[PATCH] MIPS: Fix early CM probing

From: Paul Burton
Date: Mon Feb 08 2016 - 12:47:06 EST


Commit c014d164f21d ("MIPS: Add platform callback before initializing
the L2 cache") added a platform_early_l2_init function in order to allow
platforms to probe for the CM before L2 initialisation is performed, so
that CM GCRs are available to mips_sc_probe.

That commit actually fails to do anything useful, since it checks
mips_cm_revision to determine whether it should call mips_cm_probe but
the result of mips_cm_revision will always be 0 until mips_cm_probe has
been called. Thus the "early" mips_cm_probe call never occurs.

Fix this & drop the useless weak platform_early_l2_init function by
simply calling mips_cm_probe from setup_arch. For platforms that don't
select CONFIG_MIPS_CM this will be a no-op, and for those that do it
removes the requirement for them to call mips_cm_probe manually
(although doing so isn't harmful for now).

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---

arch/mips/kernel/setup.c | 1 +
arch/mips/mm/sc-mips.c | 10 ----------
arch/mips/mti-malta/malta-init.c | 8 --------
3 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 569a7d5..5fdaf8b 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -782,6 +782,7 @@ static inline void prefill_possible_map(void) {}
void __init setup_arch(char **cmdline_p)
{
cpu_probe();
+ mips_cm_probe();
prom_init();

setup_early_fdc_console();
diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c
index 3bd0597..2496475 100644
--- a/arch/mips/mm/sc-mips.c
+++ b/arch/mips/mm/sc-mips.c
@@ -181,10 +181,6 @@ static int __init mips_sc_probe_cm3(void)
return 1;
}

-void __weak platform_early_l2_init(void)
-{
-}
-
static inline int __init mips_sc_probe(void)
{
struct cpuinfo_mips *c = &current_cpu_data;
@@ -194,12 +190,6 @@ static inline int __init mips_sc_probe(void)
/* Mark as not present until probe completed */
c->scache.flags |= MIPS_CACHE_NOT_PRESENT;

- /*
- * Do we need some platform specific probing before
- * we configure L2?
- */
- platform_early_l2_init();
-
if (mips_cm_revision() >= CM_REV_CM3)
return mips_sc_probe_cm3();

diff --git a/arch/mips/mti-malta/malta-init.c b/arch/mips/mti-malta/malta-init.c
index 571148c..dc2c521 100644
--- a/arch/mips/mti-malta/malta-init.c
+++ b/arch/mips/mti-malta/malta-init.c
@@ -293,7 +293,6 @@ mips_pci_controller:
console_config();
#endif
/* Early detection of CMP support */
- mips_cm_probe();
mips_cpc_probe();

if (!register_cps_smp_ops())
@@ -304,10 +303,3 @@ mips_pci_controller:
return;
register_up_smp_ops();
}
-
-void platform_early_l2_init(void)
-{
- /* L2 configuration lives in the CM3 */
- if (mips_cm_revision() >= CM_REV_CM3)
- mips_cm_probe();
-}
--
2.7.0