vfs: check userland buffers before reading them.

[haiku.git] / src / add-ons / accelerants / neomagic / Overlay.c

/* Written by Rudolf Cornelissen 05-2002/4-2006 */

/* Note on 'missing features' in BeOS 5.0.3 and DANO:
 * BeOS needs to define more colorspaces! It would be nice if BeOS would support the FourCC 'definitions'
 * of colorspaces. These colorspaces are 32bit words, so it could be simply done (or is it already so?)
 */

#define MODULE_BIT 0x00000400

#include "acc_std.h"

/* define the supported overlay input colorspaces */
static uint32 overlay_colorspaces [] = { (uint32)B_YCbCr422, (uint32)B_NO_COLOR_SPACE };

uint32 OVERLAY_COUNT(const display_mode *dm) 
// This method is never used AFAIK though it *is* exported on R5.0.3 and DANO.
// Does someone know howto invoke it?
{
        LOG(4,("Overlay: count called\n"));

        /* check for NULL pointer */
        if (dm == NULL)
        {
                LOG(4,("Overlay: No display mode specified!\n"));
        }
        /* apparantly overlay count should report the number of 'overlay units' on the card */
        return 1;
}

const uint32 *OVERLAY_SUPPORTED_SPACES(const display_mode *dm)
// This method is never used AFAIK though it *is* exported on R5.0.3 and DANO.
// Does someone know howto invoke it?
{
        LOG(4,("Overlay: supported_spaces called.\n"));

        /* check for NULL pointer */
        if (dm == NULL)
        {
                LOG(4,("Overlay: No display mode specified!\n"));
                return NULL;
        }

        /* assuming interlaced VGA is not supported */
        if (dm->timing.flags & B_TIMING_INTERLACED)
        {
                return NULL;
        }
        /* return a B_NO_COLOR_SPACE terminated list */
        return &overlay_colorspaces[0];
}

uint32 OVERLAY_SUPPORTED_FEATURES(uint32 a_color_space)
// This method is never used AFAIK. On R5.0.3 and DANO it is not even exported!
{
        LOG(4,("Overlay: supported_features: color_space $%08x\n",a_color_space));

        /* check what features are supported for the current overlaybitmap colorspace */
        switch (a_color_space)
        {
        default:
                        return 
                                ( B_OVERLAY_COLOR_KEY                    |
                                  B_OVERLAY_HORIZONTAL_FILTERING |
                                  B_OVERLAY_VERTICAL_FILTERING );
        }
}

const overlay_buffer *ALLOCATE_OVERLAY_BUFFER(color_space cs, uint16 width, uint16 height)
{
        int offset = 0;                                 /* used to determine next buffer to create */
        uint32 adress, adress2, temp32; /* used to calculate buffer adresses */
        uint32 oldsize = 0;                             /* used to 'squeeze' new buffers between already existing ones */
        int cnt;                                                /* loopcounter */

        /* acquire the shared benaphore */
        AQUIRE_BEN(si->overlay.lock)

        LOG(4,("Overlay: cardRAM_start = $%08x\n",(uint32)((uint8*)si->framebuffer)));
        LOG(4,("Overlay: cardRAM_start_DMA = $%08x\n",(uint32)((uint8*)si->framebuffer_pci)));
        LOG(4,("Overlay: cardRAM_size = %dKb\n",si->ps.memory_size));

        /* find first empty slot (room for another buffer?) */
        for (offset = 0; offset < MAXBUFFERS; offset++)
        {
                if (si->overlay.myBuffer[offset].buffer == NULL) break;
        }

        LOG(4,("Overlay: Allocate_buffer offset = %d\n",offset));

        if (offset < MAXBUFFERS)
        /* setup new scaler input buffer */
        {
                switch (cs)
                {
                        case B_YCbCr422:
                                        /* check if slopspace is needed: NeoMagic cards can do with ~x0007 */
                                        if (width == (width & ~0x0007))
                                        {
                                                si->overlay.myBuffer[offset].width = width;
                                        }
                                        else
                                        {
                                                si->overlay.myBuffer[offset].width = (width & ~0x0007) + 8;
                                        }
                                        si->overlay.myBuffer[offset].bytes_per_row = 2 * si->overlay.myBuffer[offset].width;

                                        /* check if the requested horizontal pitch is supported */
                                        //fixme?...
                                        if (si->overlay.myBuffer[offset].width > 2048)
                                        {
                                                LOG(4,("Overlay: Sorry, requested buffer pitch not supported, aborted\n"));

                                                /* release the shared benaphore */
                                                RELEASE_BEN(si->overlay.lock)

                                                return NULL;
                                        }
                                        break;
                        default:
                                        /* unsupported colorspace! */
                                        LOG(4,("Overlay: Sorry, colorspace $%08x not supported, aborted\n",cs));

                                        /* release the shared benaphore */
                                        RELEASE_BEN(si->overlay.lock)

                                        return NULL;
                                        break;
                }

                /* check if the requested buffer width is supported */
                if (si->overlay.myBuffer[offset].width > 1024)
                {
                        LOG(4,("Overlay: Sorry, requested buffer width not supported, aborted\n"));

                        /* release the shared benaphore */
                        RELEASE_BEN(si->overlay.lock)

                        return NULL;
                }
                /* check if the requested buffer height is supported */
                if (height > 1024)
                {
                        LOG(4,("Overlay: Sorry, requested buffer height not supported, aborted\n"));

                        /* release the shared benaphore */
                        RELEASE_BEN(si->overlay.lock)

                        return NULL;
                }

                /* store slopspace (in pixels) for each bitmap for use by 'overlay unit' (BES) */
                si->overlay.myBufInfo[offset].slopspace = si->overlay.myBuffer[offset].width - width;

                si->overlay.myBuffer[offset].space = cs;
                si->overlay.myBuffer[offset].height = height;
        
                /* we define the overlay buffers to reside 'in the back' of the cards RAM */
                /* NOTE to app programmers:
                 * Beware that an app using overlay needs to track workspace switches and screenprefs
                 * changes. If such an action is detected, the app needs to reset it's pointers to the 
                 * newly created overlay bitmaps, which will be assigned by BeOS automatically after such
                 * an event. (Also the app needs to respect the new overlay_constraints that will be applicable!)
                 *
                 * It is entirely possible that new bitmaps may *not* be re-setup at all, or less of them
                 * than previously setup by the app might be re-setup. This is due to cardRAM restraints then.
                 * This means that the app should also check for NULL pointers returned by the bitmaps,
                 * and if this happens, it needs to fallback to single buffered overlay or even fallback to
                 * bitmap output for the new situation. */

                /* Another NOTE for app programmers:
                 * A *positive* side-effect of assigning the first overlay buffer exactly at the end of the
                 * cardRAM is that apps that try to write beyond the buffer's space get a segfault immediately.
                 * This *greatly* simplifies tracking such errors! 
                 * Of course such errors may lead to strange effects in the app or driver behaviour if they are
                 * not hunted down and removed.. */

                /* calculate first free RAM adress in card:
                 * Driver setup is as follows: 
                 * card base:           - screen memory,
                 * free space:      - used for overlay,
                 * card top:        - hardware cursor bitmap (if used) */
                adress2 = (((uint32)((uint8*)si->fbc.frame_buffer)) +   /* cursor not yet included here */
                        (si->fbc.bytes_per_row * si->dm.virtual_height));       /* size in bytes of screen(s) */
                LOG(4,("Overlay: first free cardRAM virtual adress $%08x\n", adress2));

                /* calculate 'preliminary' buffer size including slopspace */
                oldsize = si->overlay.myBufInfo[offset].size;
                si->overlay.myBufInfo[offset].size = 
                        si->overlay.myBuffer[offset].bytes_per_row * si->overlay.myBuffer[offset].height;

                /* calculate virtual memory adress that would be needed for a new bitmap */
                adress = (((uint32)((uint8*)si->framebuffer)) + (si->ps.memory_size * 1024));
                /* take cursor into account (if it exists) */
                if(si->settings.hardcursor) adress -= si->ps.curmem_size;
                LOG(4,("Overlay: last free cardRAM virtual adress $%08x\n", (adress - 1)));
                for (cnt = 0; cnt <= offset; cnt++)
                {
                        adress -= si->overlay.myBufInfo[cnt].size;
                }

                /* the > G200 scalers require buffers to be aligned to 16 byte pages cardRAM offset, G200 can do with
                 * 8 byte pages cardRAM offset. Compatible settings used, has no real downside consequences here */

                /* Check if we need to modify the buffers starting adress and thus the size */
                /* calculate 'would be' cardRAM offset */
                temp32 = (adress - ((uint32)((vuint32 *)si->framebuffer)));
                /* check if it is aligned */
                if (temp32 != (temp32 & 0xfffffff0))
                {
                        /* update the (already calculated) buffersize to get it aligned */
                        si->overlay.myBufInfo[offset].size += (temp32 - (temp32 & 0xfffffff0));
                        /* update the (already calculated) adress to get it aligned */
                        adress -= (temp32 - (temp32 & 0xfffffff0));
                }
                LOG(4,("Overlay: new buffer needs virtual adress $%08x\n", adress));

                /* First check now if buffer to be defined is 'last one' in memory (speaking backwards):
                 * this is done to prevent a large buffer getting created in the space a small buffer 
                 * occupied earlier, if not all buffers created were deleted.
                 * Note also that the app can delete the buffers in any order desired. */

                /* NOTE to app programmers: 
                 * If you are going to delete a overlay buffer you created, you should delete them *all* and
                 * then re-create only the new ones needed. This way you are sure not to get unused memory-
                 * space in between your overlay buffers for instance, so cardRAM is used 'to the max'. 
                 * If you don't, you might not get a buffer at all if you are trying to set up a larger one
                 * than before. 
                 * (Indeed: not all buffers *have* to be of the same type and size...) */

                for (cnt = offset; cnt < MAXBUFFERS; cnt++)
                {
                        if (si->overlay.myBuffer[cnt].buffer != NULL)
                        {
                                /* Check if the new buffer would fit into the space the single old one used here */
                                if (si->overlay.myBufInfo[offset].size <= oldsize)
                                {
                                        /* It does, so we reset to the old size and adresses to prevent the space from shrinking
                                         * if we get here again... */
                                        adress -= (oldsize - si->overlay.myBufInfo[offset].size);
                                        si->overlay.myBufInfo[offset].size = oldsize;
                                        LOG(4,("Overlay: 'squeezing' in buffer:\n"
                                                   "Overlay: resetting it to virtual adress $%08x and size $%08x\n", adress,oldsize));
                                        /* force exiting the FOR loop */
                                        cnt = MAXBUFFERS;
                                }
                                else
                                {
                                        /* nogo, sorry */
                                        LOG(4,("Overlay: Other buffer(s) exist after this one:\n"
                                                   "Overlay: not enough space to 'squeeze' this one in, aborted\n"));

                                        /* Reset to the old size to prevent the space from 'growing' if we get here again... */
                                        si->overlay.myBufInfo[offset].size = oldsize;

                                        /* release the shared benaphore */
                                        RELEASE_BEN(si->overlay.lock)

                                        return NULL;
                                }
                        }
                }

                /* check if we have enough space to setup this new bitmap 
                 * (preventing overlap of desktop RAMspace & overlay bitmap RAMspace here) */
                if (adress < adress2)
                /* nope, sorry */
                {
                        LOG(4,("Overlay: Sorry, no more space for buffers: aborted\n"));

                        /* release the shared benaphore */
                        RELEASE_BEN(si->overlay.lock)

                        return NULL;
                }
                /* continue buffer setup */             
                si->overlay.myBuffer[offset].buffer = (void *) adress;

                /* calculate physical memory adress (for dma use) */
                adress = (((uint32)((uint8*)si->framebuffer_pci)) + (si->ps.memory_size * 1024));
                /* take cursor into account (if it exists) */
                if(si->settings.hardcursor) adress -= si->ps.curmem_size;
                for (cnt = 0; cnt <= offset; cnt++)
                {
                        adress -= si->overlay.myBufInfo[cnt].size;
                }
                /* this adress is already aligned to the scaler's requirements (via the already modified sizes) */
                si->overlay.myBuffer[offset].buffer_dma = (void *) adress;

                LOG(4,("Overlay: New buffer: addr $%08x, dma_addr $%08x, color space $%08x\n",
                        (uint32)((uint8*)si->overlay.myBuffer[offset].buffer),
                        (uint32)((uint8*)si->overlay.myBuffer[offset].buffer_dma), cs));
                LOG(4,("Overlay: New buffer's size is $%08x\n", si->overlay.myBufInfo[offset].size));
                        
                /* release the shared benaphore */
                RELEASE_BEN(si->overlay.lock)

                return &si->overlay.myBuffer[offset];
        }
        else
        /* sorry, no more room for buffers */
        {       
                LOG(4,("Overlay: Sorry, no more space for buffers: aborted\n"));

                /* release the shared benaphore */
                RELEASE_BEN(si->overlay.lock)

                return NULL;
        }
}

status_t RELEASE_OVERLAY_BUFFER(const overlay_buffer *ob)
/* Note that the user can delete the buffers in any order desired! */
{
        int offset = 0;

        if (ob != NULL)
        {
                /* find the buffer */
                for (offset = 0; offset < MAXBUFFERS; offset++)
                {
                        if (si->overlay.myBuffer[offset].buffer == ob->buffer) break;
                }

                if (offset < MAXBUFFERS)
                /* delete current buffer */
                {
                        si->overlay.myBuffer[offset].buffer = NULL;             
                        si->overlay.myBuffer[offset].buffer_dma = NULL;         
                        
                        LOG(4,("Overlay: Release_buffer offset = %d, buffer released\n",offset));

                        return B_OK;
                }
                else
                {
                        /* this is no buffer of ours! */
                        LOG(4,("Overlay: Release_overlay_buffer: not ours, aborted!\n"));

                        return B_ERROR;
                }
        }
        else
        /* no buffer specified! */
        {
                LOG(4,("Overlay: Release_overlay_buffer: no buffer specified, aborted!\n"));

                return B_ERROR;
        }       
}

status_t GET_OVERLAY_CONSTRAINTS
        (const display_mode *dm, const overlay_buffer *ob, overlay_constraints *oc)
{
        int offset = 0;

        LOG(4,("Overlay: Get_overlay_constraints called\n"));

        /* check for NULL pointers */
        if ((dm == NULL) || (ob == NULL) || (oc == NULL))
        {
                LOG(4,("Overlay: Get_overlay_constraints: Null pointer(s) detected!\n"));
                return B_ERROR;
        }
        
        /* find the buffer */
        for (offset = 0; offset < MAXBUFFERS; offset++)
        {
                if (si->overlay.myBuffer[offset].buffer == ob->buffer) break;
        }

        if (offset < MAXBUFFERS)
        {
                /* scaler input (values are in pixels) */
                oc->view.h_alignment = 0;
                oc->view.v_alignment = 0;

                switch (ob->space)
                {
                        case B_YCbCr422:
                                        /* NeoMagic cards can work with 7. 
                                         * Note: this has to be in sync with the slopspace setup during buffer allocation.. */
                                        //fixme: >= NM2200 use 16 instead of 8???
                                        oc->view.width_alignment = 7;
                                        break;
                        default:
                                        /* we should not be here, but set the worst-case value just to be safe anyway */
                                        oc->view.width_alignment = 31;
                                        break;
                }

                oc->view.height_alignment = 0;
                oc->view.width.min = 1;
                oc->view.height.min = 2; /* two fields */
                oc->view.width.max = ob->width;
                oc->view.height.max = ob->height;

                /* scaler output restrictions */
                oc->window.h_alignment = 0;
                oc->window.v_alignment = 0;
                oc->window.width_alignment = 0;
                oc->window.height_alignment = 0;
                oc->window.width.min = 2;
                /* G200-G550 can output upto and including 2048 pixels in width */
                //fixme...
                if (dm->virtual_width > 2048)
                {
                        oc->window.width.max = 2048;
                }
                else
                {
                        oc->window.width.max = dm->virtual_width;
                }
                oc->window.height.min = 2;
                /* G200-G550 can output upto and including 2048 pixels in height */
                //fixme...
                if (dm->virtual_height > 2048)
                {
                        oc->window.height.max = 2048;
                }
                else
                {
                        oc->window.height.max = dm->virtual_height;
                }

                /* NeoMagic scaling restrictions */
                /* Note: official max is 8.0, and NM BES does not support downscaling! */
                oc->h_scale.min = 1.0;
                oc->h_scale.max = 8.0;
                oc->v_scale.min = 1.0;
                oc->v_scale.max = 8.0;

                return B_OK;
        }
        else
        {
                /* this is no buffer of ours! */
                LOG(4,("Overlay: Get_overlay_constraints: buffer is not ours, aborted!\n"));

                return B_ERROR;
        }
}

overlay_token ALLOCATE_OVERLAY(void)
{
        uint32 tmpToken;
        LOG(4,("Overlay: Allocate_overlay called: "));

        /* come up with a token */
        tmpToken = 0x12345678;

        /* acquire the shared benaphore */
        AQUIRE_BEN(si->overlay.lock)

        /* overlay unit already in use? */
        if (si->overlay.myToken == NULL)
        /* overlay unit is available */
        {
                LOG(4,("succesfull\n"));

                si->overlay.myToken = &tmpToken;

                /* release the shared benaphore */
                RELEASE_BEN(si->overlay.lock)

                return si->overlay.myToken;
        }
        else
        /* sorry, overlay unit is occupied */
        {
                LOG(4,("failed: already in use!\n"));

                /* release the shared benaphore */
                RELEASE_BEN(si->overlay.lock)

                return NULL;
        }
}

status_t RELEASE_OVERLAY(overlay_token ot)
{
        LOG(4,("Overlay: Release_overlay called: "));

        /* is this call for real? */
        if ((ot == NULL) || (si->overlay.myToken == NULL) || (ot != si->overlay.myToken))
        /* nope, abort */
        {
                LOG(4,("failed, not in use!\n"));

                return B_ERROR;
        }
        else
        /* call is for real */
        {

                nm_release_bes();

                LOG(4,("succesfull\n"));

                si->overlay.myToken = NULL;
                return B_OK;
        }
}

status_t CONFIGURE_OVERLAY
        (overlay_token ot, const overlay_buffer *ob, const overlay_window *ow, const overlay_view *ov)
{
        int offset = 0; /* used for buffer index */

        LOG(4,("Overlay: Configure_overlay called: "));

        /* Note:
         * When a Workspace switch, screen prefs change, or overlay app shutdown occurs, BeOS will
         * release all overlay buffers. The buffer currently displayed at that moment, may need some
         * 'hardware releasing' in the CONFIGURE_OVERLAY routine. This is why CONFIGURE_OVERLAY gets
         * called one more time then, with a null pointer for overlay_window and overlay_view, while
         * the currently displayed overlay_buffer is given.
         * The G200-G550 do not need to do anything on such an occasion, so we simply return if we
         * get called then. */
        if ((ow == NULL) || (ov == NULL))
        {
                LOG(4,("output properties changed\n"));

                return B_OK;
        }       

        /* Note:
         * If during overlay use the screen prefs are changed, or the workspace has changed, it
         * may be that we were not able to re-allocate the requested overlay buffers (or only partly)
         * due to lack of cardRAM. If the app does not respond properly to this, we might end up 
         * with a NULL pointer instead of a overlay_buffer to work with here. 
         * Of course, we need to abort then to prevent the system from 'going down'.
         * The app will probably crash because it will want to write into this non-existant buffer
         * at some point. */
        if (ob == NULL)
        {
                LOG(4,("no overlay buffer specified\n"));

                return B_ERROR;
        }       

        /* is this call done by the app that owns us? */
        if ((ot == NULL) || (si->overlay.myToken == NULL) || (ot != si->overlay.myToken))
        /* nope, abort */
        {
                LOG(4,("failed\n"));

                return B_ERROR;
        }
        else
        /* call is for real */
        {
                /* find the buffer's offset */
                for (offset = 0; offset < MAXBUFFERS; offset++)
                {
                        if (si->overlay.myBuffer[offset].buffer == ob->buffer) break;
                }

                if (offset < MAXBUFFERS)
                {
                        LOG(4,("succesfull, switching to buffer %d\n", offset));

                        nm_configure_bes(ob, ow, ov, offset);

                        return B_OK;
                }
                else
                {
                        /* this is no buffer of ours! */
                        LOG(4,("buffer is not ours, aborted!\n"));

                        return B_ERROR;
                }
        }
}