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powerpc: Remove tlb batching hack for nighthawk 

In hpte_init_native() we call tlb_batching_enabled() to decide if we
should setup ppc_md.flush_hash_range.

tlb_batching_enabled() checks the _unflattened_ device tree, to see
if we are running on a nighthawk.

Since commit a223535 ("dont allow pSeries_probe to succeed without
initialising MMU", Dec 2006), hpte_init_native() has been called from
pSeries_probe() - at which point we have not yet unflattened the
device tree.

This means tlb_batching_enabled() will always return true, so the hack
has effectively been disabled since Dec 2006. Ergo, I think we can
drop it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Michael Ellerman 2012-09-20 22:08:28 +00:00 committed by Benjamin Herrenschmidt
parent 466921c5a4
commit 8e166991c0
1 changed files with 1 additions and 25 deletions
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26
arch/powerpc/mm/hash_native_64.c
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@ -569,29 +569,6 @@ static void native_flush_hash_range(unsigned long number, int local)
local_irq_restore(flags);
}
#ifdef CONFIG_PPC_PSERIES
/* Disable TLB batching on nighthawk */
static inline int tlb_batching_enabled(void)
{
struct device_node *root = of_find_node_by_path("/");
int enabled = 1;
if (root) {
const char *model = of_get_property(root, "model", NULL);
if (model && !strcmp(model, "IBM,9076-N81"))
enabled = 0;
of_node_put(root);
}
return enabled;
}
#else
static inline int tlb_batching_enabled(void)
{
return 1;
}
#endif
void __init hpte_init_native(void)
{
ppc_md.hpte_invalidate = native_hpte_invalidate;
@ -600,6 +577,5 @@ void __init hpte_init_native(void)
ppc_md.hpte_insert = native_hpte_insert;
ppc_md.hpte_remove = native_hpte_remove;
ppc_md.hpte_clear_all = native_hpte_clear;
if (tlb_batching_enabled())
ppc_md.flush_hash_range = native_flush_hash_range;
ppc_md.flush_hash_range = native_flush_hash_range;
}