Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 485 insertions, 0 deletions

diff --git a/arch/hexagon/include/asm/pgtable.h b/arch/hexagon/include/asm/pgtable.h
new file mode 100644
index 000000000..65125d0b0
--- /dev/null
+++ b/arch/hexagon/include/asm/pgtable.h
@@ -0,0 +1,485 @@
+/*
+ * Page table support for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_PGTABLE_H
+#define _ASM_PGTABLE_H
+
+/*
+ * Page table definitions for Qualcomm Hexagon processor.
+ */
+#include <asm/page.h>
+#define __ARCH_USE_5LEVEL_HACK
+#include <asm-generic/pgtable-nopmd.h>
+
+/* A handy thing to have if one has the RAM. Declared in head.S */
+extern unsigned long empty_zero_page;
+
+/*
+ * The PTE model described here is that of the Hexagon Virtual Machine,
+ * which autonomously walks 2-level page tables.  At a lower level, we
+ * also describe the RISCish software-loaded TLB entry structure of
+ * the underlying Hexagon processor. A kernel built to run on the
+ * virtual machine has no need to know about the underlying hardware.
+ */
+#include <asm/vm_mmu.h>
+
+/*
+ * To maximize the comfort level for the PTE manipulation macros,
+ * define the "well known" architecture-specific bits.
+ */
+#define _PAGE_READ	__HVM_PTE_R
+#define _PAGE_WRITE	__HVM_PTE_W
+#define _PAGE_EXECUTE	__HVM_PTE_X
+#define _PAGE_USER	__HVM_PTE_U
+
+/*
+ * We have a total of 4 "soft" bits available in the abstract PTE.
+ * The two mandatory software bits are Dirty and Accessed.
+ * To make nonlinear swap work according to the more recent
+ * model, we want a low order "Present" bit to indicate whether
+ * the PTE describes MMU programming or swap space.
+ */
+#define _PAGE_PRESENT	(1<<0)
+#define _PAGE_DIRTY	(1<<1)
+#define _PAGE_ACCESSED	(1<<2)
+
+/*
+ * For now, let's say that Valid and Present are the same thing.
+ * Alternatively, we could say that it's the "or" of R, W, and X
+ * permissions.
+ */
+#define _PAGE_VALID	_PAGE_PRESENT
+
+/*
+ * We're not defining _PAGE_GLOBAL here, since there's no concept
+ * of global pages or ASIDs exposed to the Hexagon Virtual Machine,
+ * and we want to use the same page table structures and macros in
+ * the native kernel as we do in the virtual machine kernel.
+ * So we'll put up with a bit of inefficiency for now...
+ */
+
+/*
+ * Top "FOURTH" level (pgd), which for the Hexagon VM is really
+ * only the second from the bottom, pgd and pud both being collapsed.
+ * Each entry represents 4MB of virtual address space, 4K of table
+ * thus maps the full 4GB.
+ */
+#define PGDIR_SHIFT 22
+#define PTRS_PER_PGD 1024
+
+#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK (~(PGDIR_SIZE-1))
+
+#ifdef CONFIG_PAGE_SIZE_4KB
+#define PTRS_PER_PTE 1024
+#endif
+
+#ifdef CONFIG_PAGE_SIZE_16KB
+#define PTRS_PER_PTE 256
+#endif
+
+#ifdef CONFIG_PAGE_SIZE_64KB
+#define PTRS_PER_PTE 64
+#endif
+
+#ifdef CONFIG_PAGE_SIZE_256KB
+#define PTRS_PER_PTE 16
+#endif
+
+#ifdef CONFIG_PAGE_SIZE_1MB
+#define PTRS_PER_PTE 4
+#endif
+
+/*  Any bigger and the PTE disappears.  */
+#define pgd_ERROR(e) \
+	printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__,\
+		pgd_val(e))
+
+/*
+ * Page Protection Constants. Includes (in this variant) cache attributes.
+ */
+extern unsigned long _dflt_cache_att;
+
+#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER | \
+				_dflt_cache_att)
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | \
+				_PAGE_READ | _PAGE_EXECUTE | _dflt_cache_att)
+#define PAGE_COPY	PAGE_READONLY
+#define PAGE_EXEC	__pgprot(_PAGE_PRESENT | _PAGE_USER | \
+				_PAGE_READ | _PAGE_EXECUTE | _dflt_cache_att)
+#define PAGE_COPY_EXEC	PAGE_EXEC
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | \
+				_PAGE_EXECUTE | _PAGE_WRITE | _dflt_cache_att)
+#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_READ | \
+				_PAGE_WRITE | _PAGE_EXECUTE | _dflt_cache_att)
+
+
+/*
+ * Aliases for mapping mmap() protection bits to page protections.
+ * These get used for static initialization, so using the _dflt_cache_att
+ * variable for the default cache attribute isn't workable. If the
+ * default gets changed at boot time, the boot option code has to
+ * update data structures like the protaction_map[] array.
+ */
+#define CACHEDEF	(CACHE_DEFAULT << 6)
+
+/* Private (copy-on-write) page protections. */
+#define __P000 __pgprot(_PAGE_PRESENT | _PAGE_USER | CACHEDEF)
+#define __P001 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | CACHEDEF)
+#define __P010 __P000	/* Write-only copy-on-write */
+#define __P011 __P001	/* Read/Write copy-on-write */
+#define __P100 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
+			_PAGE_EXECUTE | CACHEDEF)
+#define __P101 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_EXECUTE | \
+			_PAGE_READ | CACHEDEF)
+#define __P110 __P100	/* Write/execute copy-on-write */
+#define __P111 __P101	/* Read/Write/Execute, copy-on-write */
+
+/* Shared page protections. */
+#define __S000 __P000
+#define __S001 __P001
+#define __S010 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
+			_PAGE_WRITE | CACHEDEF)
+#define __S011 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | \
+			_PAGE_WRITE | CACHEDEF)
+#define __S100 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
+			_PAGE_EXECUTE | CACHEDEF)
+#define __S101 __P101
+#define __S110 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
+			_PAGE_EXECUTE | _PAGE_WRITE | CACHEDEF)
+#define __S111 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | \
+			_PAGE_EXECUTE | _PAGE_WRITE | CACHEDEF)
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];  /* located in head.S */
+
+/* Seems to be zero even in architectures where the zero page is firewalled? */
+#define FIRST_USER_ADDRESS 0UL
+#define pte_special(pte)	0
+#define pte_mkspecial(pte)	(pte)
+
+/*  HUGETLB not working currently  */
+#ifdef CONFIG_HUGETLB_PAGE
+#define pte_mkhuge(pte) __pte((pte_val(pte) & ~0x3) | HVM_HUGEPAGE_SIZE)
+#endif
+
+/*
+ * For now, assume that higher-level code will do TLB/MMU invalidations
+ * and don't insert that overhead into this low-level function.
+ */
+extern void sync_icache_dcache(pte_t pte);
+
+#define pte_present_exec_user(pte) \
+	((pte_val(pte) & (_PAGE_EXECUTE | _PAGE_USER)) == \
+	(_PAGE_EXECUTE | _PAGE_USER))
+
+static inline void set_pte(pte_t *ptep, pte_t pteval)
+{
+	/*  should really be using pte_exec, if it weren't declared later. */
+	if (pte_present_exec_user(pteval))
+		sync_icache_dcache(pteval);
+
+	*ptep = pteval;
+}
+
+/*
+ * For the Hexagon Virtual Machine MMU (or its emulation), a null/invalid
+ * L1 PTE (PMD/PGD) has 7 in the least significant bits. For the L2 PTE
+ * (Linux PTE), the key is to have bits 11..9 all zero.  We'd use 0x7
+ * as a universal null entry, but some of those least significant bits
+ * are interpreted by software.
+ */
+#define _NULL_PMD	0x7
+#define _NULL_PTE	0x0
+
+static inline void pmd_clear(pmd_t *pmd_entry_ptr)
+{
+	 pmd_val(*pmd_entry_ptr) = _NULL_PMD;
+}
+
+/*
+ * Conveniently, a null PTE value is invalid.
+ */
+static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
+				pte_t *ptep)
+{
+	pte_val(*ptep) = _NULL_PTE;
+}
+
+#ifdef NEED_PMD_INDEX_DESPITE_BEING_2_LEVEL
+/**
+ * pmd_index - returns the index of the entry in the PMD page
+ * which would control the given virtual address
+ */
+#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
+#endif
+
+/**
+ * pgd_index - returns the index of the entry in the PGD page
+ * which would control the given virtual address
+ *
+ * This returns the *index* for the address in the pgd_t
+ */
+#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
+
+/*
+ * pgd_offset - find an offset in a page-table-directory
+ */
+#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
+
+/*
+ * pgd_offset_k - get kernel (init_mm) pgd entry pointer for addr
+ */
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+
+/**
+ * pmd_none - check if pmd_entry is mapped
+ * @pmd_entry:  pmd entry
+ *
+ * MIPS checks it against that "invalid pte table" thing.
+ */
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == _NULL_PMD;
+}
+
+/**
+ * pmd_present - is there a page table behind this?
+ * Essentially the inverse of pmd_none.  We maybe
+ * save an inline instruction by defining it this
+ * way, instead of simply "!pmd_none".
+ */
+static inline int pmd_present(pmd_t pmd)
+{
+	return pmd_val(pmd) != (unsigned long)_NULL_PMD;
+}
+
+/**
+ * pmd_bad - check if a PMD entry is "bad". That might mean swapped out.
+ * As we have no known cause of badness, it's null, as it is for many
+ * architectures.
+ */
+static inline int pmd_bad(pmd_t pmd)
+{
+	return 0;
+}
+
+/*
+ * pmd_page - converts a PMD entry to a page pointer
+ */
+#define pmd_page(pmd)  (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
+#define pmd_pgtable(pmd) pmd_page(pmd)
+
+/**
+ * pte_none - check if pte is mapped
+ * @pte: pte_t entry
+ */
+static inline int pte_none(pte_t pte)
+{
+	return pte_val(pte) == _NULL_PTE;
+};
+
+/*
+ * pte_present - check if page is present
+ */
+static inline int pte_present(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_PRESENT;
+}
+
+/* mk_pte - make a PTE out of a page pointer and protection bits */
+#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
+
+/* pte_page - returns a page (frame pointer/descriptor?) based on a PTE */
+#define pte_page(x) pfn_to_page(pte_pfn(x))
+
+/* pte_mkold - mark PTE as not recently accessed */
+static inline pte_t pte_mkold(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_ACCESSED;
+	return pte;
+}
+
+/* pte_mkyoung - mark PTE as recently accessed */
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_ACCESSED;
+	return pte;
+}
+
+/* pte_mkclean - mark page as in sync with backing store */
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_DIRTY;
+	return pte;
+}
+
+/* pte_mkdirty - mark page as modified */
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+/* pte_young - "is PTE marked as accessed"? */
+static inline int pte_young(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_ACCESSED;
+}
+
+/* pte_dirty - "is PTE dirty?" */
+static inline int pte_dirty(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_DIRTY;
+}
+
+/* pte_modify - set protection bits on PTE */
+static inline pte_t pte_modify(pte_t pte, pgprot_t prot)
+{
+	pte_val(pte) &= PAGE_MASK;
+	pte_val(pte) |= pgprot_val(prot);
+	return pte;
+}
+
+/* pte_wrprotect - mark page as not writable */
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_WRITE;
+	return pte;
+}
+
+/* pte_mkwrite - mark page as writable */
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_WRITE;
+	return pte;
+}
+
+/* pte_mkexec - mark PTE as executable */
+static inline pte_t pte_mkexec(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_EXECUTE;
+	return pte;
+}
+
+/* pte_read - "is PTE marked as readable?" */
+static inline int pte_read(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_READ;
+}
+
+/* pte_write - "is PTE marked as writable?" */
+static inline int pte_write(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_WRITE;
+}
+
+
+/* pte_exec - "is PTE marked as executable?" */
+static inline int pte_exec(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_EXECUTE;
+}
+
+/* __pte_to_swp_entry - extract swap entry from PTE */
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+
+/* __swp_entry_to_pte - extract PTE from swap entry */
+#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+
+/* pfn_pte - convert page number and protection value to page table entry */
+#define pfn_pte(pfn, pgprot) __pte((pfn << PAGE_SHIFT) | pgprot_val(pgprot))
+
+/* pte_pfn - convert pte to page frame number */
+#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+
+/*
+ * set_pte_at - update page table and do whatever magic may be
+ * necessary to make the underlying hardware/firmware take note.
+ *
+ * VM may require a virtual instruction to alert the MMU.
+ */
+#define set_pte_at(mm, addr, ptep, pte) set_pte(ptep, pte)
+
+/*
+ * May need to invoke the virtual machine as well...
+ */
+#define pte_unmap(pte)		do { } while (0)
+#define pte_unmap_nested(pte)	do { } while (0)
+
+/*
+ * pte_offset_map - returns the linear address of the page table entry
+ * corresponding to an address
+ */
+#define pte_offset_map(dir, address)                                    \
+	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
+
+#define pte_offset_map_nested(pmd, addr) pte_offset_map(pmd, addr)
+
+/* pte_offset_kernel - kernel version of pte_offset */
+#define pte_offset_kernel(dir, address) \
+	((pte_t *) (unsigned long) __va(pmd_val(*dir) & PAGE_MASK) \
+				+  __pte_offset(address))
+
+/* ZERO_PAGE - returns the globally shared zero page */
+#define ZERO_PAGE(vaddr) (virt_to_page(&empty_zero_page))
+
+#define __pte_offset(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+
+/*  I think this is in case we have page table caches; needed by init/main.c  */
+#define pgtable_cache_init()    do { } while (0)
+
+/*
+ * Swap/file PTE definitions.  If _PAGE_PRESENT is zero, the rest of the PTE is
+ * interpreted as swap information.  The remaining free bits are interpreted as
+ * swap type/offset tuple.  Rather than have the TLB fill handler test
+ * _PAGE_PRESENT, we're going to reserve the permissions bits and set them to
+ * all zeros for swap entries, which speeds up the miss handler at the cost of
+ * 3 bits of offset.  That trade-off can be revisited if necessary, but Hexagon
+ * processor architecture and target applications suggest a lot of TLB misses
+ * and not much swap space.
+ *
+ * Format of swap PTE:
+ *	bit	0:	Present (zero)
+ *	bits	1-5:	swap type (arch independent layer uses 5 bits max)
+ *	bits	6-9:	bits 3:0 of offset
+ *	bits	10-12:	effectively _PAGE_PROTNONE (all zero)
+ *	bits	13-31:  bits 22:4 of swap offset
+ *
+ * The split offset makes some of the following macros a little gnarly,
+ * but there's plenty of precedent for this sort of thing.
+ */
+
+/* Used for swap PTEs */
+#define __swp_type(swp_pte)		(((swp_pte).val >> 1) & 0x1f)
+
+#define __swp_offset(swp_pte) \
+	((((swp_pte).val >> 6) & 0xf) | (((swp_pte).val >> 9) & 0x7ffff0))
+
+#define __swp_entry(type, offset) \
+	((swp_entry_t)	{ \
+		((type << 1) | \
+		 ((offset & 0x7ffff0) << 9) | ((offset & 0xf) << 6)) })
+
+/*  Oh boy.  There are a lot of possible arch overrides found in this file.  */
+#include <asm-generic/pgtable.h>
+
+#endif