MIPS: Add support for FTLBs
The Fixed Page Size TLB (FTLB) is a set-associative dual entry TLB. Its
purpose is to reduce the number of TLB misses by increasing the effective
TLB size and keep the implementation complexity to minimum levels.
A supported core can have both VTLB and FTLB.
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6139/
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index 21c8e29..8f7adf0 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -52,6 +52,9 @@
unsigned int cputype;
int isa_level;
int tlbsize;
+ int tlbsizevtlb;
+ int tlbsizeftlbsets;
+ int tlbsizeftlbways;
struct cache_desc icache; /* Primary I-cache */
struct cache_desc dcache; /* Primary D or combined I/D cache */
struct cache_desc scache; /* Secondary cache */
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index d9910a1..cb57e07 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -645,6 +645,8 @@
#define MIPS_CONF5_K (_ULCAST_(1) << 30)
#define MIPS_CONF6_SYND (_ULCAST_(1) << 13)
+/* proAptiv FTLB on/off bit */
+#define MIPS_CONF6_FTLBEN (_ULCAST_(1) << 15)
#define MIPS_CONF7_WII (_ULCAST_(1) << 31)
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index f6be474..5e08bcc 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -11,6 +11,8 @@
#include <spaces.h>
#include <linux/const.h>
+#include <linux/kernel.h>
+#include <asm/mipsregs.h>
/*
* PAGE_SHIFT determines the page size
@@ -33,6 +35,29 @@
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
+/*
+ * This is used for calculating the real page sizes
+ * for FTLB or VTLB + FTLB confugrations.
+ */
+static inline unsigned int page_size_ftlb(unsigned int mmuextdef)
+{
+ switch (mmuextdef) {
+ case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT:
+ if (PAGE_SIZE == (1 << 30))
+ return 5;
+ if (PAGE_SIZE == (1llu << 32))
+ return 6;
+ if (PAGE_SIZE > (256 << 10))
+ return 7; /* reserved */
+ /* fall through */
+ case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT:
+ return (PAGE_SHIFT - 10) / 2;
+ default:
+ panic("Invalid FTLB configuration with Conf4_mmuextdef=%d value\n",
+ mmuextdef >> 14);
+ }
+}
+
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
#define HPAGE_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3)
#define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT)