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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2007 Advanced Micro Devices, Inc.
* Copyright (C) 2010 Nils Jacobs
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc.
*/
#define GX2_STACK_BASE CONFIG_DCACHE_RAM_BASE /* this is where the DCache will be mapped and be used as stack, It would be cool if it was the same base as coreboot normal stack */
#define GX2_STACK_END GX2_STACK_BASE+(CONFIG_DCACHE_RAM_SIZE-1)
#define GX2_NUM_CACHELINES 0x080 /* there are 128lines per way */
#define GX2_CACHELINE_SIZE 0x020 /* there are 32bytes per line */
#define GX2_CACHEWAY_SIZE (GX2_NUM_CACHELINES * GX2_CACHELINE_SIZE)
#define CR0_CD 0x40000000 /* bit 30 = Cache Disable */
#define CR0_NW 0x20000000 /* bit 29 = Not Write Through */
#include <cpu/amd/gx2def.h>
#include <cpu/x86/post_code.h>
/*
* DCacheSetup
*
* Setup data cache for use as RAM for a stack.
*
* Max. size data cache =0x4000 (16KB)
*/
DCacheSetup:
/* Save the BIST result */
movl %eax, %ebx
invd
/* set cache properties */
movl $CPU_RCONF_DEFAULT, %ecx
rdmsr
movl $0x010010000, %eax /*1MB system memory in write back 1|00100|00 */
wrmsr
/* in GX2 DCDIS is set after POR which disables the cache..., clear this bit */
movl $CPU_DM_CONFIG0, %ecx
rdmsr
andl $(~(DM_CONFIG0_LOWER_DCDIS_SET)), %eax /* TODO: make consistent with i$ init, either whole reg = 0, or just this bit... */
wrmsr
/* Get cleaned up. */
xorl %edi, %edi
xorl %esi, %esi
xorl %ebp, %ebp
/* DCache Ways0 through Ways3 will be tagged for GX2_STACK_BASE + CONFIG_DCACHE_RAM_SIZE for holding stack */
/* remember, there is NO stack yet... */
/* Tell cache we want to fill WAY 0 starting at the top */
xorl %edx, %edx
xorl %eax, %eax
movl $CPU_DC_INDEX, %ecx
wrmsr
/* startaddress for tag of Way0: ebp will hold the incrementing address. dont destroy! */
movl $GX2_STACK_BASE, %ebp /* init to start address */
orl $1, %ebp /* set valid bit and tag for this Way (B[31:12] : Cache tag value for line/way curr. selected by CPU_DC_INDEX */
/* start tag Ways 0 with 128 lines with 32bytes each: edi will hold the line counter. dont destroy! */
movl $GX2_NUM_CACHELINES, %edi
DCacheSetupFillWay:
/* fill with dummy data: zero it so we can tell it from PCI memory space (returns FFs). */
/* We will now store a line (32 bytes = 4 x 8bytes = 4 quadWords) */
movw $0x04, %si
xorl %edx, %edx
xorl %eax, %eax
movl $CPU_DC_DATA, %ecx
DCacheSetup_quadWordLoop:
wrmsr
decw %si
jnz DCacheSetup_quadWordLoop
/* Set the tag for this line,need to do this for every new cache line to validate it! */
/* accessing CPU_DC_TAG_I makes the LINE field in CPU_DC_INDEX increment and thus cont. in the next cache line... */
xorl %edx, %edx
movl %ebp, %eax
movl $CPU_DC_TAG, %ecx
wrmsr
/* switch to next line */
/* lines are in Bits8:2 */
/* when index is crossing 0x7F -> 0x80 writing a RSVD bit as 0x80 is not a valid CL anymore! */
movl $CPU_DC_INDEX, %ecx
rdmsr
addl $0x04, %eax /* inc DC_LINE. TODO: prob. would be more elegant to calc. this from counter var edi... */
wrmsr
decl %edi
jnz DCacheSetupFillWay
/* 1 Way has been filled, forward start address for next Way, terminate if we have reached end of desired address range */
addl $GX2_CACHEWAY_SIZE, %ebp
cmpl $GX2_STACK_END, %ebp
jge leave_DCacheSetup
movl $GX2_NUM_CACHELINES, %edi
/* switch to next way */
movl $CPU_DC_INDEX, %ecx
rdmsr
addl $0x01, %eax
andl $0xFFFFFE03, %eax /* lets be sure: reset line index Bits8:2 */
wrmsr
jmp DCacheSetupFillWay
leave_DCacheSetup:
xorl %edi, %edi
xorl %esi, %esi
xorl %ebp, %ebp
/* Disable the cache, but ... DO NOT INVALIDATE the tags. */
/* Memory reads and writes will all hit in the cache. */
/* Cache updates and memory write-backs will not occur ! */
movl %cr0, %eax
orl $(CR0_CD + CR0_NW), %eax /* set the CD and NW bits */
movl %eax, %cr0
/* Now point sp to the cached stack. */
/* The stack will be fully functional at this location. No system memory is required at all ! */
/* set up the stack pointer */
movl $GX2_STACK_END, %eax
movl %eax, %esp
/* test the stack*/
movl $0x0F0F05A5A, %edx
pushl %edx
popl %ecx
cmpl %ecx, %edx
je DCacheSetupGood
post_code(0xc5)
DCacheSetupBad:
hlt /* issues */
jmp DCacheSetupBad
DCacheSetupGood:
/* Go do early init and memory setup */
/* Restore the BIST result */
movl %ebx, %eax
movl %esp, %ebp
pushl %eax
post_code(0x23)
/* Call romstage.c main function */
call main
done_cache_as_ram_main:
/* We now run over the stack-in-cache, copying it back to itself to invalidate the cache */
push %edi
mov $(CONFIG_DCACHE_RAM_SIZE/4),%ecx
push %esi
mov $(CONFIG_DCACHE_RAM_BASE),%edi
mov %edi,%esi
cld
rep movsl %ds:(%esi),%es:(%edi)
pop %esi
pop %edi
/* Clear the cache out to ram */
wbinvd
/* re-enable the cache */
movl %cr0, %eax
xorl $(CR0_CD + CR0_NW), %eax /* clear the CD and NW bits */
movl %eax, %cr0
__main:
post_code(POST_PREPARE_RAMSTAGE)
/* TODO For suspend/resume the cache will have to live between
* CONFIG_RAMBASE and CONFIG_RAMTOP
*/
cld /* clear direction flag */
/* copy coreboot from it's initial load location to
* the location it is compiled to run at.
* Normally this is copying from FLASH ROM to RAM.
*/
call copy_and_run
.Lhlt:
post_code(POST_DEAD_CODE)
hlt
jmp .Lhlt
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