arch/tile: core support for Tilera 32-bit chips.

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 475 insertions, 0 deletions

diff --git a/arch/tile/include/asm/pgtable.h b/arch/tile/include/asm/pgtable.h
new file mode 100644
index 000000000000..beb1504e9c10
--- /dev/null
+++ b/arch/tile/include/asm/pgtable.h
@@ -0,0 +1,475 @@
+/*
+ * Copyright 2010 Tilera Corporation. 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
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * This file contains the functions and defines necessary to modify and use
+ * the TILE page table tree.
+ */
+
+#ifndef _ASM_TILE_PGTABLE_H
+#define _ASM_TILE_PGTABLE_H
+
+#include <hv/hypervisor.h>
+
+#ifndef __ASSEMBLY__
+
+#include <linux/bitops.h>
+#include <linux/threads.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <asm/processor.h>
+#include <asm/fixmap.h>
+#include <asm/system.h>
+
+struct mm_struct;
+struct vm_area_struct;
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+extern pgd_t swapper_pg_dir[];
+extern pgprot_t swapper_pgprot;
+extern struct kmem_cache *pgd_cache;
+extern spinlock_t pgd_lock;
+extern struct list_head pgd_list;
+
+/*
+ * The very last slots in the pgd_t are for addresses unusable by Linux
+ * (pgd_addr_invalid() returns true).  So we use them for the list structure.
+ * The x86 code we are modelled on uses the page->private/index fields
+ * (older 2.6 kernels) or the lru list (newer 2.6 kernels), but since
+ * our pgds are so much smaller than a page, it seems a waste to
+ * spend a whole page on each pgd.
+ */
+#define PGD_LIST_OFFSET \
+  ((PTRS_PER_PGD * sizeof(pgd_t)) - sizeof(struct list_head))
+#define pgd_to_list(pgd) \
+  ((struct list_head *)((char *)(pgd) + PGD_LIST_OFFSET))
+#define list_to_pgd(list) \
+  ((pgd_t *)((char *)(list) - PGD_LIST_OFFSET))
+
+extern void pgtable_cache_init(void);
+extern void paging_init(void);
+extern void set_page_homes(void);
+
+#define FIRST_USER_ADDRESS      0
+
+#define _PAGE_PRESENT           HV_PTE_PRESENT
+#define _PAGE_HUGE_PAGE         HV_PTE_PAGE
+#define _PAGE_READABLE          HV_PTE_READABLE
+#define _PAGE_WRITABLE          HV_PTE_WRITABLE
+#define _PAGE_EXECUTABLE        HV_PTE_EXECUTABLE
+#define _PAGE_ACCESSED          HV_PTE_ACCESSED
+#define _PAGE_DIRTY             HV_PTE_DIRTY
+#define _PAGE_GLOBAL            HV_PTE_GLOBAL
+#define _PAGE_USER              HV_PTE_USER
+
+/*
+ * All the "standard" bits.  Cache-control bits are managed elsewhere.
+ * This is used to test for valid level-2 page table pointers by checking
+ * all the bits, and to mask away the cache control bits for mprotect.
+ */
+#define _PAGE_ALL (\
+  _PAGE_PRESENT | \
+  _PAGE_HUGE_PAGE | \
+  _PAGE_READABLE | \
+  _PAGE_WRITABLE | \
+  _PAGE_EXECUTABLE | \
+  _PAGE_ACCESSED | \
+  _PAGE_DIRTY | \
+  _PAGE_GLOBAL | \
+  _PAGE_USER \
+)
+
+#define PAGE_NONE \
+        __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
+#define PAGE_SHARED \
+        __pgprot(_PAGE_PRESENT | _PAGE_READABLE | _PAGE_WRITABLE | \
+                 _PAGE_USER | _PAGE_ACCESSED)
+
+#define PAGE_SHARED_EXEC \
+        __pgprot(_PAGE_PRESENT | _PAGE_READABLE | _PAGE_WRITABLE | \
+                 _PAGE_EXECUTABLE | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_COPY_NOEXEC \
+        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_READABLE)
+#define PAGE_COPY_EXEC \
+        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | \
+                 _PAGE_READABLE | _PAGE_EXECUTABLE)
+#define PAGE_COPY \
+        PAGE_COPY_NOEXEC
+#define PAGE_READONLY \
+        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_READABLE)
+#define PAGE_READONLY_EXEC \
+        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | \
+                 _PAGE_READABLE | _PAGE_EXECUTABLE)
+
+#define _PAGE_KERNEL_RO \
+ (_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_READABLE | _PAGE_ACCESSED)
+#define _PAGE_KERNEL \
+ (_PAGE_KERNEL_RO | _PAGE_WRITABLE | _PAGE_DIRTY)
+#define _PAGE_KERNEL_EXEC       (_PAGE_KERNEL_RO | _PAGE_EXECUTABLE)
+
+#define PAGE_KERNEL             __pgprot(_PAGE_KERNEL)
+#define PAGE_KERNEL_RO          __pgprot(_PAGE_KERNEL_RO)
+#define PAGE_KERNEL_EXEC        __pgprot(_PAGE_KERNEL_EXEC)
+
+#define page_to_kpgprot(p) PAGE_KERNEL
+
+/*
+ * We could tighten these up, but for now writable or executable
+ * implies readable.
+ */
+#define __P000  PAGE_NONE
+#define __P001  PAGE_READONLY
+#define __P010  PAGE_COPY      /* this is write-only, which we won't support */
+#define __P011  PAGE_COPY
+#define __P100  PAGE_READONLY_EXEC
+#define __P101  PAGE_READONLY_EXEC
+#define __P110  PAGE_COPY_EXEC
+#define __P111  PAGE_COPY_EXEC
+
+#define __S000  PAGE_NONE
+#define __S001  PAGE_READONLY
+#define __S010  PAGE_SHARED
+#define __S011  PAGE_SHARED
+#define __S100  PAGE_READONLY_EXEC
+#define __S101  PAGE_READONLY_EXEC
+#define __S110  PAGE_SHARED_EXEC
+#define __S111  PAGE_SHARED_EXEC
+
+/*
+ * All the normal _PAGE_ALL bits are ignored for PMDs, except PAGE_PRESENT
+ * and PAGE_HUGE_PAGE, which must be one and zero, respectively.
+ * We set the ignored bits to zero.
+ */
+#define _PAGE_TABLE     _PAGE_PRESENT
+
+/* Inherit the caching flags from the old protection bits. */
+#define pgprot_modify(oldprot, newprot) \
+  (pgprot_t) { ((oldprot).val & ~_PAGE_ALL) | (newprot).val }
+
+/* Just setting the PFN to zero suffices. */
+#define pte_pgprot(x) hv_pte_set_pfn((x), 0)
+
+/*
+ * For PTEs and PDEs, we must clear the Present bit first when
+ * clearing a page table entry, so clear the bottom half first and
+ * enforce ordering with a barrier.
+ */
+static inline void __pte_clear(pte_t *ptep)
+{
+#ifdef __tilegx__
+        ptep->val = 0;
+#else
+        u32 *tmp = (u32 *)ptep;
+        tmp[0] = 0;
+        barrier();
+        tmp[1] = 0;
+#endif
+}
+#define pte_clear(mm, addr, ptep) __pte_clear(ptep)
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+#define pte_present hv_pte_get_present
+#define pte_user hv_pte_get_user
+#define pte_read hv_pte_get_readable
+#define pte_dirty hv_pte_get_dirty
+#define pte_young hv_pte_get_accessed
+#define pte_write hv_pte_get_writable
+#define pte_exec hv_pte_get_executable
+#define pte_huge hv_pte_get_page
+#define pte_rdprotect hv_pte_clear_readable
+#define pte_exprotect hv_pte_clear_executable
+#define pte_mkclean hv_pte_clear_dirty
+#define pte_mkold hv_pte_clear_accessed
+#define pte_wrprotect hv_pte_clear_writable
+#define pte_mksmall hv_pte_clear_page
+#define pte_mkread hv_pte_set_readable
+#define pte_mkexec hv_pte_set_executable
+#define pte_mkdirty hv_pte_set_dirty
+#define pte_mkyoung hv_pte_set_accessed
+#define pte_mkwrite hv_pte_set_writable
+#define pte_mkhuge hv_pte_set_page
+
+#define pte_special(pte) 0
+#define pte_mkspecial(pte) (pte)
+
+/*
+ * Use some spare bits in the PTE for user-caching tags.
+ */
+#define pte_set_forcecache hv_pte_set_client0
+#define pte_get_forcecache hv_pte_get_client0
+#define pte_clear_forcecache hv_pte_clear_client0
+#define pte_set_anyhome hv_pte_set_client1
+#define pte_get_anyhome hv_pte_get_client1
+#define pte_clear_anyhome hv_pte_clear_client1
+
+/*
+ * A migrating PTE has PAGE_PRESENT clear but all the other bits preserved.
+ */
+#define pte_migrating hv_pte_get_migrating
+#define pte_mkmigrate(x) hv_pte_set_migrating(hv_pte_clear_present(x))
+#define pte_donemigrate(x) hv_pte_set_present(hv_pte_clear_migrating(x))
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte 0x%016llx.\n", __FILE__, __LINE__, pte_val(e))
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd 0x%016llx.\n", __FILE__, __LINE__, pgd_val(e))
+
+/*
+ * set_pte_order() sets the given PTE and also sanity-checks the
+ * requested PTE against the page homecaching.  Unspecified parts
+ * of the PTE are filled in when it is written to memory, i.e. all
+ * caching attributes if "!forcecache", or the home cpu if "anyhome".
+ */
+extern void set_pte_order(pte_t *ptep, pte_t pte, int order);
+
+#define set_pte(ptep, pteval) set_pte_order(ptep, pteval, 0)
+#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
+#define set_pte_atomic(pteptr, pteval) set_pte(pteptr, pteval)
+
+#define pte_page(x)             pfn_to_page(pte_pfn(x))
+
+static inline int pte_none(pte_t pte)
+{
+        return !pte.val;
+}
+
+static inline unsigned long pte_pfn(pte_t pte)
+{
+        return hv_pte_get_pfn(pte);
+}
+
+/* Set or get the remote cache cpu in a pgprot with remote caching. */
+extern pgprot_t set_remote_cache_cpu(pgprot_t prot, int cpu);
+extern int get_remote_cache_cpu(pgprot_t prot);
+
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
+{
+        return hv_pte_set_pfn(prot, pfn);
+}
+
+/* Support for priority mappings. */
+extern void start_mm_caching(struct mm_struct *mm);
+extern void check_mm_caching(struct mm_struct *prev, struct mm_struct *next);
+
+/*
+ * Support non-linear file mappings (see sys_remap_file_pages).
+ * This is defined by CLIENT1 set but CLIENT0 and _PAGE_PRESENT clear, and the
+ * file offset in the 32 high bits.
+ */
+#define _PAGE_FILE        HV_PTE_CLIENT1
+#define PTE_FILE_MAX_BITS 32
+#define pte_file(pte)     (hv_pte_get_client1(pte) && !hv_pte_get_client0(pte))
+#define pte_to_pgoff(pte) ((pte).val >> 32)
+#define pgoff_to_pte(off) ((pte_t) { (((long long)(off)) << 32) | _PAGE_FILE })
+
+/*
+ * Encode and de-code a swap entry (see <linux/swapops.h>).
+ * We put the swap file type+offset in the 32 high bits;
+ * I believe we can just leave the low bits clear.
+ */
+#define __swp_type(swp)         ((swp).val & 0x1f)
+#define __swp_offset(swp)       ((swp).val >> 5)
+#define __swp_entry(type, off)  ((swp_entry_t) { (type) | ((off) << 5) })
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).val >> 32 })
+#define __swp_entry_to_pte(swp) ((pte_t) { (((long long) ((swp).val)) << 32) })
+
+/*
+ * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
+ *
+ *  dst - pointer to pgd range anwhere on a pgd page
+ *  src - ""
+ *  count - the number of pgds to copy.
+ *
+ * dst and src can be on the same page, but the range must not overlap,
+ * and must not cross a page boundary.
+ */
+static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
+{
+       memcpy(dst, src, count * sizeof(pgd_t));
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+
+#define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
+
+/*
+ * If we are doing an mprotect(), just accept the new vma->vm_page_prot
+ * value and combine it with the PFN from the old PTE to get a new PTE.
+ */
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+        return pfn_pte(hv_pte_get_pfn(pte), newprot);
+}
+
+/*
+ * The pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
+ *
+ * This macro returns the index of the entry in the pgd page which would
+ * control the given virtual address.
+ */
+#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
+
+/*
+ * pgd_offset() returns a (pgd_t *)
+ * pgd_index() is used get the offset into the pgd page's array of pgd_t's.
+ */
+#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
+
+/*
+ * A shortcut which implies the use of the kernel's pgd, instead
+ * of a process's.
+ */
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+
+#if defined(CONFIG_HIGHPTE)
+extern pte_t *_pte_offset_map(pmd_t *, unsigned long address, enum km_type);
+#define pte_offset_map(dir, address) \
+        _pte_offset_map(dir, address, KM_PTE0)
+#define pte_offset_map_nested(dir, address) \
+        _pte_offset_map(dir, address, KM_PTE1)
+#define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
+#define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
+#else
+#define pte_offset_map(dir, address) pte_offset_kernel(dir, address)
+#define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
+#define pte_unmap(pte) do { } while (0)
+#define pte_unmap_nested(pte) do { } while (0)
+#endif
+
+/* Clear a non-executable kernel PTE and flush it from the TLB. */
+#define kpte_clear_flush(ptep, vaddr)           \
+do {                                            \
+        pte_clear(&init_mm, (vaddr), (ptep));   \
+        local_flush_tlb_page(FLUSH_NONEXEC, (vaddr), PAGE_SIZE); \
+} while (0)
+
+/*
+ * The kernel page tables contain what we need, and we flush when we
+ * change specific page table entries.
+ */
+#define update_mmu_cache(vma, address, pte) do { } while (0)
+
+#ifdef CONFIG_FLATMEM
+#define kern_addr_valid(addr)   (1)
+#endif /* CONFIG_FLATMEM */
+
+#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)         \
+                remap_pfn_range(vma, vaddr, pfn, size, prot)
+
+extern void vmalloc_sync_all(void);
+
+#endif /* !__ASSEMBLY__ */
+
+#ifdef __tilegx__
+#include <asm/pgtable_64.h>
+#else
+#include <asm/pgtable_32.h>
+#endif
+
+#ifndef __ASSEMBLY__
+
+static inline int pmd_none(pmd_t pmd)
+{
+        /*
+         * Only check low word on 32-bit platforms, since it might be
+         * out of sync with upper half.
+         */
+        return (unsigned long)pmd_val(pmd) == 0;
+}
+
+static inline int pmd_present(pmd_t pmd)
+{
+        return pmd_val(pmd) & _PAGE_PRESENT;
+}
+
+static inline int pmd_bad(pmd_t pmd)
+{
+        return ((pmd_val(pmd) & _PAGE_ALL) != _PAGE_TABLE);
+}
+
+static inline unsigned long pages_to_mb(unsigned long npg)
+{
+        return npg >> (20 - PAGE_SHIFT);
+}
+
+/*
+ * The pmd can be thought of an array like this: pmd_t[PTRS_PER_PMD]
+ *
+ * This function returns the index of the entry in the pmd which would
+ * control the given virtual address.
+ */
+static inline unsigned long pmd_index(unsigned long address)
+{
+        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
+}
+
+/*
+ * A given kernel pmd_t maps to a specific virtual address (either a
+ * kernel huge page or a kernel pte_t table).  Since kernel pte_t
+ * tables can be aligned at sub-page granularity, this function can
+ * return non-page-aligned pointers, despite its name.
+ */
+static inline unsigned long pmd_page_vaddr(pmd_t pmd)
+{
+        phys_addr_t pa =
+                (phys_addr_t)pmd_ptfn(pmd) << HV_LOG2_PAGE_TABLE_ALIGN;
+        return (unsigned long)__va(pa);
+}
+
+/*
+ * A pmd_t points to the base of a huge page or to a pte_t array.
+ * If a pte_t array, since we can have multiple per page, we don't
+ * have a one-to-one mapping of pmd_t's to pages.  However, this is
+ * OK for pte_lockptr(), since we just end up with potentially one
+ * lock being used for several pte_t arrays.
+ */
+#define pmd_page(pmd) pfn_to_page(HV_PTFN_TO_PFN(pmd_ptfn(pmd)))
+
+/*
+ * The pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
+ *
+ * This macro returns the index of the entry in the pte page which would
+ * control the given virtual address.
+ */
+static inline unsigned long pte_index(unsigned long address)
+{
+        return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
+}
+
+static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
+{
+       return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
+}
+
+static inline int pmd_huge_page(pmd_t pmd)
+{
+        return pmd_val(pmd) & _PAGE_HUGE_PAGE;
+}
+
+#include <asm-generic/pgtable.h>
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_TILE_PGTABLE_H */