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authorNicholas Piggin <npiggin@gmail.com>2019-09-03 01:29:31 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2019-09-05 14:22:41 +1000
commit2275d7b5754a573ffb2ca9e40bd0546eeb986696 (patch)
treebade285c88d930fa71326efe75fcb7f994d31eb5 /drivers/misc/cxl
parent7d805accbec57a151bd0dd305a1109feebdfd4a4 (diff)
powerpc/64s/radix: introduce options to disable use of the tlbie instruction
Introduce two options to control the use of the tlbie instruction. A boot time option which completely disables the kernel using the instruction, this is currently incompatible with HASH MMU, KVM, and coherent accelerators. And a debugfs option can be switched at runtime and avoids using tlbie for invalidating CPU TLBs for normal process and kernel address mappings. Coherent accelerators are still managed with tlbie, as will KVM partition scope translations. Cross-CPU TLB flushing is implemented with IPIs and tlbiel. This is a basic implementation which does not attempt to make any optimisation beyond the tlbie implementation. This is useful for performance testing among other things. For example in certain situations on large systems, using IPIs may be faster than tlbie as they can be directed rather than broadcast. Later we may also take advantage of the IPIs to do more interesting things such as trim the mm cpumask more aggressively. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190902152931.17840-7-npiggin@gmail.com
Diffstat (limited to 'drivers/misc/cxl')
-rw-r--r--drivers/misc/cxl/main.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index 482a2c1b340a..43b312d06e3e 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -18,6 +18,7 @@
#include <linux/sched/task.h>
#include <asm/cputable.h>
+#include <asm/mmu.h>
#include <misc/cxl-base.h>
#include "cxl.h"
@@ -315,6 +316,9 @@ static int __init init_cxl(void)
{
int rc = 0;
+ if (!tlbie_capable)
+ return -EINVAL;
+
if ((rc = cxl_file_init()))
return rc;