From a396617dbc15abafdc172b972a02c04007ad579f Mon Sep 17 00:00:00 2001 From: Felix Kuehling Date: Sun, 13 Mar 2005 02:16:10 +0000 Subject: Command DMA optimizations: - don't waste DMA memory when small command buffers are flushed - minimized padding with noops - slightly simplified faked DMA flushing --- shared-core/savage_bci.c | 70 +++++++++++++++++++++++++++++++----------------- 1 file changed, 46 insertions(+), 24 deletions(-) (limited to 'shared-core/savage_bci.c') diff --git a/shared-core/savage_bci.c b/shared-core/savage_bci.c index 3bf865dd..ce7139ad 100644 --- a/shared-core/savage_bci.c +++ b/shared-core/savage_bci.c @@ -305,6 +305,7 @@ static int savage_dma_init(drm_savage_private_t *dev_priv) for (i = 0; i < dev_priv->nr_dma_pages; ++i) { SET_AGE(&dev_priv->dma_pages[i].age, 0, 0); dev_priv->dma_pages[i].used = 0; + dev_priv->dma_pages[i].flushed = 0; } SET_AGE(&dev_priv->last_dma_age, 0, 0); @@ -323,6 +324,7 @@ void savage_dma_reset(drm_savage_private_t *dev_priv) for (i = 0; i < dev_priv->nr_dma_pages; ++i) { SET_AGE(&dev_priv->dma_pages[i].age, event, wrap); dev_priv->dma_pages[i].used = 0; + dev_priv->dma_pages[i].flushed = 0; } SET_AGE(&dev_priv->last_dma_age, event, wrap); dev_priv->first_dma_page = dev_priv->current_dma_page = 0; @@ -384,6 +386,7 @@ uint32_t *savage_dma_alloc(drm_savage_private_t *dev_priv, unsigned int n) for (i = cur; i < dev_priv->nr_dma_pages; ++i) { dev_priv->dma_pages[i].age = dev_priv->last_dma_age; dev_priv->dma_pages[i].used = 0; + dev_priv->dma_pages[i].flushed = 0; } dma_ptr = (uint32_t *)dev_priv->cmd_dma->handle; dev_priv->first_dma_page = cur = 0; @@ -414,21 +417,27 @@ uint32_t *savage_dma_alloc(drm_savage_private_t *dev_priv, unsigned int n) static void savage_dma_flush(drm_savage_private_t *dev_priv) { BCI_LOCALS; + unsigned int first = dev_priv->first_dma_page; unsigned int cur = dev_priv->current_dma_page; uint16_t event; - unsigned int wrap, pad, len, i; + unsigned int wrap, pad, align, len, i; unsigned long phys_addr; - if (dev_priv->first_dma_page == dev_priv->current_dma_page && - dev_priv->dma_pages[dev_priv->current_dma_page].used == 0) + if (first == cur && + dev_priv->dma_pages[cur].used == dev_priv->dma_pages[cur].flushed) return; - /* pad to multiples of 8 entries (really needed? 2 should do it) */ - pad = -dev_priv->dma_pages[cur].used & 7; - DRM_DEBUG("first=%u, cur=%u, cur->used=%u, pad=%u\n", - dev_priv->first_dma_page, cur, dev_priv->dma_pages[cur].used, - pad); + /* pad length to multiples of 2 entries + * align start of next DMA block to multiles of 8 entries */ + pad = -dev_priv->dma_pages[cur].used & 1; + align = -(dev_priv->dma_pages[cur].used + pad) & 7; + + DRM_DEBUG("first=%u, cur=%u, first->flushed=%u, cur->used=%u, " + "pad=%u, align=%u\n", + first, cur, dev_priv->dma_pages[first].flushed, + dev_priv->dma_pages[cur].used, pad, align); + /* pad with noops */ if (pad) { uint32_t *dma_ptr = (uint32_t *)dev_priv->cmd_dma->handle + cur * SAVAGE_DMA_PAGE_SIZE + @@ -444,9 +453,11 @@ static void savage_dma_flush(drm_savage_private_t *dev_priv) /* do flush ... */ phys_addr = dev_priv->cmd_dma->offset + - dev_priv->first_dma_page * SAVAGE_DMA_PAGE_SIZE*4; - len = (cur - dev_priv->first_dma_page) * SAVAGE_DMA_PAGE_SIZE + - dev_priv->dma_pages[cur].used; + (first * SAVAGE_DMA_PAGE_SIZE + + dev_priv->dma_pages[first].flushed) * 4; + len = (cur - first) * SAVAGE_DMA_PAGE_SIZE + + dev_priv->dma_pages[cur].used - + dev_priv->dma_pages[first].flushed; DRM_DEBUG("phys_addr=%lx, len=%u\n", phys_addr | dev_priv->dma_type, len); @@ -456,23 +467,36 @@ static void savage_dma_flush(drm_savage_private_t *dev_priv) BCI_WRITE(phys_addr | dev_priv->dma_type); BCI_DMA(len); + /* fix alignment of the start of the next block */ + dev_priv->dma_pages[cur].used += align; + /* age DMA pages */ event = savage_bci_emit_event(dev_priv, 0); wrap = dev_priv->event_wrap; - for (i = dev_priv->first_dma_page; - i <= dev_priv->current_dma_page; ++i) { + for (i = first; i < cur; ++i) { SET_AGE(&dev_priv->dma_pages[i].age, event, wrap); dev_priv->dma_pages[i].used = 0; + dev_priv->dma_pages[i].flushed = 0; + } + /* age the current page only when it's full */ + if (dev_priv->dma_pages[cur].used == SAVAGE_DMA_PAGE_SIZE) { + SET_AGE(&dev_priv->dma_pages[cur].age, event, wrap); + dev_priv->dma_pages[cur].used = 0; + dev_priv->dma_pages[cur].flushed = 0; + /* advance to next page */ + cur++; + if (cur == dev_priv->nr_dma_pages) + cur = 0; + dev_priv->first_dma_page = dev_priv->current_dma_page = cur; + } else { + dev_priv->first_dma_page = cur; + dev_priv->dma_pages[cur].flushed = dev_priv->dma_pages[i].used; } SET_AGE(&dev_priv->last_dma_age, event, wrap); - /* advance to next page */ - if (i == dev_priv->nr_dma_pages) - i = 0; - dev_priv->first_dma_page = dev_priv->current_dma_page = i; - - DRM_DEBUG("first=cur=%u, cur->used=%u\n", i, - dev_priv->dma_pages[i].used); + DRM_DEBUG("first=cur=%u, cur->used=%u, cur->flushed=%u\n", cur, + dev_priv->dma_pages[cur].used, + dev_priv->dma_pages[cur].flushed); } static void savage_fake_dma_flush(drm_savage_private_t *dev_priv) @@ -507,10 +531,8 @@ static void savage_fake_dma_flush(drm_savage_private_t *dev_priv) dev_priv->dma_pages[i].used = 0; } - /* advance to next page */ - if (i == dev_priv->nr_dma_pages) - i = 0; - dev_priv->first_dma_page = dev_priv->current_dma_page = i; + /* reset to first page */ + dev_priv->first_dma_page = dev_priv->current_dma_page = 0; } /* -- cgit v1.2.3