x86: mtrr cleanup for converting continuous to discrete - auto detect v4

Loop through mtrr chunk_size and gran_size from 1M to 2G to find out
the optimal value so user does not need to add mtrr_chunk_size and
mtrr_gran_size to the kernel command line.

If optimal value is not found, print out all list to help select less
optimal value.

Add mtrr_spare_reg_nr= so user could set 2 instead of 1, if the card
need more entries.

v2: find the one with more spare entries
v3: fix hole_basek offset
v4: tight the compare between range and range_new
    loop stop with 4g

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Mika Fischer <mika.fischer@zoopnet.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f417fe33d852..9e9761504422 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1117,6 +1117,15 @@ config MTRR_SANITIZER_ENABLE_DEFAULT
         help
           Enable mtrr cleanup default value
 
+config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
+        int "MTRR cleanup spare reg num (0-7)"
+        range 0 7
+        default "1"
+        depends on MTRR_SANITIZER
+        help
+          mtrr cleanup spare entries default, it can be changed via
+          mtrr_spare_reg_nr=
+
 config X86_PAT
         bool
         prompt "x86 PAT support"