| Message ID | 1337717443-11904-2-git-send-email-sam@ravnborg.org |
|---|---|
| State | RFC |
| Delegated to: | David Miller |
| Headers | show |
From: Sam Ravnborg <sam@ravnborg.org> Date: Tue, 22 May 2012 22:10:40 +0200 > Use PSR to check if the PCU is LEON and jump to ^^^ "CPU" :-) > + /* Check if this is a LEON CPU */ > + rd %psr, %g3 > + set PSR_IMPL, %g2 > + and %g2, %g3, %g3 > + srl %g3, PSR_IMPL_SHIFT, %g3 > + cmp %g3, PSR_IMPL_LEON I would code this like: rd %psr, %g3 srl %g3, PSR_IMPL_SHIFT, %g3 and %g3, 0xf /* PST_IMPL_WHATEVER_MASK */, %g3 cmp %g3, PSR_IMPL_LEON > + /* Check for a viking (TI) module. */ > + cmp %g3, PSR_IMPL_TEXAS > + bne srmmu_not_viking > nop PSR_IMPL_TI is probably a better name fo this macro. > @@ -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_sun4_or_sun4c > + nop Checking that the MMU is disabled is correct, but branching to the sun4c-not-supported error message is probably not. :-) Otherwise looks OK. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, May 22, 2012 at 04:23:10PM -0400, David Miller wrote: > From: Sam Ravnborg <sam@ravnborg.org> > Date: Tue, 22 May 2012 22:10:40 +0200 > > > Use PSR to check if the PCU is LEON and jump to > ^^^ > > "CPU" :-) > > > + /* Check if this is a LEON CPU */ > > + rd %psr, %g3 > > + set PSR_IMPL, %g2 > > + and %g2, %g3, %g3 > > + srl %g3, PSR_IMPL_SHIFT, %g3 > > + cmp %g3, PSR_IMPL_LEON > > I would code this like: > > rd %psr, %g3 > srl %g3, PSR_IMPL_SHIFT, %g3 > and %g3, 0xf /* PST_IMPL_WHATEVER_MASK */, %g3 > cmp %g3, PSR_IMPL_LEON > > > > + /* Check for a viking (TI) module. */ > > + cmp %g3, PSR_IMPL_TEXAS > > + bne srmmu_not_viking > > nop > > PSR_IMPL_TI is probably a better name fo this macro. > > > @@ -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_sun4_or_sun4c > > + nop > > Checking that the MMU is disabled is correct, but branching > to the sun4c-not-supported error message is probably not. :-) I did not like it either - but this was a straight copy from the old code with proper replacement of the MMUREGS. I actually considered to just drop it. I will rephrase the text in a separate commit. > > Otherwise looks OK. > Thanks for the quick feedback! I will address it all and get back. Will take a couple of days as weather is too good to do serious coding ;-) Sam -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/sparc/include/asm/psr.h b/arch/sparc/include/asm/psr.h index b8c0e5f..eae4a9f 100644 --- a/arch/sparc/include/asm/psr.h +++ b/arch/sparc/include/asm/psr.h @@ -35,6 +35,11 @@ #define PSR_VERS 0x0f000000 /* cpu-version field */ #define PSR_IMPL 0xf0000000 /* cpu-implementation field */ +#define PSR_IMPL_SHIFT 28 + +#define PSR_IMPL_TEXAS 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 4710aaf..1be5b62 100644 --- a/arch/sparc/kernel/head_32.S +++ b/arch/sparc/kernel/head_32.S @@ -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 + */ + + /* Check if this is a LEON CPU */ + rd %psr, %g3 + set PSR_IMPL, %g2 + and %g2, %g3, %g3 + srl %g3, PSR_IMPL_SHIFT, %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 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_TEXAS + 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_sun4_or_sun4c + 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
Use PSR to check if the PCU 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> --- arch/sparc/include/asm/psr.h | 5 ++++ arch/sparc/kernel/head_32.S | 54 +++++++++++++++++++++++++++++++++++------- 2 files changed, 50 insertions(+), 9 deletions(-)