1 files changed, 279 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
new file mode 100644
index 000000000..3d7dce908
--- /dev/null
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -0,0 +1,279 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_NOHASH_PGTABLE_H
+#define _ASM_POWERPC_NOHASH_PGTABLE_H
+
+#if defined(CONFIG_PPC64)
+#include <asm/nohash/64/pgtable.h>
+#else
+#include <asm/nohash/32/pgtable.h>
+#endif
+
+/* Permission masks used for kernel mappings */
+#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
+#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)
+#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE | _PAGE_GUARDED)
+#define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
+#define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
+#define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
+
+#ifndef __ASSEMBLY__
+
+/* Generic accessors to PTE bits */
+#ifndef pte_write
+static inline int pte_write(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_RW;
+}
+#endif
+#ifndef pte_read
+static inline int pte_read(pte_t pte)		{ return 1; }
+#endif
+static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
+static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
+static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
+static inline bool pte_hashpte(pte_t pte)	{ return false; }
+static inline bool pte_ci(pte_t pte)		{ return pte_val(pte) & _PAGE_NO_CACHE; }
+static inline bool pte_exec(pte_t pte)		{ return pte_val(pte) & _PAGE_EXEC; }
+
+#ifdef CONFIG_NUMA_BALANCING
+/*
+ * These work without NUMA balancing but the kernel does not care. See the
+ * comment in include/linux/pgtable.h . On powerpc, this will only
+ * work for user pages and always return true for kernel pages.
+ */
+static inline int pte_protnone(pte_t pte)
+{
+	return pte_present(pte) && !pte_user(pte);
+}
+
+static inline int pmd_protnone(pmd_t pmd)
+{
+	return pte_protnone(pmd_pte(pmd));
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+static inline int pte_present(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_PRESENT;
+}
+
+static inline bool pte_hw_valid(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_PRESENT;
+}
+
+/*
+ * Don't just check for any non zero bits in __PAGE_USER, since for book3e
+ * and PTE_64BIT, PAGE_KERNEL_X contains _PAGE_BAP_SR which is also in
+ * _PAGE_USER.  Need to explicitly match _PAGE_BAP_UR bit in that case too.
+ */
+#ifndef pte_user
+static inline bool pte_user(pte_t pte)
+{
+	return (pte_val(pte) & _PAGE_USER) == _PAGE_USER;
+}
+#endif
+
+/*
+ * We only find page table entry in the last level
+ * Hence no need for other accessors
+ */
+#define pte_access_permitted pte_access_permitted
+static inline bool pte_access_permitted(pte_t pte, bool write)
+{
+	/*
+	 * A read-only access is controlled by _PAGE_USER bit.
+	 * We have _PAGE_READ set for WRITE and EXECUTE
+	 */
+	if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
+		return false;
+
+	if (write && !pte_write(pte))
+		return false;
+
+	return true;
+}
+
+/* Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ *
+ * Even if PTEs can be unsigned long long, a PFN is always an unsigned
+ * long for now.
+ */
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
+	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
+		     pgprot_val(pgprot)); }
+static inline unsigned long pte_pfn(pte_t pte)	{
+	return pte_val(pte) >> PTE_RPN_SHIFT; }
+
+/* Generic modifiers for PTE bits */
+static inline pte_t pte_exprotect(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_EXEC);
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_DIRTY);
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
+}
+
+static inline pte_t pte_mkspecial(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_SPECIAL);
+}
+
+#ifndef pte_mkhuge
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+	return __pte(pte_val(pte));
+}
+#endif
+
+#ifndef pte_mkprivileged
+static inline pte_t pte_mkprivileged(pte_t pte)
+{
+	return __pte(pte_val(pte) & ~_PAGE_USER);
+}
+#endif
+
+#ifndef pte_mkuser
+static inline pte_t pte_mkuser(pte_t pte)
+{
+	return __pte(pte_val(pte) | _PAGE_USER);
+}
+#endif
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
+}
+
+/* Insert a PTE, top-level function is out of line. It uses an inline
+ * low level function in the respective pgtable-* files
+ */
+extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		       pte_t pte);
+
+/* This low level function performs the actual PTE insertion
+ * Setting the PTE depends on the MMU type and other factors. It's
+ * an horrible mess that I'm not going to try to clean up now but
+ * I'm keeping it in one place rather than spread around
+ */
+static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
+				pte_t *ptep, pte_t pte, int percpu)
+{
+	/* Second case is 32-bit with 64-bit PTE.  In this case, we
+	 * can just store as long as we do the two halves in the right order
+	 * with a barrier in between.
+	 * In the percpu case, we also fallback to the simple update
+	 */
+	if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) {
+		__asm__ __volatile__("\
+			stw%X0 %2,%0\n\
+			mbar\n\
+			stw%X1 %L2,%1"
+		: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
+		: "r" (pte) : "memory");
+		return;
+	}
+	/* Anything else just stores the PTE normally. That covers all 64-bit
+	 * cases, and 32-bit non-hash with 32-bit PTEs.
+	 */
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
+	ptep->pte = ptep->pte1 = ptep->pte2 = ptep->pte3 = pte_val(pte);
+#else
+	*ptep = pte;
+#endif
+
+	/*
+	 * With hardware tablewalk, a sync is needed to ensure that
+	 * subsequent accesses see the PTE we just wrote.  Unlike userspace
+	 * mappings, we can't tolerate spurious faults, so make sure
+	 * the new PTE will be seen the first time.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_BOOK3E_64) && is_kernel_addr(addr))
+		mb();
+}
+
+
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+				 pte_t *ptep, pte_t entry, int dirty);
+
+/*
+ * Macro to mark a page protection value as "uncacheable".
+ */
+
+#define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
+			 _PAGE_WRITETHRU)
+
+#define pgprot_noncached(prot)	  (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+				            _PAGE_NO_CACHE | _PAGE_GUARDED))
+
+#define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+				            _PAGE_NO_CACHE))
+
+#define pgprot_cached(prot)       (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+				            _PAGE_COHERENT))
+
+#if _PAGE_WRITETHRU != 0
+#define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+				            _PAGE_COHERENT | _PAGE_WRITETHRU))
+#else
+#define pgprot_cached_wthru(prot)	pgprot_noncached(prot)
+#endif
+
+#define pgprot_cached_noncoherent(prot) \
+		(__pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL))
+
+#define pgprot_writecombine pgprot_noncached_wc
+
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+				     unsigned long size, pgprot_t vma_prot);
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+
+#ifdef CONFIG_HUGETLB_PAGE
+static inline int hugepd_ok(hugepd_t hpd)
+{
+#ifdef CONFIG_PPC_8xx
+	return ((hpd_val(hpd) & _PMD_PAGE_MASK) == _PMD_PAGE_8M);
+#else
+	/* We clear the top bit to indicate hugepd */
+	return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
+#endif
+}
+
+static inline int pmd_huge(pmd_t pmd)
+{
+	return 0;
+}
+
+static inline int pud_huge(pud_t pud)
+{
+	return 0;
+}
+
+#define is_hugepd(hpd)		(hugepd_ok(hpd))
+#endif
+
+/*
+ * This gets called at the end of handling a page fault, when
+ * the kernel has put a new PTE into the page table for the process.
+ * We use it to ensure coherency between the i-cache and d-cache
+ * for the page which has just been mapped in.
+ */
+#if defined(CONFIG_PPC_E500) && defined(CONFIG_HUGETLB_PAGE)
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
+#else
+static inline
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) {}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif