linux/arch/ppc/platforms/pmac_sleep.S
Benjamin Herrenschmidt f1c55dea0b [PATCH] ppc32: Fix errata for some G3 CPUs
Some G3 CPUs can crash in funny way if a store from an FPU register
instruction is executed on a register that has never been initialized since
power on.  This patch fixes it by making sure all FP registers have been
properly initialized at kernel boot and when waking from sleep.  It also makes
the code that decides wether HID0_BTIC and HID0_DPM are allowed on a given CPU
smarter (it can actually _clear_ them now if they are not allowed instead of
just setting them when they are allowed in case the firmware got them wrong)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:40 -07:00

395 lines
8.0 KiB
ArmAsm

/*
* This file contains sleep low-level functions for PowerBook G3.
* Copyright (C) 1999 Benjamin Herrenschmidt (benh@kernel.crashing.org)
* and Paul Mackerras (paulus@samba.org).
*
* 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 <linux/config.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/ppc_asm.h>
#include <asm/cputable.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/offsets.h>
#define MAGIC 0x4c617273 /* 'Lars' */
/*
* Structure for storing CPU registers on the stack.
*/
#define SL_SP 0
#define SL_PC 4
#define SL_MSR 8
#define SL_SDR1 0xc
#define SL_SPRG0 0x10 /* 4 sprg's */
#define SL_DBAT0 0x20
#define SL_IBAT0 0x28
#define SL_DBAT1 0x30
#define SL_IBAT1 0x38
#define SL_DBAT2 0x40
#define SL_IBAT2 0x48
#define SL_DBAT3 0x50
#define SL_IBAT3 0x58
#define SL_TB 0x60
#define SL_R2 0x68
#define SL_CR 0x6c
#define SL_R12 0x70 /* r12 to r31 */
#define SL_SIZE (SL_R12 + 80)
.section .text
.align 5
#if defined(CONFIG_PMAC_PBOOK) || defined(CONFIG_CPU_FREQ_PMAC)
/* This gets called by via-pmu.c late during the sleep process.
* The PMU was already send the sleep command and will shut us down
* soon. We need to save all that is needed and setup the wakeup
* vector that will be called by the ROM on wakeup
*/
_GLOBAL(low_sleep_handler)
#ifndef CONFIG_6xx
blr
#else
mflr r0
stw r0,4(r1)
stwu r1,-SL_SIZE(r1)
mfcr r0
stw r0,SL_CR(r1)
stw r2,SL_R2(r1)
stmw r12,SL_R12(r1)
/* Save MSR & SDR1 */
mfmsr r4
stw r4,SL_MSR(r1)
mfsdr1 r4
stw r4,SL_SDR1(r1)
/* Get a stable timebase and save it */
1: mftbu r4
stw r4,SL_TB(r1)
mftb r5
stw r5,SL_TB+4(r1)
mftbu r3
cmpw r3,r4
bne 1b
/* Save SPRGs */
mfsprg r4,0
stw r4,SL_SPRG0(r1)
mfsprg r4,1
stw r4,SL_SPRG0+4(r1)
mfsprg r4,2
stw r4,SL_SPRG0+8(r1)
mfsprg r4,3
stw r4,SL_SPRG0+12(r1)
/* Save BATs */
mfdbatu r4,0
stw r4,SL_DBAT0(r1)
mfdbatl r4,0
stw r4,SL_DBAT0+4(r1)
mfdbatu r4,1
stw r4,SL_DBAT1(r1)
mfdbatl r4,1
stw r4,SL_DBAT1+4(r1)
mfdbatu r4,2
stw r4,SL_DBAT2(r1)
mfdbatl r4,2
stw r4,SL_DBAT2+4(r1)
mfdbatu r4,3
stw r4,SL_DBAT3(r1)
mfdbatl r4,3
stw r4,SL_DBAT3+4(r1)
mfibatu r4,0
stw r4,SL_IBAT0(r1)
mfibatl r4,0
stw r4,SL_IBAT0+4(r1)
mfibatu r4,1
stw r4,SL_IBAT1(r1)
mfibatl r4,1
stw r4,SL_IBAT1+4(r1)
mfibatu r4,2
stw r4,SL_IBAT2(r1)
mfibatl r4,2
stw r4,SL_IBAT2+4(r1)
mfibatu r4,3
stw r4,SL_IBAT3(r1)
mfibatl r4,3
stw r4,SL_IBAT3+4(r1)
/* Backup various CPU config stuffs */
bl __save_cpu_setup
/* The ROM can wake us up via 2 different vectors:
* - On wallstreet & lombard, we must write a magic
* value 'Lars' at address 4 and a pointer to a
* memory location containing the PC to resume from
* at address 0.
* - On Core99, we must store the wakeup vector at
* address 0x80 and eventually it's parameters
* at address 0x84. I've have some trouble with those
* parameters however and I no longer use them.
*/
lis r5,grackle_wake_up@ha
addi r5,r5,grackle_wake_up@l
tophys(r5,r5)
stw r5,SL_PC(r1)
lis r4,KERNELBASE@h
tophys(r5,r1)
addi r5,r5,SL_PC
lis r6,MAGIC@ha
addi r6,r6,MAGIC@l
stw r5,0(r4)
stw r6,4(r4)
/* Setup stuffs at 0x80-0x84 for Core99 */
lis r3,core99_wake_up@ha
addi r3,r3,core99_wake_up@l
tophys(r3,r3)
stw r3,0x80(r4)
stw r5,0x84(r4)
/* Store a pointer to our backup storage into
* a kernel global
*/
lis r3,sleep_storage@ha
addi r3,r3,sleep_storage@l
stw r5,0(r3)
/* Flush & disable all caches */
bl flush_disable_caches
/* Turn off data relocation. */
mfmsr r3 /* Save MSR in r7 */
rlwinm r3,r3,0,28,26 /* Turn off DR bit */
sync
mtmsr r3
isync
BEGIN_FTR_SECTION
/* Flush any pending L2 data prefetches to work around HW bug */
sync
lis r3,0xfff0
lwz r0,0(r3) /* perform cache-inhibited load to ROM */
sync /* (caches are disabled at this point) */
END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
/*
* Set the HID0 and MSR for sleep.
*/
mfspr r2,SPRN_HID0
rlwinm r2,r2,0,10,7 /* clear doze, nap */
oris r2,r2,HID0_SLEEP@h
sync
isync
mtspr SPRN_HID0,r2
sync
/* This loop puts us back to sleep in case we have a spurrious
* wakeup so that the host bridge properly stays asleep. The
* CPU will be turned off, either after a known time (about 1
* second) on wallstreet & lombard, or as soon as the CPU enters
* SLEEP mode on core99
*/
mfmsr r2
oris r2,r2,MSR_POW@h
1: sync
mtmsr r2
isync
b 1b
/*
* Here is the resume code.
*/
/*
* Core99 machines resume here
* r4 has the physical address of SL_PC(sp) (unused)
*/
_GLOBAL(core99_wake_up)
/* Make sure HID0 no longer contains any sleep bit and that data cache
* is disabled
*/
mfspr r3,SPRN_HID0
rlwinm r3,r3,0,11,7 /* clear SLEEP, NAP, DOZE bits */
rlwinm 3,r3,0,18,15 /* clear DCE, ICE */
mtspr SPRN_HID0,r3
sync
isync
/* sanitize MSR */
mfmsr r3
ori r3,r3,MSR_EE|MSR_IP
xori r3,r3,MSR_EE|MSR_IP
sync
isync
mtmsr r3
sync
isync
/* Recover sleep storage */
lis r3,sleep_storage@ha
addi r3,r3,sleep_storage@l
tophys(r3,r3)
lwz r1,0(r3)
/* Pass thru to older resume code ... */
/*
* Here is the resume code for older machines.
* r1 has the physical address of SL_PC(sp).
*/
grackle_wake_up:
/* Restore the kernel's segment registers before
* we do any r1 memory access as we are not sure they
* are in a sane state above the first 256Mb region
*/
li r0,16 /* load up segment register values */
mtctr r0 /* for context 0 */
lis r3,0x2000 /* Ku = 1, VSID = 0 */
li r4,0
3: mtsrin r3,r4
addi r3,r3,0x111 /* increment VSID */
addis r4,r4,0x1000 /* address of next segment */
bdnz 3b
sync
isync
subi r1,r1,SL_PC
/* Restore various CPU config stuffs */
bl __restore_cpu_setup
/* Make sure all FPRs have been initialized */
bl reloc_offset
bl __init_fpu_registers
/* Invalidate & enable L1 cache, we don't care about
* whatever the ROM may have tried to write to memory
*/
bl __inval_enable_L1
/* Restore the BATs, and SDR1. Then we can turn on the MMU. */
lwz r4,SL_SDR1(r1)
mtsdr1 r4
lwz r4,SL_SPRG0(r1)
mtsprg 0,r4
lwz r4,SL_SPRG0+4(r1)
mtsprg 1,r4
lwz r4,SL_SPRG0+8(r1)
mtsprg 2,r4
lwz r4,SL_SPRG0+12(r1)
mtsprg 3,r4
lwz r4,SL_DBAT0(r1)
mtdbatu 0,r4
lwz r4,SL_DBAT0+4(r1)
mtdbatl 0,r4
lwz r4,SL_DBAT1(r1)
mtdbatu 1,r4
lwz r4,SL_DBAT1+4(r1)
mtdbatl 1,r4
lwz r4,SL_DBAT2(r1)
mtdbatu 2,r4
lwz r4,SL_DBAT2+4(r1)
mtdbatl 2,r4
lwz r4,SL_DBAT3(r1)
mtdbatu 3,r4
lwz r4,SL_DBAT3+4(r1)
mtdbatl 3,r4
lwz r4,SL_IBAT0(r1)
mtibatu 0,r4
lwz r4,SL_IBAT0+4(r1)
mtibatl 0,r4
lwz r4,SL_IBAT1(r1)
mtibatu 1,r4
lwz r4,SL_IBAT1+4(r1)
mtibatl 1,r4
lwz r4,SL_IBAT2(r1)
mtibatu 2,r4
lwz r4,SL_IBAT2+4(r1)
mtibatl 2,r4
lwz r4,SL_IBAT3(r1)
mtibatu 3,r4
lwz r4,SL_IBAT3+4(r1)
mtibatl 3,r4
BEGIN_FTR_SECTION
li r4,0
mtspr SPRN_DBAT4U,r4
mtspr SPRN_DBAT4L,r4
mtspr SPRN_DBAT5U,r4
mtspr SPRN_DBAT5L,r4
mtspr SPRN_DBAT6U,r4
mtspr SPRN_DBAT6L,r4
mtspr SPRN_DBAT7U,r4
mtspr SPRN_DBAT7L,r4
mtspr SPRN_IBAT4U,r4
mtspr SPRN_IBAT4L,r4
mtspr SPRN_IBAT5U,r4
mtspr SPRN_IBAT5L,r4
mtspr SPRN_IBAT6U,r4
mtspr SPRN_IBAT6L,r4
mtspr SPRN_IBAT7U,r4
mtspr SPRN_IBAT7L,r4
END_FTR_SECTION_IFSET(CPU_FTR_HAS_HIGH_BATS)
/* Flush all TLBs */
lis r4,0x1000
1: addic. r4,r4,-0x1000
tlbie r4
blt 1b
sync
/* restore the MSR and turn on the MMU */
lwz r3,SL_MSR(r1)
bl turn_on_mmu
/* get back the stack pointer */
tovirt(r1,r1)
/* Restore TB */
li r3,0
mttbl r3
lwz r3,SL_TB(r1)
lwz r4,SL_TB+4(r1)
mttbu r3
mttbl r4
/* Restore the callee-saved registers and return */
lwz r0,SL_CR(r1)
mtcr r0
lwz r2,SL_R2(r1)
lmw r12,SL_R12(r1)
addi r1,r1,SL_SIZE
lwz r0,4(r1)
mtlr r0
blr
turn_on_mmu:
mflr r4
tovirt(r4,r4)
mtsrr0 r4
mtsrr1 r3
sync
isync
rfi
#endif /* defined(CONFIG_PMAC_PBOOK) || defined(CONFIG_CPU_FREQ) */
.section .data
.balign L1_CACHE_LINE_SIZE
sleep_storage:
.long 0
.balign L1_CACHE_LINE_SIZE, 0
#endif /* CONFIG_6xx */
.section .text