[PATCH 1/7] Add various hugetlb arm high level hooks
Bill Carson
bill4carson at gmail.com
Mon Feb 13 04:44:22 EST 2012
Signed-off-by: Bill Carson <bill4carson at gmail.com>
---
arch/arm/include/asm/hugetlb.h | 178 ++++++++++++++++++++++++++++++++++++++++
arch/arm/include/asm/page.h | 15 ++++
arch/arm/mm/hugetlb.c | 132 +++++++++++++++++++++++++++++
3 files changed, 325 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/include/asm/hugetlb.h
create mode 100644 arch/arm/mm/hugetlb.c
diff --git a/arch/arm/include/asm/hugetlb.h b/arch/arm/include/asm/hugetlb.h
new file mode 100644
index 0000000..3c34528
--- /dev/null
+++ b/arch/arm/include/asm/hugetlb.h
@@ -0,0 +1,178 @@
+/*
+ * hugetlb.h, ARM Huge Tlb Page support.
+ *
+ * Copyright (c) Bill Carson
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#ifndef __ASM_HUGETLB_H
+#define __ASM_HUGETLB_H
+
+#include <asm/page.h>
+#include <asm/pgtable-2level.h>
+#include <asm/tlb.h>
+
+
+/* 2M and 16M hugepage linux ptes are stored in mmu_context_t->huge_linux_pte
+ *
+ * 2M hugepage
+ * ===========
+ * one huge linux pte caters to two HW ptes,
+ *
+ * 16M hugepage
+ * ============
+ * one huge linux pte caters for sixteen HW ptes,
+ *
+ * The number of huge linux ptes depends on PAGE_OFFSET configuration
+ * which is defined as following:
+ */
+#define HUGE_LINUX_PTE_COUNT ( PAGE_OFFSET >> HPAGE_SHIFT)
+#define HUGE_LINUX_PTE_SIZE (HUGE_LINUX_PTE_COUNT * sizeof(pte_t *))
+#define HUGE_LINUX_PTE_INDEX(addr) (addr >> HPAGE_SHIFT)
+
+static inline int is_hugepage_only_range(struct mm_struct *mm,
+ unsigned long addr,
+ unsigned long len)
+{
+ return 0;
+}
+
+static inline int prepare_hugepage_range(struct file *file,
+ unsigned long addr,
+ unsigned long len)
+{
+ struct hstate *h = hstate_file(file);
+ /* addr/len should be aligned with huge page size */
+ if (len & ~huge_page_mask(h))
+ return -EINVAL;
+ if (addr & ~huge_page_mask(h))
+ return -EINVAL;
+
+ return 0;
+}
+
+static inline void hugetlb_prefault_arch_hook(struct mm_struct *mm)
+{
+}
+
+static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+}
+
+static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *linuxpte = mm->context.huge_linux_pte;
+
+ BUG_ON(linuxpte == NULL);
+ BUG_ON(HUGE_LINUX_PTE_INDEX(addr) >= HUGE_LINUX_PTE_COUNT);
+ BUG_ON(ptep != &linuxpte[HUGE_LINUX_PTE_INDEX(addr)]);
+
+ /* set huge linux pte first */
+ *ptep = pte;
+
+ /* then set hardware pte */
+ addr &= HPAGE_MASK;
+ pgd = pgd_offset(mm, addr);
+ pud = pud_offset(pgd, addr);
+ pmd = pmd_offset(pud, addr);
+ set_hugepte_at(mm, addr, pmd, pte);
+}
+
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ pte_t pte = *ptep;
+ pte_t fake = L_PTE_YOUNG;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ /* clear linux pte */
+ *ptep = 0;
+
+ /* let set_hugepte_at clear HW entry */
+ addr &= HPAGE_MASK;
+ pgd = pgd_offset(mm, addr);
+ pud = pud_offset(pgd, addr);
+ pmd = pmd_offset(pud, addr);
+ set_hugepte_at(mm, addr, pmd, fake);
+ return pte;
+}
+
+static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ if (HPAGE_SHIFT == SUPERSECTION_SHIFT)
+ flush_tlb_page(vma, addr & SUPERSECTION_MASK);
+ else {
+ flush_tlb_page(vma, addr & SECTION_MASK);
+ flush_tlb_page(vma, (addr & SECTION_MASK)^0x100000);
+ }
+}
+
+static inline int huge_pte_none(pte_t pte)
+{
+ return pte_none(pte);
+}
+
+static inline pte_t huge_pte_wrprotect(pte_t pte)
+{
+ return pte_wrprotect(pte);
+}
+
+static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ pte_t old_pte = *ptep;
+ set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
+}
+
+static inline pte_t huge_ptep_get(pte_t *ptep)
+{
+ return *ptep;
+}
+
+static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr,
+ pte_t *ptep, pte_t pte,
+ int dirty)
+{
+ int changed = !pte_same(huge_ptep_get(ptep), pte);
+ if (changed) {
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+ huge_ptep_clear_flush(vma, addr, &pte);
+ }
+
+ return changed;
+}
+
+static inline int arch_prepare_hugepage(struct page *page)
+{
+ return 0;
+}
+
+static inline void arch_release_hugepage(struct page *page)
+{
+}
+
+#endif /* __ASM_HUGETLB_H */
+
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h
index 97b440c..3e6769a 100644
--- a/arch/arm/include/asm/page.h
+++ b/arch/arm/include/asm/page.h
@@ -15,6 +15,21 @@
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
+#ifdef CONFIG_HUGEPAGE_SIZE_2MB
+/* we have 2MB hugepage for two 1MB section mapping */
+#define HPAGE_SHIFT (SECTION_SHIFT + 1)
+#define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK (~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
+#endif
+
+#ifdef CONFIG_HUGEPAGE_SIZE_16MB
+#define HPAGE_SHIFT SUPERSECTION_SHIFT
+#define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT)
+#define HPAGE_MASK (~(HPAGE_SIZE - 1))
+#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
+#endif
+
#ifndef __ASSEMBLY__
#ifndef CONFIG_MMU
diff --git a/arch/arm/mm/hugetlb.c b/arch/arm/mm/hugetlb.c
new file mode 100644
index 0000000..165bd8f
--- /dev/null
+++ b/arch/arm/mm/hugetlb.c
@@ -0,0 +1,132 @@
+/*
+ * hugetlb.c, ARM Huge Tlb Page support.
+ *
+ * Copyright (c) Bill Carson
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/hugetlb.h>
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
+ unsigned long sz)
+{
+ pte_t *linuxpte = mm->context.huge_linux_pte;
+ int index;
+
+ if (linuxpte == NULL) {
+ linuxpte = kzalloc(HUGE_LINUX_PTE_SIZE, GFP_ATOMIC);
+ if (linuxpte == NULL) {
+ printk(KERN_ERR "Cannot allocate memory for huge linux pte\n");
+ return NULL;
+ }
+ mm->context.huge_linux_pte = linuxpte;
+ }
+ /* huge page mapping only cover user space address */
+ BUG_ON(HUGE_LINUX_PTE_INDEX(addr) >= HUGE_LINUX_PTE_COUNT);
+ index = HUGE_LINUX_PTE_INDEX(addr);
+ return &linuxpte[HUGE_LINUX_PTE_INDEX(addr)];
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd = NULL;
+ pte_t *linuxpte = mm->context.huge_linux_pte;
+
+ /* check this mapping exist at pmd level */
+ pgd = pgd_offset(mm, addr);
+ if (pgd_present(*pgd)) {
+ pud = pud_offset(pgd, addr);
+ pmd = pmd_offset(pud, addr);
+ if (!pmd_present(*pmd))
+ return NULL;
+ }
+
+ BUG_ON(HUGE_LINUX_PTE_INDEX(addr) >= HUGE_LINUX_PTE_COUNT);
+ BUG_ON((*pmd & PMD_TYPE_MASK) != PMD_TYPE_SECT);
+ return &linuxpte[HUGE_LINUX_PTE_INDEX(addr)];
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return (pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_SECT;
+}
+
+int pud_huge(pud_t pud)
+{
+ return 0; } struct page * follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
+{
+ struct page *page = NULL;
+ unsigned long pfn;
+
+ BUG_ON((pmd_val(*pmd) & PMD_TYPE_MASK) != PMD_TYPE_SECT);
+ pfn = ((pmd_val(*pmd) & HPAGE_MASK) >> PAGE_SHIFT);
+ page = pfn_to_page(pfn);
+ return page;
+}
+
+static int __init add_huge_page_size(unsigned long long size)
+{
+ int shift = __ffs(size);
+ u32 mmfr3 = 0;
+
+ /* Check that it is a page size supported by the hardware and
+ * that it fits within pagetable and slice limits. */
+ if (!is_power_of_2(size) || (shift != HPAGE_SHIFT))
+ return -EINVAL;
+
+ /* If user wants super-section support, then check if our cpu
+ * has this feature supported in ID_MMFR3 */
+ if (shift == SUPERSECTION_SHIFT) {
+ __asm__("mrc p15, 0, %0, c0, c1, 7\n" : "=r" (mmfr3));
+ if (mmfr3 & 0xF0000000) {
+ printk("Super-Section is NOT supported by this CPU, mmfr3:0x%x\n", mmfr3);
+ return -EINVAL;
+ }
+ }
+
+ /* Return if huge page size has already been setup */
+ if (size_to_hstate(size))
+ return 0;
+
+ hugetlb_add_hstate(shift - PAGE_SHIFT);
+ return 0;
+}
+
+static int __init hugepage_setup_sz(char *str)
+{
+ unsigned long long size;
+
+ size = memparse(str, &str);
+ if (add_huge_page_size(size) != 0)
+ printk(KERN_WARNING "Invalid huge page size specified(%llu)\n",
+ size);
+
+ return 1;
+}
+__setup("hugepagesz=", hugepage_setup_sz);
--
1.7.1
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