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diff --git a/xorg-server/exa/exa_offscreen.c b/xorg-server/exa/exa_offscreen.c
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+/*
+ * Copyright © 2003 Anders Carlsson
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of Anders Carlsson not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission. Anders Carlsson makes no
+ * representations about the suitability of this software for any purpose. It
+ * is provided "as is" without express or implied warranty.
+ *
+ * ANDERS CARLSSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL ANDERS CARLSSON BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/** @file
+ * This allocator allocates blocks of memory by maintaining a list of areas.
+ * When allocating, the contiguous block of areas with the minimum eviction
+ * cost is found and evicted in order to make room for the new allocation.
+ */
+
+#include "exa_priv.h"
+
+#include <limits.h>
+#include <assert.h>
+#include <stdlib.h>
+
+#if DEBUG_OFFSCREEN
+#define DBG_OFFSCREEN(a) ErrorF a
+#else
+#define DBG_OFFSCREEN(a)
+#endif
+
+#if DEBUG_OFFSCREEN
+static void
+ExaOffscreenValidate (ScreenPtr pScreen)
+{
+ ExaScreenPriv (pScreen);
+ ExaOffscreenArea *prev = 0, *area;
+
+ assert (pExaScr->info->offScreenAreas->base_offset ==
+ pExaScr->info->offScreenBase);
+ for (area = pExaScr->info->offScreenAreas; area; area = area->next)
+ {
+ assert (area->offset >= area->base_offset &&
+ area->offset < (area->base_offset + area->size));
+ if (prev)
+ assert (prev->base_offset + prev->size == area->base_offset);
+ prev = area;
+ }
+ assert (prev->base_offset + prev->size == pExaScr->info->memorySize);
+}
+#else
+#define ExaOffscreenValidate(s)
+#endif
+
+static ExaOffscreenArea *
+ExaOffscreenKickOut (ScreenPtr pScreen, ExaOffscreenArea *area)
+{
+ if (area->save)
+ (*area->save) (pScreen, area);
+ return exaOffscreenFree (pScreen, area);
+}
+
+static void
+exaUpdateEvictionCost(ExaOffscreenArea *area, unsigned offScreenCounter)
+{
+ unsigned age;
+
+ if (area->state == ExaOffscreenAvail)
+ return;
+
+ age = offScreenCounter - area->last_use;
+
+ /* This is unlikely to happen, but could result in a division by zero... */
+ if (age > (UINT_MAX / 2)) {
+ age = UINT_MAX / 2;
+ area->last_use = offScreenCounter - age;
+ }
+
+ area->eviction_cost = area->size / age;
+}
+
+static ExaOffscreenArea *
+exaFindAreaToEvict(ExaScreenPrivPtr pExaScr, int size, int align)
+{
+ ExaOffscreenArea *begin, *end, *best;
+ unsigned cost, best_cost;
+ int avail, real_size, tmp;
+
+ best_cost = UINT_MAX;
+ begin = end = pExaScr->info->offScreenAreas;
+ avail = 0;
+ cost = 0;
+ best = 0;
+
+ while (end != NULL)
+ {
+ restart:
+ while (begin != NULL && begin->state == ExaOffscreenLocked)
+ begin = end = begin->next;
+
+ if (begin == NULL)
+ break;
+
+ /* adjust size needed to account for alignment loss for this area */
+ real_size = size;
+ tmp = begin->base_offset % align;
+ if (tmp)
+ real_size += (align - tmp);
+
+ while (avail < real_size && end != NULL)
+ {
+ if (end->state == ExaOffscreenLocked) {
+ /* Can't more room here, restart after this locked area */
+ avail = 0;
+ cost = 0;
+ begin = end;
+ goto restart;
+ }
+ avail += end->size;
+ exaUpdateEvictionCost(end, pExaScr->offScreenCounter);
+ cost += end->eviction_cost;
+ end = end->next;
+ }
+
+ /* Check the cost, update best */
+ if (avail >= real_size && cost < best_cost) {
+ best = begin;
+ best_cost = cost;
+ }
+
+ avail -= begin->size;
+ cost -= begin->eviction_cost;
+ begin = begin->next;
+ }
+
+ return best;
+}
+
+/**
+ * exaOffscreenAlloc allocates offscreen memory
+ *
+ * @param pScreen current screen
+ * @param size size in bytes of the allocation
+ * @param align byte alignment requirement for the offset of the allocated area
+ * @param locked whether the allocated area is locked and can't be kicked out
+ * @param save callback for when the area is evicted from memory
+ * @param privdata private data for the save callback.
+ *
+ * Allocates offscreen memory from the device associated with pScreen. size
+ * and align deteremine where and how large the allocated area is, and locked
+ * will mark whether it should be held in card memory. privdata may be any
+ * pointer for the save callback when the area is removed.
+ *
+ * Note that locked areas do get evicted on VT switch unless the driver
+ * requested version 2.1 or newer behavior. In that case, the save callback is
+ * still called.
+ */
+ExaOffscreenArea *
+exaOffscreenAlloc (ScreenPtr pScreen, int size, int align,
+ Bool locked,
+ ExaOffscreenSaveProc save,
+ pointer privData)
+{
+ ExaOffscreenArea *area;
+ ExaScreenPriv (pScreen);
+ int tmp, real_size = 0;
+#if DEBUG_OFFSCREEN
+ static int number = 0;
+ ErrorF("================= ============ allocating a new pixmap %d\n", ++number);
+#endif
+
+ ExaOffscreenValidate (pScreen);
+ if (!align)
+ align = 1;
+
+ if (!size)
+ {
+ DBG_OFFSCREEN (("Alloc 0x%x -> EMPTY\n", size));
+ return NULL;
+ }
+
+ /* throw out requests that cannot fit */
+ if (size > (pExaScr->info->memorySize - pExaScr->info->offScreenBase))
+ {
+ DBG_OFFSCREEN (("Alloc 0x%x vs (0x%lx) -> TOBIG\n", size,
+ pExaScr->info->memorySize -
+ pExaScr->info->offScreenBase));
+ return NULL;
+ }
+
+ /* Try to find a free space that'll fit. */
+ for (area = pExaScr->info->offScreenAreas; area; area = area->next)
+ {
+ /* skip allocated areas */
+ if (area->state != ExaOffscreenAvail)
+ continue;
+
+ /* adjust size to match alignment requirement */
+ real_size = size;
+ tmp = area->base_offset % align;
+ if (tmp)
+ real_size += (align - tmp);
+
+ /* does it fit? */
+ if (real_size <= area->size)
+ break;
+ }
+
+ if (!area)
+ {
+ area = exaFindAreaToEvict(pExaScr, size, align);
+
+ if (!area)
+ {
+ DBG_OFFSCREEN (("Alloc 0x%x -> NOSPACE\n", size));
+ /* Could not allocate memory */
+ ExaOffscreenValidate (pScreen);
+ return NULL;
+ }
+
+ /* adjust size needed to account for alignment loss for this area */
+ real_size = size;
+ tmp = area->base_offset % align;
+ if (tmp)
+ real_size += (align - tmp);
+
+ /*
+ * Kick out first area if in use
+ */
+ if (area->state != ExaOffscreenAvail)
+ area = ExaOffscreenKickOut (pScreen, area);
+ /*
+ * Now get the system to merge the other needed areas together
+ */
+ while (area->size < real_size)
+ {
+ assert (area->next && area->next->state == ExaOffscreenRemovable);
+ (void) ExaOffscreenKickOut (pScreen, area->next);
+ }
+ }
+
+ /* save extra space in new area */
+ if (real_size < area->size)
+ {
+ ExaOffscreenArea *new_area = xalloc (sizeof (ExaOffscreenArea));
+ if (!new_area)
+ return NULL;
+ new_area->base_offset = area->base_offset + real_size;
+ new_area->offset = new_area->base_offset;
+ new_area->size = area->size - real_size;
+ new_area->state = ExaOffscreenAvail;
+ new_area->save = NULL;
+ new_area->last_use = 0;
+ new_area->eviction_cost = 0;
+ new_area->next = area->next;
+ area->next = new_area;
+ area->size = real_size;
+ }
+ /*
+ * Mark this area as in use
+ */
+ if (locked)
+ area->state = ExaOffscreenLocked;
+ else
+ area->state = ExaOffscreenRemovable;
+ area->privData = privData;
+ area->save = save;
+ area->last_use = pExaScr->offScreenCounter++;
+ area->offset = (area->base_offset + align - 1);
+ area->offset -= area->offset % align;
+
+ ExaOffscreenValidate (pScreen);
+
+ DBG_OFFSCREEN (("Alloc 0x%x -> 0x%x (0x%x)\n", size,
+ area->base_offset, area->offset));
+ return area;
+}
+
+/**
+ * Ejects all offscreen areas, and uninitializes the offscreen memory manager.
+ */
+void
+ExaOffscreenSwapOut (ScreenPtr pScreen)
+{
+ ExaScreenPriv (pScreen);
+
+ ExaOffscreenValidate (pScreen);
+ /* loop until a single free area spans the space */
+ for (;;)
+ {
+ ExaOffscreenArea *area = pExaScr->info->offScreenAreas;
+
+ if (!area)
+ break;
+ if (area->state == ExaOffscreenAvail)
+ {
+ area = area->next;
+ if (!area)
+ break;
+ }
+ assert (area->state != ExaOffscreenAvail);
+ (void) ExaOffscreenKickOut (pScreen, area);
+ ExaOffscreenValidate (pScreen);
+ }
+ ExaOffscreenValidate (pScreen);
+ ExaOffscreenFini (pScreen);
+}
+
+/** Ejects all pixmaps managed by EXA. */
+static void
+ExaOffscreenEjectPixmaps (ScreenPtr pScreen)
+{
+ ExaScreenPriv (pScreen);
+
+ ExaOffscreenValidate (pScreen);
+ /* loop until a single free area spans the space */
+ for (;;)
+ {
+ ExaOffscreenArea *area;
+
+ for (area = pExaScr->info->offScreenAreas; area != NULL;
+ area = area->next)
+ {
+ if (area->state == ExaOffscreenRemovable &&
+ area->save == exaPixmapSave)
+ {
+ (void) ExaOffscreenKickOut (pScreen, area);
+ ExaOffscreenValidate (pScreen);
+ break;
+ }
+ }
+ if (area == NULL)
+ break;
+ }
+ ExaOffscreenValidate (pScreen);
+}
+
+void
+ExaOffscreenSwapIn (ScreenPtr pScreen)
+{
+ exaOffscreenInit (pScreen);
+}
+
+/**
+ * Prepares EXA for disabling of FB access, or restoring it.
+ *
+ * In version 2.1, the disabling results in pixmaps being ejected, while other
+ * allocations remain. With this plus the prevention of migration while
+ * swappedOut is set, EXA by itself should not cause any access of the
+ * framebuffer to occur while swapped out. Any remaining issues are the
+ * responsibility of the driver.
+ *
+ * Prior to version 2.1, all allocations, including locked ones, are ejected
+ * when access is disabled, and the allocator is torn down while swappedOut
+ * is set. This is more drastic, and caused implementation difficulties for
+ * many drivers that could otherwise handle the lack of FB access while
+ * swapped out.
+ */
+void
+exaEnableDisableFBAccess (int index, Bool enable)
+{
+ ScreenPtr pScreen = screenInfo.screens[index];
+ ExaScreenPriv (pScreen);
+
+ if (!enable && pExaScr->disableFbCount++ == 0) {
+ if (pExaScr->info->exa_minor < 1)
+ ExaOffscreenSwapOut (pScreen);
+ else
+ ExaOffscreenEjectPixmaps (pScreen);
+ pExaScr->swappedOut = TRUE;
+ }
+
+ if (enable && --pExaScr->disableFbCount == 0) {
+ if (pExaScr->info->exa_minor < 1)
+ ExaOffscreenSwapIn (pScreen);
+ pExaScr->swappedOut = FALSE;
+ }
+}
+
+/* merge the next free area into this one */
+static void
+ExaOffscreenMerge (ExaOffscreenArea *area)
+{
+ ExaOffscreenArea *next = area->next;
+
+ /* account for space */
+ area->size += next->size;
+ /* frob pointer */
+ area->next = next->next;
+ xfree (next);
+}
+
+/**
+ * exaOffscreenFree frees an allocation.
+ *
+ * @param pScreen current screen
+ * @param area offscreen area to free
+ *
+ * exaOffscreenFree frees an allocation created by exaOffscreenAlloc. Note that
+ * the save callback of the area is not called, and it is up to the driver to
+ * do any cleanup necessary as a result.
+ *
+ * @return pointer to the newly freed area. This behavior should not be relied
+ * on.
+ */
+ExaOffscreenArea *
+exaOffscreenFree (ScreenPtr pScreen, ExaOffscreenArea *area)
+{
+ ExaScreenPriv(pScreen);
+ ExaOffscreenArea *next = area->next;
+ ExaOffscreenArea *prev;
+
+ DBG_OFFSCREEN (("Free 0x%x -> 0x%x (0x%x)\n", area->size,
+ area->base_offset, area->offset));
+ ExaOffscreenValidate (pScreen);
+
+ area->state = ExaOffscreenAvail;
+ area->save = NULL;
+ area->last_use = 0;
+ area->eviction_cost = 0;
+ /*
+ * Find previous area
+ */
+ if (area == pExaScr->info->offScreenAreas)
+ prev = NULL;
+ else
+ for (prev = pExaScr->info->offScreenAreas; prev; prev = prev->next)
+ if (prev->next == area)
+ break;
+
+ /* link with next area if free */
+ if (next && next->state == ExaOffscreenAvail)
+ ExaOffscreenMerge (area);
+
+ /* link with prev area if free */
+ if (prev && prev->state == ExaOffscreenAvail)
+ {
+ area = prev;
+ ExaOffscreenMerge (area);
+ }
+
+ ExaOffscreenValidate (pScreen);
+ DBG_OFFSCREEN(("\tdone freeing\n"));
+ return area;
+}
+
+void
+ExaOffscreenMarkUsed (PixmapPtr pPixmap)
+{
+ ExaPixmapPriv (pPixmap);
+ ExaScreenPriv (pPixmap->drawable.pScreen);
+
+ if (!pExaPixmap || !pExaPixmap->area)
+ return;
+
+ pExaPixmap->area->last_use = pExaScr->offScreenCounter++;
+}
+
+/**
+ * exaOffscreenInit initializes the offscreen memory manager.
+ *
+ * @param pScreen current screen
+ *
+ * exaOffscreenInit is called by exaDriverInit to set up the memory manager for
+ * the screen, if any offscreen memory is available.
+ */
+Bool
+exaOffscreenInit (ScreenPtr pScreen)
+{
+ ExaScreenPriv (pScreen);
+ ExaOffscreenArea *area;
+
+ /* Allocate a big free area */
+ area = xalloc (sizeof (ExaOffscreenArea));
+
+ if (!area)
+ return FALSE;
+
+ area->state = ExaOffscreenAvail;
+ area->base_offset = pExaScr->info->offScreenBase;
+ area->offset = area->base_offset;
+ area->size = pExaScr->info->memorySize - area->base_offset;
+ area->save = NULL;
+ area->next = NULL;
+ area->last_use = 0;
+ area->eviction_cost = 0;
+
+ /* Add it to the free areas */
+ pExaScr->info->offScreenAreas = area;
+ pExaScr->offScreenCounter = 1;
+
+ ExaOffscreenValidate (pScreen);
+
+ return TRUE;
+}
+
+void
+ExaOffscreenFini (ScreenPtr pScreen)
+{
+ ExaScreenPriv (pScreen);
+ ExaOffscreenArea *area;
+
+ /* just free all of the area records */
+ while ((area = pExaScr->info->offScreenAreas))
+ {
+ pExaScr->info->offScreenAreas = area->next;
+ xfree (area);
+ }
+}