drm/linux-core/drm_compat.c

459 lines
10 KiB
C

/**************************************************************************
*
* 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 2.6.19+
* Kernels below 2.6.15 use nopage whereas 2.6.19 and upwards use
* nopfn.
*/
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_bo_vm_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_bo_vm_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
#if !defined(DRM_FULL_MM_COMPAT) && \
((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)) || \
(LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)))
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)
{
int ret;
if (!drm_pte_is_clear(vma, addr))
return -EBUSY;
ret = io_remap_pfn_range(vma, addr, pfn, PAGE_SIZE, vma->vm_page_prot);
return ret;
}
#endif
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19) && !defined(DRM_FULL_MM_COMPAT))
/**
* While waiting for the fault() handler to appear in
* we accomplish approximately
* the same wrapping it with nopfn.
*/
unsigned long drm_bo_vm_nopfn(struct vm_area_struct * vma,
unsigned long address)
{
struct fault_data data;
data.address = address;
(void) drm_bo_vm_fault(vma, &data);
if (data.type == VM_FAULT_OOM)
return NOPFN_OOM;
else if (data.type == VM_FAULT_SIGBUS)
return NOPFN_SIGBUS;
/*
* pfn already set.
*/
return 0;
}
#endif
#ifdef DRM_ODD_MM_COMPAT
/*
* VM compatibility code for 2.6.15-2.6.18. 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_bo_vm_nopage(struct vm_area_struct *vma,
unsigned long address,
int *type)
{
drm_buffer_object_t *bo = (drm_buffer_object_t *) vma->vm_private_data;
unsigned long page_offset;
struct page *page;
drm_ttm_t *ttm;
drm_device_t *dev;
mutex_lock(&bo->mutex);
if (type)
*type = VM_FAULT_MINOR;
if (address > vma->vm_end) {
page = NOPAGE_SIGBUS;
goto out_unlock;
}
dev = bo->dev;
if (drm_mem_reg_is_pci(dev, &bo->mem)) {
DRM_ERROR("Invalid compat nopage.\n");
page = NOPAGE_SIGBUS;
goto out_unlock;
}
ttm = bo->ttm;
drm_ttm_fixup_caching(ttm);
page_offset = (address - vma->vm_start) >> PAGE_SHIFT;
page = drm_ttm_get_page(ttm, page_offset);
if (!page) {
page = NOPAGE_OOM;
goto out_unlock;
}
get_page(page);
out_unlock:
mutex_unlock(&bo->mutex);
return page;
}
int drm_bo_map_bound(struct vm_area_struct *vma)
{
drm_buffer_object_t *bo = (drm_buffer_object_t *)vma->vm_private_data;
int ret = 0;
unsigned long bus_base;
unsigned long bus_offset;
unsigned long bus_size;
ret = drm_bo_pci_offset(bo->dev, &bo->mem, &bus_base,
&bus_offset, &bus_size);
BUG_ON(ret);
if (bus_size) {
drm_mem_type_manager_t *man = &bo->dev->bm.man[bo->mem.mem_type];
unsigned long pfn = (bus_base + bus_offset) >> PAGE_SHIFT;
pgprot_t pgprot = drm_io_prot(man->drm_bus_maptype, vma);
ret = io_remap_pfn_range(vma, vma->vm_start, pfn,
vma->vm_end - vma->vm_start,
pgprot);
}
return ret;
}
int drm_bo_add_vma(drm_buffer_object_t * bo, struct vm_area_struct *vma)
{
p_mm_entry_t *entry, *n_entry;
vma_entry_t *v_entry;
struct mm_struct *mm = vma->vm_mm;
v_entry = drm_ctl_alloc(sizeof(*v_entry), DRM_MEM_BUFOBJ);
if (!v_entry) {
DRM_ERROR("Allocation of vma pointer entry failed\n");
return -ENOMEM;
}
v_entry->vma = vma;
list_add_tail(&v_entry->head, &bo->vma_list);
list_for_each_entry(entry, &bo->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_BUFOBJ);
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_bo_delete_vma(drm_buffer_object_t * bo, 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, &bo->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_BUFOBJ);
break;
}
}
BUG_ON(!found);
list_for_each_entry_safe(entry, n, &bo->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_BUFOBJ);
}
return;
}
}
BUG_ON(1);
}
int drm_bo_lock_kmm(drm_buffer_object_t * bo)
{
p_mm_entry_t *entry;
int lock_ok = 1;
list_for_each_entry(entry, &bo->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, &bo->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_bo_unlock_kmm(drm_buffer_object_t * bo)
{
p_mm_entry_t *entry;
list_for_each_entry(entry, &bo->p_mm_list, head) {
BUG_ON(!entry->locked);
up_write(&entry->mm->mmap_sem);
entry->locked = 0;
}
}
int drm_bo_remap_bound(drm_buffer_object_t *bo)
{
vma_entry_t *v_entry;
int ret = 0;
if (drm_mem_reg_is_pci(bo->dev, &bo->mem)) {
list_for_each_entry(v_entry, &bo->vma_list, head) {
ret = drm_bo_map_bound(v_entry->vma);
if (ret)
break;
}
}
return ret;
}
void drm_bo_finish_unmap(drm_buffer_object_t *bo)
{
vma_entry_t *v_entry;
list_for_each_entry(v_entry, &bo->vma_list, head) {
v_entry->vma->vm_flags &= ~VM_PFNMAP;
}
}
#endif