1 files changed, 132 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/book3e_pgtable.c b/arch/powerpc/mm/nohash/book3e_pgtable.c
new file mode 100644
index 000000000..b80fc4a91
--- /dev/null
+++ b/arch/powerpc/mm/nohash/book3e_pgtable.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2005, Paul Mackerras, IBM Corporation.
+ * Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
+ * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
+ */
+
+#include <linux/sched.h>
+#include <linux/memblock.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/dma.h>
+#include <asm/code-patching.h>
+
+#include <mm/mmu_decl.h>
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+/*
+ * On Book3E CPUs, the vmemmap is currently mapped in the top half of
+ * the vmalloc space using normal page tables, though the size of
+ * pages encoded in the PTEs can be different
+ */
+int __meminit vmemmap_create_mapping(unsigned long start,
+				     unsigned long page_size,
+				     unsigned long phys)
+{
+	/* Create a PTE encoding without page size */
+	unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
+		_PAGE_KERNEL_RW;
+
+	/* PTEs only contain page size encodings up to 32M */
+	BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
+
+	/* Encode the size in the PTE */
+	flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
+
+	/* For each PTE for that area, map things. Note that we don't
+	 * increment phys because all PTEs are of the large size and
+	 * thus must have the low bits clear
+	 */
+	for (i = 0; i < page_size; i += PAGE_SIZE)
+		BUG_ON(map_kernel_page(start + i, phys, __pgprot(flags)));
+
+	return 0;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+void vmemmap_remove_mapping(unsigned long start,
+			    unsigned long page_size)
+{
+}
+#endif
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+static void __init *early_alloc_pgtable(unsigned long size)
+{
+	void *ptr;
+
+	ptr = memblock_alloc_try_nid(size, size, MEMBLOCK_LOW_LIMIT,
+				     __pa(MAX_DMA_ADDRESS), NUMA_NO_NODE);
+
+	if (!ptr)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx max_addr=%lx\n",
+		      __func__, size, size, __pa(MAX_DMA_ADDRESS));
+
+	return ptr;
+}
+
+/*
+ * map_kernel_page currently only called by __ioremap
+ * map_kernel_page adds an entry to the ioremap page table
+ * and adds an entry to the HPT, possibly bolting it
+ */
+int __ref map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
+{
+	pgd_t *pgdp;
+	p4d_t *p4dp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+
+	BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
+	if (slab_is_available()) {
+		pgdp = pgd_offset_k(ea);
+		p4dp = p4d_offset(pgdp, ea);
+		pudp = pud_alloc(&init_mm, p4dp, ea);
+		if (!pudp)
+			return -ENOMEM;
+		pmdp = pmd_alloc(&init_mm, pudp, ea);
+		if (!pmdp)
+			return -ENOMEM;
+		ptep = pte_alloc_kernel(pmdp, ea);
+		if (!ptep)
+			return -ENOMEM;
+	} else {
+		pgdp = pgd_offset_k(ea);
+		p4dp = p4d_offset(pgdp, ea);
+		if (p4d_none(*p4dp)) {
+			pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
+			p4d_populate(&init_mm, p4dp, pudp);
+		}
+		pudp = pud_offset(p4dp, ea);
+		if (pud_none(*pudp)) {
+			pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
+			pud_populate(&init_mm, pudp, pmdp);
+		}
+		pmdp = pmd_offset(pudp, ea);
+		if (!pmd_present(*pmdp)) {
+			ptep = early_alloc_pgtable(PTE_TABLE_SIZE);
+			pmd_populate_kernel(&init_mm, pmdp, ptep);
+		}
+		ptep = pte_offset_kernel(pmdp, ea);
+	}
+	set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
+
+	smp_wmb();
+	return 0;
+}
+
+void __patch_exception(int exc, unsigned long addr)
+{
+	unsigned int *ibase = &interrupt_base_book3e;
+
+	/*
+	 * Our exceptions vectors start with a NOP and -then- a branch
+	 * to deal with single stepping from userspace which stops on
+	 * the second instruction. Thus we need to patch the second
+	 * instruction of the exception, not the first one.
+	 */
+
+	patch_branch(ibase + (exc / 4) + 1, addr, 0);
+}