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-rw-r--r--arch/powerpc/mm/nohash/book3e_pgtable.c132
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);
+}