powerpc/mm: Move disable_radix handling into mmu_early_init_devtree()

Move the handling of the disable_radix command line argument into the
newly created mmu_early_init_devtree().

It's an MMU option so it's preferable to have it in an mm related file,
and it also means platforms that don't support radix don't have to carry
the code.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index d0fb33ac3db2..0d51e6e25db5 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -413,7 +413,18 @@ EXPORT_SYMBOL_GPL(realmode_pfn_to_page);
 #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */
 
 #ifdef CONFIG_PPC_STD_MMU_64
+static bool disable_radix;
+static int __init parse_disable_radix(char *p)
+{
+        disable_radix = true;
+        return 0;
+}
+early_param("disable_radix", parse_disable_radix);
+
 void __init mmu_early_init_devtree(void)
 {
+        /* Disable radix mode based on kernel command line. */
+        if (disable_radix)
+                cur_cpu_spec->mmu_features &= ~MMU_FTR_RADIX;
 }
 #endif /* CONFIG_PPC_STD_MMU_64 */