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authorSerge Semin <Sergey.Semin@baikalelectronics.ru>2020-05-21 17:07:17 +0300
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2020-05-22 09:11:45 +0200
commit742318ad5eeecace49e95da5d3cf4571b0b26b36 (patch)
treecf0d468687673e54bb62194fe3895a931061420f /arch/mips/include/asm/mipsregs.h
parenta2ac81c6ef4018ea49c034ce165bb9ea1cf99f3e (diff)
downloadlinux-742318ad5eeecace49e95da5d3cf4571b0b26b36.tar.bz2
mips: Add CP0 Write Merge config support
CP0 config register may indicate whether write-through merging is allowed. Currently there are two types of the merging available: SysAD Valid and Full modes. Whether each of them are supported by the core is implementation dependent. Moreover whether the ability to change the mode also depends on the chip family instance. Taking into account all of this we created a dedicated mm_config() method to detect and enable merging if it's supported. It is called for MIPS-type processors at CPU-probe stage and attempts to detect whether the write merging is available. If it's known to be supported and switchable, then switch on the full mode. Otherwise just perform the CP0.Config.MM field analysis. In addition there are platforms like InterAptiv/ProAptiv, which do have the MM bit field set by default, but having write-through cacheing unsupported makes write-merging also unsupported. In this case we just ignore the MM field value. Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: devicetree@vger.kernel.org Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips/include/asm/mipsregs.h')
-rw-r--r--arch/mips/include/asm/mipsregs.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 246b8b2ebdf8..a284da54efd5 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -563,6 +563,9 @@
#define MIPS_CONF_MT_FTLB (_ULCAST_(4) << 7)
#define MIPS_CONF_AR (_ULCAST_(7) << 10)
#define MIPS_CONF_AT (_ULCAST_(3) << 13)
+#define MIPS_CONF_MM (_ULCAST_(3) << 17)
+#define MIPS_CONF_MM_SYSAD (_ULCAST_(1) << 17)
+#define MIPS_CONF_MM_FULL (_ULCAST_(2) << 17)
#define MIPS_CONF_M (_ULCAST_(1) << 31)
/*