diff options
Diffstat (limited to 'linux-core/drm_compat.c')
| -rw-r--r-- | linux-core/drm_compat.c | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/linux-core/drm_compat.c b/linux-core/drm_compat.c new file mode 100644 index 00000000..b466f8bd --- /dev/null +++ b/linux-core/drm_compat.c @@ -0,0 +1,434 @@ +/************************************************************************** + * + * This kernel module 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; either version 2 of the + * License, or (at your option) any later version. + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + * + **************************************************************************/ +/* + * This code provides access to unexported mm kernel features. It is necessary + * to use the new DRM memory manager code with kernels that don't support it + * directly. + * + * Authors: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com> + * Linux kernel mm subsystem authors. + * (Most code taken from there). + */ + +#include "drmP.h" + +#if defined(CONFIG_X86) && (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)) + +/* + * These have bad performance in the AGP module for the indicated kernel versions. + */ + +int drm_map_page_into_agp(struct page *page) +{ + int i; + i = change_page_attr(page, 1, PAGE_KERNEL_NOCACHE); + /* Caller's responsibility to call global_flush_tlb() for + * performance reasons */ + return i; +} + +int drm_unmap_page_from_agp(struct page *page) +{ + int i; + i = change_page_attr(page, 1, PAGE_KERNEL); + /* Caller's responsibility to call global_flush_tlb() for + * performance reasons */ + return i; +} +#endif + + +#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)) + +/* + * The protection map was exported in 2.6.19 + */ + +pgprot_t vm_get_page_prot(unsigned long vm_flags) +{ +#ifdef MODULE + static pgprot_t drm_protection_map[16] = { + __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111, + __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111 + }; + + return drm_protection_map[vm_flags & 0x0F]; +#else + extern pgprot_t protection_map[]; + return protection_map[vm_flags & 0x0F]; +#endif +}; +#endif + + +#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)) + +/* + * vm code for kernels below 2,6,15 in which version a major vm write + * occured. This implement a simple straightforward + * version similar to what's going to be + * in kernel 2.6.20+? + */ + +static int drm_pte_is_clear(struct vm_area_struct *vma, + unsigned long addr) +{ + struct mm_struct *mm = vma->vm_mm; + int ret = 1; + pte_t *pte; + pmd_t *pmd; + pud_t *pud; + pgd_t *pgd; + + + spin_lock(&mm->page_table_lock); + pgd = pgd_offset(mm, addr); + if (pgd_none(*pgd)) + goto unlock; + pud = pud_offset(pgd, addr); + if (pud_none(*pud)) + goto unlock; + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) + goto unlock; + pte = pte_offset_map(pmd, addr); + if (!pte) + goto unlock; + ret = pte_none(*pte); + pte_unmap(pte); + unlock: + spin_unlock(&mm->page_table_lock); + return ret; +} + +int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, pgprot_t pgprot) +{ + int ret; + if (!drm_pte_is_clear(vma, addr)) + return -EBUSY; + + ret = io_remap_pfn_range(vma, addr, pfn, PAGE_SIZE, pgprot); + return ret; +} + +static struct { + spinlock_t lock; + struct page *dummy_page; + atomic_t present; +} drm_np_retry = +{SPIN_LOCK_UNLOCKED, NOPAGE_OOM, ATOMIC_INIT(0)}; + +struct page * get_nopage_retry(void) +{ + if (atomic_read(&drm_np_retry.present) == 0) { + struct page *page = alloc_page(GFP_KERNEL); + if (!page) + return NOPAGE_OOM; + spin_lock(&drm_np_retry.lock); + drm_np_retry.dummy_page = page; + atomic_set(&drm_np_retry.present,1); + spin_unlock(&drm_np_retry.lock); + } + get_page(drm_np_retry.dummy_page); + return drm_np_retry.dummy_page; +} + +void free_nopage_retry(void) +{ + if (atomic_read(&drm_np_retry.present) == 1) { + spin_lock(&drm_np_retry.lock); + __free_page(drm_np_retry.dummy_page); + drm_np_retry.dummy_page = NULL; + atomic_set(&drm_np_retry.present, 0); + spin_unlock(&drm_np_retry.lock); + } +} + +struct page *drm_vm_ttm_nopage(struct vm_area_struct *vma, + unsigned long address, + int *type) +{ + struct fault_data data; + + if (type) + *type = VM_FAULT_MINOR; + + data.address = address; + data.vma = vma; + drm_vm_ttm_fault(vma, &data); + switch (data.type) { + case VM_FAULT_OOM: + return NOPAGE_OOM; + case VM_FAULT_SIGBUS: + return NOPAGE_SIGBUS; + default: + break; + } + + return NOPAGE_REFAULT; +} + +#endif + +#ifdef DRM_ODD_MM_COMPAT + +/* + * VM compatibility code for 2.6.15-2.6.19(?). This code implements a complicated + * workaround for a single BUG statement in do_no_page in these versions. The + * tricky thing is that we need to take the mmap_sem in exclusive mode for _all_ + * vmas mapping the ttm, before dev->struct_mutex is taken. The way we do this is to + * check first take the dev->struct_mutex, and then trylock all mmap_sems. If this + * fails for a single mmap_sem, we have to release all sems and the dev->struct_mutex, + * release the cpu and retry. We also need to keep track of all vmas mapping the ttm. + * phew. + */ + +typedef struct p_mm_entry { + struct list_head head; + struct mm_struct *mm; + atomic_t refcount; + int locked; +} p_mm_entry_t; + +typedef struct vma_entry { + struct list_head head; + struct vm_area_struct *vma; +} vma_entry_t; + + +struct page *drm_vm_ttm_nopage(struct vm_area_struct *vma, + unsigned long address, + int *type) +{ + drm_local_map_t *map = (drm_local_map_t *) vma->vm_private_data; + unsigned long page_offset; + struct page *page; + drm_ttm_t *ttm; + drm_buffer_manager_t *bm; + drm_device_t *dev; + + /* + * FIXME: Check can't map aperture flag. + */ + + if (type) + *type = VM_FAULT_MINOR; + + if (!map) + return NOPAGE_OOM; + + if (address > vma->vm_end) + return NOPAGE_SIGBUS; + + ttm = (drm_ttm_t *) map->offset; + dev = ttm->dev; + mutex_lock(&dev->struct_mutex); + drm_fixup_ttm_caching(ttm); + BUG_ON(ttm->page_flags & DRM_TTM_PAGE_UNCACHED); + + bm = &dev->bm; + page_offset = (address - vma->vm_start) >> PAGE_SHIFT; + page = ttm->pages[page_offset]; + + if (!page) { + if (drm_alloc_memctl(PAGE_SIZE)) { + page = NOPAGE_OOM; + goto out; + } + page = ttm->pages[page_offset] = drm_alloc_gatt_pages(0); + if (!page) { + drm_free_memctl(PAGE_SIZE); + page = NOPAGE_OOM; + goto out; + } + ++bm->cur_pages; + SetPageLocked(page); + } + + get_page(page); + out: + mutex_unlock(&dev->struct_mutex); + return page; +} + + + + +int drm_ttm_map_bound(struct vm_area_struct *vma) +{ + drm_local_map_t *map = (drm_local_map_t *)vma->vm_private_data; + drm_ttm_t *ttm = (drm_ttm_t *) map->offset; + int ret = 0; + + if (ttm->page_flags & DRM_TTM_PAGE_UNCACHED) { + unsigned long pfn = ttm->aper_offset + + (ttm->be->aperture_base >> PAGE_SHIFT); + pgprot_t pgprot = drm_io_prot(ttm->be->drm_map_type, vma); + + ret = io_remap_pfn_range(vma, vma->vm_start, pfn, + vma->vm_end - vma->vm_start, + pgprot); + } + return ret; +} + + +int drm_ttm_add_vma(drm_ttm_t * ttm, struct vm_area_struct *vma) +{ + p_mm_entry_t *entry, *n_entry; + vma_entry_t *v_entry; + drm_local_map_t *map = (drm_local_map_t *) + vma->vm_private_data; + struct mm_struct *mm = vma->vm_mm; + + v_entry = drm_ctl_alloc(sizeof(*v_entry), DRM_MEM_TTM); + if (!v_entry) { + DRM_ERROR("Allocation of vma pointer entry failed\n"); + return -ENOMEM; + } + v_entry->vma = vma; + map->handle = (void *) v_entry; + list_add_tail(&v_entry->head, &ttm->vma_list); + + list_for_each_entry(entry, &ttm->p_mm_list, head) { + if (mm == entry->mm) { + atomic_inc(&entry->refcount); + return 0; + } else if ((unsigned long)mm < (unsigned long)entry->mm) ; + } + + n_entry = drm_ctl_alloc(sizeof(*n_entry), DRM_MEM_TTM); + if (!n_entry) { + DRM_ERROR("Allocation of process mm pointer entry failed\n"); + return -ENOMEM; + } + INIT_LIST_HEAD(&n_entry->head); + n_entry->mm = mm; + n_entry->locked = 0; + atomic_set(&n_entry->refcount, 0); + list_add_tail(&n_entry->head, &entry->head); + + return 0; +} + +void drm_ttm_delete_vma(drm_ttm_t * ttm, struct vm_area_struct *vma) +{ + p_mm_entry_t *entry, *n; + vma_entry_t *v_entry, *v_n; + int found = 0; + struct mm_struct *mm = vma->vm_mm; + + list_for_each_entry_safe(v_entry, v_n, &ttm->vma_list, head) { + if (v_entry->vma == vma) { + found = 1; + list_del(&v_entry->head); + drm_ctl_free(v_entry, sizeof(*v_entry), DRM_MEM_TTM); + break; + } + } + BUG_ON(!found); + + list_for_each_entry_safe(entry, n, &ttm->p_mm_list, head) { + if (mm == entry->mm) { + if (atomic_add_negative(-1, &entry->refcount)) { + list_del(&entry->head); + BUG_ON(entry->locked); + drm_ctl_free(entry, sizeof(*entry), DRM_MEM_TTM); + } + return; + } + } + BUG_ON(1); +} + + + +int drm_ttm_lock_mm(drm_ttm_t * ttm) +{ + p_mm_entry_t *entry; + int lock_ok = 1; + + list_for_each_entry(entry, &ttm->p_mm_list, head) { + BUG_ON(entry->locked); + if (!down_write_trylock(&entry->mm->mmap_sem)) { + lock_ok = 0; + break; + } + entry->locked = 1; + } + + if (lock_ok) + return 0; + + list_for_each_entry(entry, &ttm->p_mm_list, head) { + if (!entry->locked) + break; + up_write(&entry->mm->mmap_sem); + entry->locked = 0; + } + + /* + * Possible deadlock. Try again. Our callers should handle this + * and restart. + */ + + return -EAGAIN; +} + +void drm_ttm_unlock_mm(drm_ttm_t * ttm) +{ + p_mm_entry_t *entry; + + list_for_each_entry(entry, &ttm->p_mm_list, head) { + BUG_ON(!entry->locked); + up_write(&entry->mm->mmap_sem); + entry->locked = 0; + } +} + +int drm_ttm_remap_bound(drm_ttm_t *ttm) +{ + vma_entry_t *v_entry; + int ret = 0; + + list_for_each_entry(v_entry, &ttm->vma_list, head) { + ret = drm_ttm_map_bound(v_entry->vma); + if (ret) + break; + } + + drm_ttm_unlock_mm(ttm); + return ret; +} + +void drm_ttm_finish_unmap(drm_ttm_t *ttm) +{ + vma_entry_t *v_entry; + + if (!(ttm->page_flags & DRM_TTM_PAGE_UNCACHED)) + return; + + list_for_each_entry(v_entry, &ttm->vma_list, head) { + v_entry->vma->vm_flags &= ~VM_PFNMAP; + } + drm_ttm_unlock_mm(ttm); +} + +#endif + |