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-rw-r--r--arch/powerpc/mm/nohash/44x.c242
1 files changed, 242 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/44x.c b/arch/powerpc/mm/nohash/44x.c
new file mode 100644
index 000000000..1beae802b
--- /dev/null
+++ b/arch/powerpc/mm/nohash/44x.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Modifications by Matt Porter (mporter@mvista.com) to support
+ * PPC44x Book E processors.
+ *
+ * This file contains the routines for initializing the MMU
+ * on the 4xx series of chips.
+ * -- paulus
+ *
+ * Derived from arch/ppc/mm/init.c:
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ * and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ * Copyright (C) 1996 Paul Mackerras
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ */
+
+#include <linux/init.h>
+#include <linux/memblock.h>
+
+#include <asm/mmu.h>
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/code-patching.h>
+#include <asm/smp.h>
+
+#include <mm/mmu_decl.h>
+
+/* Used by the 44x TLB replacement exception handler.
+ * Just needed it declared someplace.
+ */
+unsigned int tlb_44x_index; /* = 0 */
+unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
+int icache_44x_need_flush;
+
+unsigned long tlb_47x_boltmap[1024/8];
+
+static void __init ppc44x_update_tlb_hwater(void)
+{
+ /* The TLB miss handlers hard codes the watermark in a cmpli
+ * instruction to improve performances rather than loading it
+ * from the global variable. Thus, we patch the instructions
+ * in the 2 TLB miss handlers when updating the value
+ */
+ modify_instruction_site(&patch__tlb_44x_hwater_D, 0xffff, tlb_44x_hwater);
+ modify_instruction_site(&patch__tlb_44x_hwater_I, 0xffff, tlb_44x_hwater);
+}
+
+/*
+ * "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)
+{
+ unsigned int entry = tlb_44x_hwater--;
+
+ 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"
+ :
+ : "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
+ "r" (phys),
+ "r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
+ "r" (entry),
+ "i" (PPC44x_TLB_PAGEID),
+ "i" (PPC44x_TLB_XLAT),
+ "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 __init 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();
+}
+
+unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
+{
+ unsigned long addr;
+ unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
+
+ /* Pin in enough TLBs to cover any lowmem not covered by the
+ * initial 256M mapping established in head_44x.S */
+ for (addr = memstart + 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);
+ }
+ 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;
+}
+
+void setup_initial_memory_limit(phys_addr_t first_memblock_base,
+ phys_addr_t first_memblock_size)
+{
+ u64 size;
+
+#ifndef CONFIG_NONSTATIC_KERNEL
+ /* We don't currently support the first MEMBLOCK not mapping 0
+ * physical on those processors
+ */
+ BUG_ON(first_memblock_base != 0);
+#endif
+
+ /* 44x has a 256M TLB entry pinned at boot */
+ size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
+ memblock_set_current_limit(first_memblock_base + size);
+}
+
+#ifdef CONFIG_SMP
+void __init mmu_init_secondary(int cpu)
+{
+ unsigned long addr;
+ unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
+
+ /* 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 = memstart + 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 */
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