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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2016-07-13 15:05:31 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2016-07-17 16:42:55 +1000
commitb275bfb2696387be216db5b7372ee9dcf3f05b80 (patch)
tree86e47bb902cc99d0da9273625188cce36989e728 /arch/powerpc/kernel/prom.c
parent912cc87a654d3d30f5da6220489a97a5beb7d313 (diff)
powerpc/mm/radix: Add a kernel command line to disable radix
This patch adds the kernel command line disable_radix which disable the radix MMU mode even if firmware indicates radix support via ibm,pa-features device tree node. This helps in testing different MMU mode easily. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/prom.c')
-rw-r--r--arch/powerpc/kernel/prom.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 48434be99a07..7a01113d525c 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -646,6 +646,14 @@ static void __init early_reserve_mem(void)
#endif
}
+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 early_init_devtree(void *params)
{
phys_addr_t limit;
@@ -735,6 +743,11 @@ void __init early_init_devtree(void *params)
*/
spinning_secondaries = boot_cpu_count - 1;
#endif
+ /*
+ * now fixup radix MMU mode based on kernel command line
+ */
+ if (disable_radix)
+ cur_cpu_spec->mmu_features &= ~MMU_FTR_RADIX;
#ifdef CONFIG_PPC_POWERNV
/* Scan and build the list of machine check recoverable ranges */