1 files changed, 389 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
new file mode 100644
index 000000000..f99c53a5f
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -0,0 +1,389 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_NOHASH_32_PGTABLE_H
+#define _ASM_POWERPC_NOHASH_32_PGTABLE_H
+
+#include <asm-generic/pgtable-nopmd.h>
+
+#ifndef __ASSEMBLY__
+#include <linux/sched.h>
+#include <linux/threads.h>
+#include <asm/mmu.h>			/* For sub-arch specific PPC_PIN_SIZE */
+
+#ifdef CONFIG_44x
+extern int icache_44x_need_flush;
+#endif
+
+#endif /* __ASSEMBLY__ */
+
+#define PTE_INDEX_SIZE	PTE_SHIFT
+#define PMD_INDEX_SIZE	0
+#define PUD_INDEX_SIZE	0
+#define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
+
+#define PMD_CACHE_INDEX	PMD_INDEX_SIZE
+#define PUD_CACHE_INDEX	PUD_INDEX_SIZE
+
+#ifndef __ASSEMBLY__
+#define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
+#define PMD_TABLE_SIZE	0
+#define PUD_TABLE_SIZE	0
+#define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
+
+#define PMD_MASKED_BITS (PTE_TABLE_SIZE - 1)
+#endif	/* __ASSEMBLY__ */
+
+#define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
+#define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
+
+/*
+ * The normal case is that PTEs are 32-bits and we have a 1-page
+ * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
+ *
+ * For any >32-bit physical address platform, we can use the following
+ * two level page table layout where the pgdir is 8KB and the MS 13 bits
+ * are an index to the second level table.  The combined pgdir/pmd first
+ * level has 2048 entries and the second level has 512 64-bit PTE entries.
+ * -Matt
+ */
+/* PGDIR_SHIFT determines what a top-level page table entry can map */
+#define PGDIR_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+/* Bits to mask out from a PGD to get to the PUD page */
+#define PGD_MASKED_BITS		0
+
+#define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
+
+#define pte_ERROR(e) \
+	pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
+		(unsigned long long)pte_val(e))
+#define pgd_ERROR(e) \
+	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+#ifndef __ASSEMBLY__
+
+int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
+void unmap_kernel_page(unsigned long va);
+
+#endif /* !__ASSEMBLY__ */
+
+
+/*
+ * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
+ * value (for now) on others, from where we can start layout kernel
+ * virtual space that goes below PKMAP and FIXMAP
+ */
+#include <asm/fixmap.h>
+
+/*
+ * ioremap_bot starts at that address. Early ioremaps move down from there,
+ * until mem_init() at which point this becomes the top of the vmalloc
+ * and ioremap space
+ */
+#ifdef CONFIG_HIGHMEM
+#define IOREMAP_TOP	PKMAP_BASE
+#else
+#define IOREMAP_TOP	FIXADDR_START
+#endif
+
+/* PPC32 shares vmalloc area with ioremap */
+#define IOREMAP_START	VMALLOC_START
+#define IOREMAP_END	VMALLOC_END
+
+/*
+ * Just any arbitrary offset to the start of the vmalloc VM area: the
+ * current 16MB value just means that there will be a 64MB "hole" after the
+ * physical memory until the kernel virtual memory starts.  That means that
+ * any out-of-bounds memory accesses will hopefully be caught.
+ * The vmalloc() routines leaves a hole of 4kB between each vmalloced
+ * area for the same reason. ;)
+ *
+ * We no longer map larger than phys RAM with the BATs so we don't have
+ * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
+ * about clashes between our early calls to ioremap() that start growing down
+ * from IOREMAP_TOP being run into the VM area allocations (growing upwards
+ * from VMALLOC_START).  For this reason we have ioremap_bot to check when
+ * we actually run into our mappings setup in the early boot with the VM
+ * system.  This really does become a problem for machines with good amounts
+ * of RAM.  -- Cort
+ */
+#define VMALLOC_OFFSET (0x1000000) /* 16M */
+#ifdef PPC_PIN_SIZE
+#define VMALLOC_START (((ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
+#else
+#define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
+#endif
+
+#ifdef CONFIG_KASAN_VMALLOC
+#define VMALLOC_END	ALIGN_DOWN(ioremap_bot, PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
+#else
+#define VMALLOC_END	ioremap_bot
+#endif
+
+/*
+ * Bits in a linux-style PTE.  These match the bits in the
+ * (hardware-defined) PowerPC PTE as closely as possible.
+ */
+
+#if defined(CONFIG_40x)
+#include <asm/nohash/32/pte-40x.h>
+#elif defined(CONFIG_44x)
+#include <asm/nohash/32/pte-44x.h>
+#elif defined(CONFIG_PPC_85xx) && defined(CONFIG_PTE_64BIT)
+#include <asm/nohash/pte-e500.h>
+#elif defined(CONFIG_PPC_85xx)
+#include <asm/nohash/32/pte-85xx.h>
+#elif defined(CONFIG_PPC_8xx)
+#include <asm/nohash/32/pte-8xx.h>
+#endif
+
+/*
+ * Location of the PFN in the PTE. Most 32-bit platforms use the same
+ * as _PAGE_SHIFT here (ie, naturally aligned).
+ * Platform who don't just pre-define the value so we don't override it here.
+ */
+#ifndef PTE_RPN_SHIFT
+#define PTE_RPN_SHIFT	(PAGE_SHIFT)
+#endif
+
+/*
+ * The mask covered by the RPN must be a ULL on 32-bit platforms with
+ * 64-bit PTEs.
+ */
+#if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
+#define PTE_RPN_MASK	(~((1ULL << PTE_RPN_SHIFT) - 1))
+#define MAX_POSSIBLE_PHYSMEM_BITS 36
+#else
+#define PTE_RPN_MASK	(~((1UL << PTE_RPN_SHIFT) - 1))
+#define MAX_POSSIBLE_PHYSMEM_BITS 32
+#endif
+
+/*
+ * _PAGE_CHG_MASK masks of bits that are to be preserved across
+ * pgprot changes.
+ */
+#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
+
+#ifndef __ASSEMBLY__
+
+#define pte_clear(mm, addr, ptep) \
+	do { pte_update(mm, addr, ptep, ~0, 0, 0); } while (0)
+
+#ifndef pte_mkwrite_novma
+static inline pte_t pte_mkwrite_novma(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_RW);
+}
+#endif
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_DIRTY);
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_ACCESSED);
+}
+
+#ifndef pte_wrprotect
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_RW);
+}
+#endif
+
+#ifndef pte_mkexec
+static inline pte_t pte_mkexec(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_EXEC);
+}
+#endif
+
+#define pmd_none(pmd)		(!pmd_val(pmd))
+#define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
+#define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
+static inline void pmd_clear(pmd_t *pmdp)
+{
+	*pmdp = __pmd(0);
+}
+
+/*
+ * PTE updates. This function is called whenever an existing
+ * valid PTE is updated. This does -not- include set_pte_at()
+ * which nowadays only sets a new PTE.
+ *
+ * Depending on the type of MMU, we may need to use atomic updates
+ * and the PTE may be either 32 or 64 bit wide. In the later case,
+ * when using atomic updates, only the low part of the PTE is
+ * accessed atomically.
+ *
+ * In addition, on 44x, we also maintain a global flag indicating
+ * that an executable user mapping was modified, which is needed
+ * to properly flush the virtually tagged instruction cache of
+ * those implementations.
+ *
+ * On the 8xx, the page tables are a bit special. For 16k pages, we have
+ * 4 identical entries. For 512k pages, we have 128 entries as if it was
+ * 4k pages, but they are flagged as 512k pages for the hardware.
+ * For other page sizes, we have a single entry in the table.
+ */
+#ifdef CONFIG_PPC_8xx
+static pmd_t *pmd_off(struct mm_struct *mm, unsigned long addr);
+static int hugepd_ok(hugepd_t hpd);
+
+static int number_of_cells_per_pte(pmd_t *pmd, pte_basic_t val, int huge)
+{
+	if (!huge)
+		return PAGE_SIZE / SZ_4K;
+	else if (hugepd_ok(*((hugepd_t *)pmd)))
+		return 1;
+	else if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && !(val & _PAGE_HUGE))
+		return SZ_16K / SZ_4K;
+	else
+		return SZ_512K / SZ_4K;
+}
+
+static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
+				     unsigned long clr, unsigned long set, int huge)
+{
+	pte_basic_t *entry = (pte_basic_t *)p;
+	pte_basic_t old = pte_val(*p);
+	pte_basic_t new = (old & ~(pte_basic_t)clr) | set;
+	int num, i;
+	pmd_t *pmd = pmd_off(mm, addr);
+
+	num = number_of_cells_per_pte(pmd, new, huge);
+
+	for (i = 0; i < num; i += PAGE_SIZE / SZ_4K, new += PAGE_SIZE) {
+		*entry++ = new;
+		if (IS_ENABLED(CONFIG_PPC_16K_PAGES) && num != 1) {
+			*entry++ = new;
+			*entry++ = new;
+			*entry++ = new;
+		}
+	}
+
+	return old;
+}
+
+#ifdef CONFIG_PPC_16K_PAGES
+#define ptep_get ptep_get
+static inline pte_t ptep_get(pte_t *ptep)
+{
+	pte_basic_t val = READ_ONCE(ptep->pte);
+	pte_t pte = {val, val, val, val};
+
+	return pte;
+}
+#endif /* CONFIG_PPC_16K_PAGES */
+
+#else
+static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
+				     unsigned long clr, unsigned long set, int huge)
+{
+	pte_basic_t old = pte_val(*p);
+	pte_basic_t new = (old & ~(pte_basic_t)clr) | set;
+
+	*p = __pte(new);
+
+#ifdef CONFIG_44x
+	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
+		icache_44x_need_flush = 1;
+#endif
+	return old;
+}
+#endif
+
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
+					      unsigned long addr, pte_t *ptep)
+{
+	unsigned long old;
+	old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
+	return (old & _PAGE_ACCESSED) != 0;
+}
+#define ptep_test_and_clear_young(__vma, __addr, __ptep) \
+	__ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep)
+
+#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
+static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+				       pte_t *ptep)
+{
+	return __pte(pte_update(mm, addr, ptep, ~0, 0, 0));
+}
+
+#define __HAVE_ARCH_PTEP_SET_WRPROTECT
+#ifndef ptep_set_wrprotect
+static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
+				      pte_t *ptep)
+{
+	pte_update(mm, addr, ptep, _PAGE_RW, 0, 0);
+}
+#endif
+
+#ifndef __ptep_set_access_flags
+static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
+					   pte_t *ptep, pte_t entry,
+					   unsigned long address,
+					   int psize)
+{
+	unsigned long set = pte_val(entry) &
+			    (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
+	int huge = psize > mmu_virtual_psize ? 1 : 0;
+
+	pte_update(vma->vm_mm, address, ptep, 0, set, huge);
+
+	flush_tlb_page(vma, address);
+}
+#endif
+
+static inline int pte_young(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_ACCESSED;
+}
+
+/*
+ * Note that on Book E processors, the pmd contains the kernel virtual
+ * (lowmem) address of the pte page.  The physical address is less useful
+ * because everything runs with translation enabled (even the TLB miss
+ * handler).  On everything else the pmd contains the physical address
+ * of the pte page.  -- paulus
+ */
+#ifndef CONFIG_BOOKE
+#define pmd_pfn(pmd)		(pmd_val(pmd) >> PAGE_SHIFT)
+#else
+#define pmd_page_vaddr(pmd)	\
+	((const void *)(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
+#define pmd_pfn(pmd)		(__pa(pmd_val(pmd)) >> PAGE_SHIFT)
+#endif
+
+#define pmd_page(pmd)		pfn_to_page(pmd_pfn(pmd))
+
+/*
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
+ *
+ * Format of swap PTEs (32bit PTEs):
+ *
+ *                         1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *   <------------------ offset -------------------> < type -> E 0 0
+ *
+ * E is the exclusive marker that is not stored in swap entries.
+ *
+ * For 64bit PTEs, the offset is extended by 32bit.
+ */
+#define __swp_type(entry)		((entry).val & 0x1f)
+#define __swp_offset(entry)		((entry).val >> 5)
+#define __swp_entry(type, offset)	((swp_entry_t) { ((type) & 0x1f) | ((offset) << 5) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
+
+/* We borrow LSB 2 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE	0x000004
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_POWERPC_NOHASH_32_PGTABLE_H */