When we never get around to seeing an HEA ethernet adapter, there's
no point in restricting ourselves to 4k IO page size.
This speeds up IO maps when CONFIG_IBMEBUS is disabled.
Signed-off-by: Alexander Graf <ag...@suse.de>
---
arch/powerpc/mm/hash_utils_64.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index d766d6e..c0ef976 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -445,6 +445,20 @@ static void mmu_psize_set_default_penc(void)
mmu_psize_defs[bpsize].penc[apsize] = -1;
}
+static bool might_have_hea(void)
+{
+ /*
+ * The HEA ethernet adapter requires awareness of the
+ * GX bus. Without that awareness we can easily assume
+ * we will never see an HEA ethernet device.
+ */
+#ifdef CONFIG_IBMEBUS
+ return true;
+#else
+ return false;
+#endif
+}
+
static void __init htab_init_page_sizes(void)
{
int rc;
@@ -499,10 +513,11 @@ static void __init htab_init_page_sizes(void)
mmu_linear_psize = MMU_PAGE_64K;
if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
/*
- * Don't use 64k pages for ioremap on pSeries, since
- * that would stop us accessing the HEA ethernet.
+ * When running on pSeries using 64k pages for ioremap
+ * would stop us accessing the HEA ethernet. So if we
+ * have the chance of ever seeing one, stay at 4k.
*/
- if (!machine_is(pseries))
+ if (!might_have_hea() || !machine_is(pseries))
mmu_io_psize = MMU_PAGE_64K;
} else
mmu_ci_restrictions = 1;
--
1.8.1.4
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