summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/mm/pgtable_32.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/mm/pgtable_32.c')
-rw-r--r--arch/powerpc/mm/pgtable_32.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
new file mode 100644
index 000000000..5c02fd08d
--- /dev/null
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This file contains the routines setting up the linux page tables.
+ * -- 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/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+#include <linux/set_memory.h>
+
+#include <asm/pgalloc.h>
+#include <asm/fixmap.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/early_ioremap.h>
+
+#include <mm/mmu_decl.h>
+
+static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
+
+notrace void __init early_ioremap_init(void)
+{
+ unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
+ pte_t *ptep = (pte_t *)early_fixmap_pagetable;
+ pmd_t *pmdp = pmd_off_k(addr);
+
+ for (; (s32)(FIXADDR_TOP - addr) > 0;
+ addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
+ pmd_populate_kernel(&init_mm, pmdp, ptep);
+
+ early_ioremap_setup();
+}
+
+static void __init *early_alloc_pgtable(unsigned long size)
+{
+ void *ptr = memblock_alloc(size, size);
+
+ if (!ptr)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+ __func__, size, size);
+
+ return ptr;
+}
+
+pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
+{
+ if (pmd_none(*pmdp)) {
+ pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
+
+ pmd_populate_kernel(&init_mm, pmdp, ptep);
+ }
+ return pte_offset_kernel(pmdp, va);
+}
+
+
+int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
+{
+ pmd_t *pd;
+ pte_t *pg;
+ int err = -ENOMEM;
+
+ /* Use upper 10 bits of VA to index the first level map */
+ pd = pmd_off_k(va);
+ /* Use middle 10 bits of VA to index the second-level map */
+ if (likely(slab_is_available()))
+ pg = pte_alloc_kernel(pd, va);
+ else
+ pg = early_pte_alloc_kernel(pd, va);
+ if (pg) {
+ err = 0;
+ /* The PTE should never be already set nor present in the
+ * hash table
+ */
+ BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
+ set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
+ }
+ smp_wmb();
+ return err;
+}
+
+/*
+ * Map in a chunk of physical memory starting at start.
+ */
+static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
+{
+ unsigned long v, s;
+ phys_addr_t p;
+ bool ktext;
+
+ s = offset;
+ v = PAGE_OFFSET + s;
+ p = memstart_addr + s;
+ for (; s < top; s += PAGE_SIZE) {
+ ktext = core_kernel_text(v);
+ map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
+ v += PAGE_SIZE;
+ p += PAGE_SIZE;
+ }
+}
+
+void __init mapin_ram(void)
+{
+ phys_addr_t base, end;
+ u64 i;
+
+ for_each_mem_range(i, &base, &end) {
+ phys_addr_t top = min(end, total_lowmem);
+
+ if (base >= top)
+ continue;
+ base = mmu_mapin_ram(base, top);
+ __mapin_ram_chunk(base, top);
+ }
+}
+
+void mark_initmem_nx(void)
+{
+ unsigned long numpages = PFN_UP((unsigned long)_einittext) -
+ PFN_DOWN((unsigned long)_sinittext);
+
+ mmu_mark_initmem_nx();
+
+ if (!v_block_mapped((unsigned long)_sinittext)) {
+ set_memory_nx((unsigned long)_sinittext, numpages);
+ set_memory_rw((unsigned long)_sinittext, numpages);
+ }
+}
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+void mark_rodata_ro(void)
+{
+ unsigned long numpages;
+
+ if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE))
+ pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n");
+
+ if (v_block_mapped((unsigned long)_stext + 1)) {
+ mmu_mark_rodata_ro();
+ ptdump_check_wx();
+ return;
+ }
+
+ /*
+ * mark text and rodata as read only. __end_rodata is set by
+ * powerpc's linker script and includes tables and data
+ * requiring relocation which are not put in RO_DATA.
+ */
+ numpages = PFN_UP((unsigned long)__end_rodata) -
+ PFN_DOWN((unsigned long)_stext);
+
+ set_memory_ro((unsigned long)_stext, numpages);
+
+ // mark_initmem_nx() should have already run by now
+ ptdump_check_wx();
+}
+#endif
+
+#if defined(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && defined(CONFIG_DEBUG_PAGEALLOC)
+void __kernel_map_pages(struct page *page, int numpages, int enable)
+{
+ unsigned long addr = (unsigned long)page_address(page);
+
+ if (PageHighMem(page))
+ return;
+
+ if (enable)
+ set_memory_p(addr, numpages);
+ else
+ set_memory_np(addr, numpages);
+}
+#endif /* CONFIG_DEBUG_PAGEALLOC */