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sparc32: implement proper LEON support in head_32 (before highmem)

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Use PSR to check if the CPU is LEON and jump to
LEON specific code in this case.

Added a few constants to psr.h to increase readability.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Cc: Konrad Eisele <konrad@gaisler.com>
This commit is contained in:
Sam Ravnborg 2012-05-25 21:20:06 +00:00 committed by David S. Miller
parent ec24158eac
commit 7b372d6582
2 changed files with 55 additions and 13 deletions
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6
arch/sparc/include/asm/psr.h
View file

@ -35,6 +35,12 @@
#define PSR_VERS 0x0f000000 /* cpu-version field */
#define PSR_IMPL 0xf0000000 /* cpu-implementation field */
#define PSR_IMPL_SHIFT 28
#define PSR_IMPL_SHIFTED_MASK 0xf
#define PSR_IMPL_TI 0x4
#define PSR_IMPL_LEON 0xf
#ifdef __KERNEL__
#ifndef __ASSEMBLY__

62
arch/sparc/kernel/head_32.S
View file

@ -192,7 +192,7 @@ copy_prom_done:
bne not_a_sun4
nop
halt_sun4_or_sun4c:
halt_notsup:
ld [%g7 + 0x68], %o1
set notsup, %o0
sub %o0, %l6, %o0
@ -202,18 +202,31 @@ halt_sun4_or_sun4c:
nop
not_a_sun4:
lda [%g0] ASI_M_MMUREGS, %g1
andcc %g1, 1, %g0
be halt_sun4_or_sun4c
/* It looks like this is a machine we support.
* Now find out what MMU we are dealing with
* LEON - identified by the psr.impl field
* Viking - identified by the psr.impl field
* In all other cases a sun4m srmmu.
* We check that the MMU is enabled in all cases.
*/
/* Check if this is a LEON CPU */
rd %psr, %g3
srl %g3, PSR_IMPL_SHIFT, %g3
and %g3, PSR_IMPL_SHIFTED_MASK, %g3
cmp %g3, PSR_IMPL_LEON
be leon_remap /* It is a LEON - jump */
nop
srmmu_remap:
/* First, check for a viking (TI) module. */
set 0x40000000, %g2
rd %psr, %g3
and %g2, %g3, %g3
subcc %g3, 0x0, %g0
bz srmmu_nviking
/* Sanity-check, is MMU enabled */
lda [%g0] ASI_M_MMUREGS, %g1
andcc %g1, 1, %g0
be halt_notsup
nop
/* Check for a viking (TI) module. */
cmp %g3, PSR_IMPL_TI
bne srmmu_not_viking
nop
/* Figure out what kind of viking we are on.
@ -228,7 +241,7 @@ srmmu_remap:
lda [%g0] ASI_M_MMUREGS, %g3 ! peek in the control reg
and %g2, %g3, %g3
subcc %g3, 0x0, %g0
bnz srmmu_nviking ! is in mbus mode
bnz srmmu_not_viking ! is in mbus mode
nop
rd %psr, %g3 ! DO NOT TOUCH %g3
@ -293,12 +306,12 @@ srmmu_remap:
b go_to_highmem
nop
srmmu_not_viking:
/* This works on viking's in Mbus mode and all
* other MBUS modules. It is virtually the same as
* the above madness sans turning traps off and flipping
* the AC bit.
*/
srmmu_nviking:
set AC_M_CTPR, %g1
lda [%g1] ASI_M_MMUREGS, %g1 ! get ctx table ptr
sll %g1, 0x4, %g1 ! make physical addr
@ -313,6 +326,29 @@ srmmu_nviking:
nop ! wheee....
leon_remap:
/* Sanity-check, is MMU enabled */
lda [%g0] ASI_LEON_MMUREGS, %g1
andcc %g1, 1, %g0
be halt_notsup
nop
/* Same code as in the srmmu_not_viking case,
* with the LEON ASI for mmuregs
*/
set AC_M_CTPR, %g1
lda [%g1] ASI_LEON_MMUREGS, %g1 ! get ctx table ptr
sll %g1, 0x4, %g1 ! make physical addr
lda [%g1] ASI_M_BYPASS, %g1 ! ptr to level 1 pg_table
srl %g1, 0x4, %g1
sll %g1, 0x8, %g1 ! make phys addr for l1 tbl
lda [%g1] ASI_M_BYPASS, %g2 ! get level1 entry for 0x0
add %g1, KERNBASE >> (SRMMU_PGDIR_SHIFT - 2), %g3
sta %g2, [%g3] ASI_M_BYPASS ! place at KERNBASE entry
b go_to_highmem
nop ! wheee....
/* Now do a non-relative jump so that PC is in high-memory */
go_to_highmem:
set execute_in_high_mem, %g1