linux_dsm_epyc7002/arch/sparc64/kernel/ktlb.S
David S. Miller 517af33237 [SPARC64]: Access TSB with physical addresses when possible.
This way we don't need to lock the TSB into the TLB.
The trick is that every TSB load/store is registered into
a special instruction patch section.  The default uses
virtual addresses, and the patch instructions use physical
address load/stores.

We can't do this on all chips because only cheetah+ and later
have the physical variant of the atomic quad load.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:32 -08:00

174 lines
3.7 KiB
ArmAsm

/* arch/sparc64/kernel/ktlb.S: Kernel mapping TLB miss handling.
*
* Copyright (C) 1995, 1997, 2005 David S. Miller <davem@davemloft.net>
* Copyright (C) 1996 Eddie C. Dost (ecd@brainaid.de)
* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
* Copyright (C) 1996,98,99 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/config.h>
#include <asm/head.h>
#include <asm/asi.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tsb.h>
.text
.align 32
.globl kvmap_itlb
kvmap_itlb:
/* g6: TAG TARGET */
mov TLB_TAG_ACCESS, %g4
ldxa [%g4] ASI_IMMU, %g4
kvmap_itlb_nonlinear:
/* Catch kernel NULL pointer calls. */
sethi %hi(PAGE_SIZE), %g5
cmp %g4, %g5
bleu,pn %xcc, kvmap_dtlb_longpath
nop
KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_itlb_load)
kvmap_itlb_tsb_miss:
sethi %hi(LOW_OBP_ADDRESS), %g5
cmp %g4, %g5
blu,pn %xcc, kvmap_itlb_vmalloc_addr
mov 0x1, %g5
sllx %g5, 32, %g5
cmp %g4, %g5
blu,pn %xcc, kvmap_itlb_obp
nop
kvmap_itlb_vmalloc_addr:
KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath)
KTSB_LOCK_TAG(%g1, %g2, %g4)
/* Load and check PTE. */
ldxa [%g5] ASI_PHYS_USE_EC, %g5
brgez,a,pn %g5, kvmap_itlb_longpath
KTSB_STORE(%g1, %g0)
KTSB_WRITE(%g1, %g5, %g6)
/* fallthrough to TLB load */
kvmap_itlb_load:
stxa %g5, [%g0] ASI_ITLB_DATA_IN ! Reload TLB
retry
kvmap_itlb_longpath:
rdpr %pstate, %g5
wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
rdpr %tpc, %g5
ba,pt %xcc, sparc64_realfault_common
mov FAULT_CODE_ITLB, %g4
kvmap_itlb_obp:
OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath)
KTSB_LOCK_TAG(%g1, %g2, %g4)
KTSB_WRITE(%g1, %g5, %g6)
ba,pt %xcc, kvmap_itlb_load
nop
kvmap_dtlb_obp:
OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath)
KTSB_LOCK_TAG(%g1, %g2, %g4)
KTSB_WRITE(%g1, %g5, %g6)
ba,pt %xcc, kvmap_dtlb_load
nop
.align 32
.globl kvmap_dtlb
kvmap_dtlb:
/* %g6: TAG TARGET */
mov TLB_TAG_ACCESS, %g4
ldxa [%g4] ASI_DMMU, %g4
brgez,pn %g4, kvmap_dtlb_nonlinear
nop
#define KERN_HIGHBITS ((_PAGE_VALID|_PAGE_SZ4MB)^0xfffff80000000000)
#define KERN_LOWBITS (_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W)
sethi %uhi(KERN_HIGHBITS), %g2
or %g2, %ulo(KERN_HIGHBITS), %g2
sllx %g2, 32, %g2
or %g2, KERN_LOWBITS, %g2
#undef KERN_HIGHBITS
#undef KERN_LOWBITS
.globl kvmap_linear_patch
kvmap_linear_patch:
ba,pt %xcc, kvmap_dtlb_load
xor %g2, %g4, %g5
kvmap_dtlb_vmalloc_addr:
KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath)
KTSB_LOCK_TAG(%g1, %g2, %g4)
/* Load and check PTE. */
ldxa [%g5] ASI_PHYS_USE_EC, %g5
brgez,a,pn %g5, kvmap_dtlb_longpath
KTSB_STORE(%g1, %g0)
KTSB_WRITE(%g1, %g5, %g6)
/* fallthrough to TLB load */
kvmap_dtlb_load:
stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB
retry
kvmap_dtlb_nonlinear:
/* Catch kernel NULL pointer derefs. */
sethi %hi(PAGE_SIZE), %g5
cmp %g4, %g5
bleu,pn %xcc, kvmap_dtlb_longpath
nop
KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
kvmap_dtlb_tsbmiss:
sethi %hi(MODULES_VADDR), %g5
cmp %g4, %g5
blu,pn %xcc, kvmap_dtlb_longpath
mov (VMALLOC_END >> 24), %g5
sllx %g5, 24, %g5
cmp %g4, %g5
bgeu,pn %xcc, kvmap_dtlb_longpath
nop
kvmap_check_obp:
sethi %hi(LOW_OBP_ADDRESS), %g5
cmp %g4, %g5
blu,pn %xcc, kvmap_dtlb_vmalloc_addr
mov 0x1, %g5
sllx %g5, 32, %g5
cmp %g4, %g5
blu,pn %xcc, kvmap_dtlb_obp
nop
ba,pt %xcc, kvmap_dtlb_vmalloc_addr
nop
kvmap_dtlb_longpath:
rdpr %pstate, %g5
wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
rdpr %tl, %g4
cmp %g4, 1
mov TLB_TAG_ACCESS, %g4
ldxa [%g4] ASI_DMMU, %g5
be,pt %xcc, sparc64_realfault_common
mov FAULT_CODE_DTLB, %g4
ba,pt %xcc, winfix_trampoline
nop