diff options
| author | Sam Ravnborg <sam@ravnborg.org> | 2012-05-25 21:20:06 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-05-27 23:52:41 -0700 |
| commit | 7b372d6582ca3bf41a1af9f168f3a852f3d7b21d (patch) | |
| tree | 3a3269b976d713dd728b119e388f8f262c533138 /arch/sparc | |
| parent | ec24158eac0ae2786ebf1e0afa8f3664891319ba (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')
| -rw-r--r-- | arch/sparc/include/asm/psr.h | 6 | ||||
| -rw-r--r-- | arch/sparc/kernel/head_32.S | 58 |
2 files changed, 53 insertions, 11 deletions
diff --git a/arch/sparc/include/asm/psr.h b/arch/sparc/include/asm/psr.h index b8c0e5f0a66..c02c735d4eb 100644 --- a/arch/sparc/include/asm/psr.h +++ b/arch/sparc/include/asm/psr.h @@ -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__ diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S index 693fb080f93..5a418d32d94 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 |