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authorSam Ravnborg <sam@ravnborg.org>2012-05-25 21:20:06 +0000
committerDavid S. Miller <davem@davemloft.net>2012-05-27 23:52:41 -0700
commit7b372d6582ca3bf41a1af9f168f3a852f3d7b21d (patch)
tree3a3269b976d713dd728b119e388f8f262c533138 /arch/sparc/kernel/head_32.S
parentec24158eac0ae2786ebf1e0afa8f3664891319ba (diff)
sparc32: implement proper LEON support in head_32 (before highmem)
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>
Diffstat (limited to 'arch/sparc/kernel/head_32.S')
-rw-r--r--arch/sparc/kernel/head_32.S58
1 files changed, 47 insertions, 11 deletions
diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S
index 693fb080f933..5a418d32d94c 100644
--- a/arch/sparc/kernel/head_32.S
+++ b/arch/sparc/kernel/head_32.S
@@ -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:
+ /* 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
+
+ /* Sanity-check, is MMU enabled */
lda [%g0] ASI_M_MMUREGS, %g1
andcc %g1, 1, %g0
- be halt_sun4_or_sun4c
+ be halt_notsup
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
+ /* 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