ppc/85xx: Introduce low level write_tlb function

Factor out the code we use to actually write a tlb entry.

set_tlb is a logical view of the TLB while write_tlb is a low level
matching the MAS registers.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

cpu/mpc85xx/start.S

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004, 2007 Freescale Semiconductor.
+ * Copyright 2004, 2007-2009 Freescale Semiconductor.
  * Copyright (C) 2003  Motorola,Inc.
  *
  * See file CREDITS for list of people who contributed to this
@@ -821,6 +821,28 @@ in32r:
 /*------------------------------------------------------------------------------*/
 
 /*
+ * void write_tlb(mas0, mas1, mas2, mas3, mas7)
+ */
+	.globl	write_tlb
+write_tlb:
+	mtspr	MAS0,r3
+	mtspr	MAS1,r4
+	mtspr	MAS2,r5
+	mtspr	MAS3,r6
+#ifdef CONFIG_ENABLE_36BIT_PHYS
+	mtspr	MAS7,r7
+#endif
+	li	r3,0
+#ifdef CONFIG_SYS_BOOK3E_HV
+	mtspr	MAS8,r3
+#endif
+	isync
+	tlbwe
+	msync
+	isync
+	blr
+
+/*
  * void relocate_code (addr_sp, gd, addr_moni)
  *
  * This "function" does not return, instead it continues in RAM

cpu/mpc85xx/tlb.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008 Freescale Semiconductor, Inc.
+ * Copyright 2008-2009 Freescale Semiconductor, Inc.
  *
  * (C) Copyright 2000
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
@@ -42,19 +42,9 @@ void set_tlb(u8 tlb, u32 epn, u64 rpn,
 	_mas1 = FSL_BOOKE_MAS1(1, iprot, 0, ts, tsize);
 	_mas2 = FSL_BOOKE_MAS2(epn, wimge);
 	_mas3 = FSL_BOOKE_MAS3(rpn, 0, perms);
-	_mas7 = rpn >> 32;
+	_mas7 = FSL_BOOKE_MAS7(rpn);
 
-	mtspr(MAS0, _mas0);
-	mtspr(MAS1, _mas1);
-	mtspr(MAS2, _mas2);
-	mtspr(MAS3, _mas3);
-#ifdef CONFIG_ENABLE_36BIT_PHYS
-	mtspr(MAS7, _mas7);
-#endif
-#ifdef CONFIG_SYS_BOOK3E_HV
-	mtspr(MAS8, 0);
-#endif
-	asm volatile("isync;msync;tlbwe;isync");
+	write_tlb(_mas0, _mas1, _mas2, _mas3, _mas7);
 
 #ifdef CONFIG_ADDR_MAP
 	if ((tlb == 1) && (gd->flags & GD_FLG_RELOC))

include/asm-ppc/mmu.h

@@ -450,6 +450,8 @@ extern void print_bats(void);
 		(((epn) & MAS3_RPN) | (wimge))
 #define FSL_BOOKE_MAS3(rpn, user, perms) \
 		(((rpn) & MAS3_RPN) | (user) | (perms))
+#define FSL_BOOKE_MAS7(rpn) \
+		(((u64)(rpn)) >> 32)
 
 #define BOOKE_PAGESZ_1K         0
 #define BOOKE_PAGESZ_4K         1
@@ -480,6 +482,8 @@ extern int find_tlb_idx(void *addr, u8 tlbsel);
 
 extern unsigned int setup_ddr_tlbs(unsigned int memsize_in_meg);
 
+extern void write_tlb(u32 _mas0, u32 _mas1, u32 _mas2, u32 _mas3, u32 _mas7);
+
 #define SET_TLB_ENTRY(_tlb, _epn, _rpn, _perms, _wimge, _ts, _esel, _sz, _iprot) \
 	{ .tlb = _tlb, .epn = _epn, .rpn = _rpn, .perms = _perms, \
 	  .wimge = _wimge, .ts = _ts, .esel = _esel, .tsize = _sz, .iprot = _iprot }