powerpc/47x: Base ppc476 support

This patch adds the base support for the 476 processor.  The code was
primarily written by Ben Herrenschmidt and Torez Smith, but I've been
maintaining it for a while.

The goal is to have a single binary that will run on 44x and 47x, but
we still have some details to work out.  The biggest is that the L1 cache
line size differs on the two platforms, but it's currently a compile-time
option.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Torez Smith  <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 140 insertions, 4 deletions

diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
index 3986264b099..d8c6efb32bc 100644
--- a/arch/powerpc/mm/44x_mmu.c
+++ b/arch/powerpc/mm/44x_mmu.c
@@ -38,7 +38,9 @@ unsigned int tlb_44x_index; /* = 0 */
 unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
 int icache_44x_need_flush;
 
-static void __init ppc44x_update_tlb_hwater(void)
+unsigned long tlb_47x_boltmap[1024/8];
+
+static void __cpuinit ppc44x_update_tlb_hwater(void)
 {
 	extern unsigned int tlb_44x_patch_hwater_D[];
 	extern unsigned int tlb_44x_patch_hwater_I[];
@@ -59,7 +61,7 @@ static void __init ppc44x_update_tlb_hwater(void)
 }
 
 /*
- * "Pins" a 256MB TLB entry in AS0 for kernel lowmem
+ * "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 44x type MMU
  */
 static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
 {
@@ -67,12 +69,18 @@ static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
 
 	ppc44x_update_tlb_hwater();
 
+	mtspr(SPRN_MMUCR, 0);
+
 	__asm__ __volatile__(
 		"tlbwe	%2,%3,%4\n"
 		"tlbwe	%1,%3,%5\n"
 		"tlbwe	%0,%3,%6\n"
 	:
+#ifdef CONFIG_PPC47x
+	: "r" (PPC47x_TLB2_S_RWX),
+#else
 	: "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
+#endif
 	  "r" (phys),
 	  "r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
 	  "r" (entry),
@@ -81,8 +89,93 @@ static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
 	  "i" (PPC44x_TLB_ATTRIB));
 }
 
+static int __init ppc47x_find_free_bolted(void)
+{
+	unsigned int mmube0 = mfspr(SPRN_MMUBE0);
+	unsigned int mmube1 = mfspr(SPRN_MMUBE1);
+
+	if (!(mmube0 & MMUBE0_VBE0))
+		return 0;
+	if (!(mmube0 & MMUBE0_VBE1))
+		return 1;
+	if (!(mmube0 & MMUBE0_VBE2))
+		return 2;
+	if (!(mmube1 & MMUBE1_VBE3))
+		return 3;
+	if (!(mmube1 & MMUBE1_VBE4))
+		return 4;
+	if (!(mmube1 & MMUBE1_VBE5))
+		return 5;
+	return -1;
+}
+
+static void __init ppc47x_update_boltmap(void)
+{
+	unsigned int mmube0 = mfspr(SPRN_MMUBE0);
+	unsigned int mmube1 = mfspr(SPRN_MMUBE1);
+
+	if (mmube0 & MMUBE0_VBE0)
+		__set_bit((mmube0 >> MMUBE0_IBE0_SHIFT) & 0xff,
+			  tlb_47x_boltmap);
+	if (mmube0 & MMUBE0_VBE1)
+		__set_bit((mmube0 >> MMUBE0_IBE1_SHIFT) & 0xff,
+			  tlb_47x_boltmap);
+	if (mmube0 & MMUBE0_VBE2)
+		__set_bit((mmube0 >> MMUBE0_IBE2_SHIFT) & 0xff,
+			  tlb_47x_boltmap);
+	if (mmube1 & MMUBE1_VBE3)
+		__set_bit((mmube1 >> MMUBE1_IBE3_SHIFT) & 0xff,
+			  tlb_47x_boltmap);
+	if (mmube1 & MMUBE1_VBE4)
+		__set_bit((mmube1 >> MMUBE1_IBE4_SHIFT) & 0xff,
+			  tlb_47x_boltmap);
+	if (mmube1 & MMUBE1_VBE5)
+		__set_bit((mmube1 >> MMUBE1_IBE5_SHIFT) & 0xff,
+			  tlb_47x_boltmap);
+}
+
+/*
+ * "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 47x type MMU
+ */
+static void __cpuinit ppc47x_pin_tlb(unsigned int virt, unsigned int phys)
+{
+	unsigned int rA;
+	int bolted;
+
+	/* Base rA is HW way select, way 0, bolted bit set */
+	rA = 0x88000000;
+
+	/* Look for a bolted entry slot */
+	bolted = ppc47x_find_free_bolted();
+	BUG_ON(bolted < 0);
+
+	/* Insert bolted slot number */
+	rA |= bolted << 24;
+
+	pr_debug("256M TLB entry for 0x%08x->0x%08x in bolt slot %d\n",
+		 virt, phys, bolted);
+
+	mtspr(SPRN_MMUCR, 0);
+
+	__asm__ __volatile__(
+		"tlbwe	%2,%3,0\n"
+		"tlbwe	%1,%3,1\n"
+		"tlbwe	%0,%3,2\n"
+		:
+		: "r" (PPC47x_TLB2_SW | PPC47x_TLB2_SR |
+		       PPC47x_TLB2_SX
+#ifdef CONFIG_SMP
+		       | PPC47x_TLB2_M
+#endif
+		       ),
+		  "r" (phys),
+		  "r" (virt | PPC47x_TLB0_VALID | PPC47x_TLB0_256M),
+		  "r" (rA));
+}
+
 void __init MMU_init_hw(void)
 {
+	/* This is not useful on 47x but won't hurt either */
 	ppc44x_update_tlb_hwater();
 
 	flush_instruction_cache();
@@ -95,8 +188,51 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 	/* Pin in enough TLBs to cover any lowmem not covered by the
 	 * initial 256M mapping established in head_44x.S */
 	for (addr = PPC_PIN_SIZE; addr < lowmem_end_addr;
-	     addr += PPC_PIN_SIZE)
-		ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
+	     addr += PPC_PIN_SIZE) {
+		if (mmu_has_feature(MMU_FTR_TYPE_47x))
+			ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
+		else
+			ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
+	}
+	if (mmu_has_feature(MMU_FTR_TYPE_47x)) {
+		ppc47x_update_boltmap();
 
+#ifdef DEBUG
+		{
+			int i;
+
+			printk(KERN_DEBUG "bolted entries: ");
+			for (i = 0; i < 255; i++) {
+				if (test_bit(i, tlb_47x_boltmap))
+					printk("%d ", i);
+			}
+			printk("\n");
+		}
+#endif /* DEBUG */
+	}
 	return total_lowmem;
 }
+
+#ifdef CONFIG_SMP
+void __cpuinit mmu_init_secondary(int cpu)
+{
+	unsigned long addr;
+
+	/* Pin in enough TLBs to cover any lowmem not covered by the
+	 * initial 256M mapping established in head_44x.S
+	 *
+	 * WARNING: This is called with only the first 256M of the
+	 * linear mapping in the TLB and we can't take faults yet
+	 * so beware of what this code uses. It runs off a temporary
+	 * stack. current (r2) isn't initialized, smp_processor_id()
+	 * will not work, current thread info isn't accessible, ...
+	 */
+	for (addr = PPC_PIN_SIZE; addr < lowmem_end_addr;
+	     addr += PPC_PIN_SIZE) {
+		if (mmu_has_feature(MMU_FTR_TYPE_47x))
+			ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
+		else
+			ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
+	}
+}
+#endif /* CONFIG_SMP */