR R0, R14
BIC $KSEGM, SP
ORR R0, SP
RET
/*
* `single-element' cache operations.
* in arm arch v7, they operate on all architected cache levels, so separate
* l2 functions are usually unnecessary.
*/
TEXT cachedwbse(SB), $-4 /* D writeback SE */
MOVW R0, R2
MOVW CPSR, R3
CPSID /* splhi */
BARRIERS /* force outstanding stores to cache */
MOVW R2, R0
MOVW 4(FP), R1
ADD R0, R1 /* R1 is end address */
BIC $(CACHELINESZ-1), R0 /* cache line start */
_dwbse:
MTCP CpSC, 0, R0, C(CpCACHE), C(CpCACHEwb), CpCACHEse
ADD $CACHELINESZ, R0
CMP.S R0, R1
BGT _dwbse
B _wait
TEXT cachedwbinvse(SB), $-4 /* D writeback+invalidate SE */
MOVW R0, R2
MOVW CPSR, R3
CPSID /* splhi */
BARRIERS /* force outstanding stores to cache */
MOVW R2, R0
MOVW 4(FP), R1
ADD R0, R1 /* R1 is end address */
BIC $(CACHELINESZ-1), R0 /* cache line start */
_dwbinvse:
MTCP CpSC, 0, R0, C(CpCACHE), C(CpCACHEwbi), CpCACHEse
ADD $CACHELINESZ, R0
CMP.S R0, R1
BGT _dwbinvse
_wait: /* drain write buffer */
BARRIERS
MOVW R3, CPSR /* splx */
RET
TEXT cachedinvse(SB), $-4 /* D invalidate SE */
MOVW R0, R2
MOVW CPSR, R3
CPSID /* splhi */
BARRIERS /* force outstanding stores to cache */
MOVW R2, R0
MOVW 4(FP), R1
ADD R0, R1 /* R1 is end address */
/*
* if start & end addresses are not on cache-line boundaries,
* flush first & last cache lines before invalidating.
*/
AND.S $(CACHELINESZ-1), R0, R4
BEQ stok
BIC $(CACHELINESZ-1), R0, R4 /* cache line start */
MTCP CpSC, 0, R4, C(CpCACHE), C(CpCACHEwb), CpCACHEse
stok:
AND.S $(CACHELINESZ-1), R1, R4
BEQ endok
BIC $(CACHELINESZ-1), R1, R4 /* cache line start */
MTCP CpSC, 0, R4, C(CpCACHE), C(CpCACHEwb), CpCACHEse
endok:
BIC $(CACHELINESZ-1), R0 /* cache line start */
_dinvse:
MTCP CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvd), CpCACHEse
ADD $CACHELINESZ, R0
CMP.S R0, R1
BGT _dinvse
B _wait
/*
* enable mmu and high vectors
*/
TEXT mmuenable(SB), 1, $-4
MFCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
ORR $CpCmmu, R0
MTCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
BARRIERS
RET
TEXT mmudisable(SB), 1, $-4
MFCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
BIC $CpCmmu, R0
MTCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
BARRIERS
RET
/*
* If one of these MCR instructions crashes or hangs the machine,
* check your Level 1 page table (at TTB) closely.
*/
TEXT mmuinvalidate(SB), $-4 /* invalidate all */
MOVW CPSR, R2
CPSID /* interrupts off */
BARRIERS
MTCP CpSC, 0, PC, C(CpTLB), C(CpTLBinvu), CpTLBinv
BARRIERS
MOVW R2, CPSR /* interrupts restored */
RET
TEXT mmuinvalidateaddr(SB), $-4 /* invalidate single entry */
MTCP CpSC, 0, R0, C(CpTLB), C(CpTLBinvu), CpTLBinvse
BARRIERS
RET
TEXT cpidget(SB), 1, $-4 /* main ID */
MFCP CpSC, 0, R0, C(CpID), C(CpIDidct), CpIDid
RET
TEXT cpctget(SB), 1, $-4 /* cache type */
MFCP CpSC, 0, R0, C(CpID), C(CpIDidct), CpIDct
RET
TEXT controlget(SB), 1, $-4 /* system control (sctlr) */
MFCP CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl
RET
TEXT ttbget(SB), 1, $-4 /* translation table base */
MFCP CpSC, 0, R0, C(CpTTB), C(0), CpTTB0
RET
TEXT ttbput(SB), 1, $-4 /* translation table base */
MOVW CPSR, R2
CPSID
MOVW R0, R1
BARRIERS /* finish prior accesses before changing ttb */
MTCP CpSC, 0, R1, C(CpTTB), C(0), CpTTB0
MTCP CpSC, 0, R1, C(CpTTB), C(0), CpTTB1 /* non-secure too */
MOVW $0, R0
MTCP CpSC, 0, R0, C(CpTTB), C(0), CpTTBctl
BARRIERS
MOVW R2, CPSR
RET
TEXT dacget(SB), 1, $-4 /* domain access control */
MFCP CpSC, 0, R0, C(CpDAC), C(0)
RET
TEXT dacput(SB), 1, $-4 /* domain access control */
MOVW R0, R1
BARRIERS
MTCP CpSC, 0, R1, C(CpDAC), C(0)
ISB
RET
TEXT fsrget(SB), 1, $-4 /* fault status */
MFCP CpSC, 0, R0, C(CpFSR), C(0), CpDFSR
RET
TEXT farget(SB), 1, $-4 /* fault address */
MFCP CpSC, 0, R0, C(CpFAR), C(0), CpDFAR
RET
TEXT getpsr(SB), 1, $-4
MOVW CPSR, R0
RET
TEXT getscr(SB), 1, $-4 /* secure configuration */
MFCP CpSC, 0, R0, C(CpCONTROL), C(CpCONTROLscr), CpSCRscr
RET
TEXT pidget(SB), 1, $-4 /* address translation pid */
MFCP CpSC, 0, R0, C(CpPID), C(0x0)
RET
TEXT pidput(SB), 1, $-4 /* address translation pid */
MTCP CpSC, 0, R0, C(CpPID), C(0), 0 /* pid, v7a deprecated */
MTCP CpSC, 0, R0, C(CpPID), C(0), 1 /* context id, errata 754322 */
ISB
RET
/*
* access to yet more coprocessor registers
*/
TEXT getauxctl(SB), 1, $-4 /* get cortex-a9 aux. ctl. */
MFCP CpSC, 0, R0, C(CpCONTROL), C(0), CpAuxctl
RET
TEXT putauxctl(SB), 1, $-4 /* put cortex-a9 aux. ctl. */
BARRIERS
MTCP CpSC, 0, R0, C(CpCONTROL), C(0), CpAuxctl
BARRIERS
RET
TEXT getclvlid(SB), 1, $-4
MFCP CpSC, CpIDcsize, R0, C(CpID), C(CpIDidct), CpIDclvlid
RET
TEXT getcyc(SB), 1, $-4
MFCP CpSC, 0, R0, C(CpCLD), C(CpCLDcyc), 0
RET
TEXT getdebug(SB), 1, $-4 /* get cortex-a9 debug enable register */
MFCP CpSC, 0, R0, C(1), C(1), 1
RET
TEXT getpc(SB), 1, $-4
MOVW PC, R0
RET
TEXT getsb(SB), 1, $-4
MOVW R12, R0
RET
TEXT setsp(SB), 1, $-4
MOVW R0, SP
RET
TEXT splhi(SB), 1, $-4
MOVW CPSR, R0 /* return old CPSR */
CPSID /* turn off interrupts */
CMP.S $0, R(MACH)
MOVW.NE R14, 4(R(MACH)) /* save caller pc in m->splpc */
RET
TEXT spllo(SB), 1, $-4 /* start marker for devkprof.c */
MOVW CPSR, R0 /* return old CPSR */
MOVW $0, R1
CMP.S R1, R(MACH)
MOVW.NE R1, 4(R(MACH)) /* clear m->splpc */
CPSIE
RET
TEXT splx(SB), 1, $-4
MOVW CPSR, R3 /* must return old CPSR */
CPSID
CMP.S $0, R(MACH)
MOVW.NE R14, 4(R(MACH)) /* save caller pc in m->splpc */
MOVW R0, CPSR /* reset interrupt level */
MOVW R3, R0 /* must return old CPSR */
RET
TEXT spldone(SB), 1, $0 /* end marker for devkprof.c */
RET
TEXT islo(SB), 1, $-4
MOVW CPSR, R0
AND $(PsrDirq), R0
EOR $(PsrDirq), R0
RET
TEXT clz(SB), $-4
CLZ(0, 0) /* 0 is R0 */
RET
TEXT setlabel(SB), 1, $-4
MOVW SP, 0(R0)
MOVW R14, 4(R0) /* pc */
MOVW $0, R0
RET
TEXT gotolabel(SB), 1, $-4
MOVW 0(R0), SP
MOVW 4(R0), R14 /* pc */
MOVW $1, R0
RET
TEXT getcallerpc(SB), 1, $-4
MOVW 0(SP), R0
RET
TEXT wfi(SB), $-4
MOVW CPSR, R1
/*
* an interrupt should break us out of wfi. masking interrupts
* slows interrupt response slightly but prevents recursion.
*/
// CPSIE
CPSID
BARRIERS
WFI
MOVW R1, CPSR
RET
TEXT coherence(SB), $-4
BARRIERS
RET
GLOBL cpus_proceed+0(SB), $4
#include "cache.v7.s"
TEXT cas(SB),0,$12
TEXT cmpswap(SB),0,$12 /* r0 holds p */
MOVW ov+4(FP), R1
MOVW nv+8(FP), R2
spin:
/* LDREX 0(R0),R3 */
LDREX(0,3)
CMP.S R3, R1
BNE fail
/* STREX 0(R0),R2,R4 */
STREX(0,2,4)
CMP.S $0, R4
BNE spin
MOVW $1, R0
DMB
RET
fail:
MOVW $0, R0
RET
TEXT tas(SB), $-4 /* _tas(ulong *) */
TEXT _tas(SB), $-4
/* returns old (R0) after modifying (R0) */
MOVW R0,R5
DMB
MOVW $1,R2 /* new value of (R0) */
MOVW $MAXSC, R8
tas1:
LDREX(5,7) /* LDREX 0(R5),R7 */
CMP.S $0, R7 /* old value non-zero (lock taken)? */
BNE lockbusy /* we lose */
SUB.S $1, R8
BEQ lockloop2
STREX(2,5,4) /* STREX R2,(R5),R4 */
CMP.S $0, R4
BNE tas1 /* strex failed? try again */
DMB
B tas0
lockloop2:
PUTC('?')
PUTC('l')
PUTC('t')
BL abort(SB)
lockbusy:
CLREX
tas0:
MOVW R7, R0 /* return old value */
RET