ARM: OMAP: FB sync with N800 tree (support for dynamic SRAM allocations)

- in addition to fixed FB regions - as passed by the bootloader -
  allow dynamic allocations
- do some more checking against overlapping / reserved regions
- move the FB specific parts out from sram.c to fb.c

Signed-off-by: Imre Deak <imre.deak@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 247 insertions, 30 deletions

diff --git a/arch/arm/plat-omap/fb.c b/arch/arm/plat-omap/fb.c
index a302d9194f5..469f580ca05 100644
--- a/arch/arm/plat-omap/fb.c
+++ b/arch/arm/plat-omap/fb.c
@@ -39,6 +39,8 @@
 #if defined(CONFIG_FB_OMAP) || defined(CONFIG_FB_OMAP_MODULE)
 
 static struct omapfb_platform_data omapfb_config;
+static int config_invalid;
+static int configured_regions;
 
 static u64 omap_fb_dma_mask = ~(u32)0;
 
@@ -53,46 +55,246 @@ static struct platform_device omap_fb_device = {
 	.num_resources = 0,
 };
 
-/* called from map_io */
-void omapfb_reserve_mem(void)
+static inline int ranges_overlap(unsigned long start1, unsigned long size1,
+				 unsigned long start2, unsigned long size2)
 {
-	const struct omap_fbmem_config *fbmem_conf;
-	unsigned long total_size;
+	return (start1 >= start2 && start1 < start2 + size2) ||
+	       (start2 >= start1 && start2 < start1 + size1);
+}
+
+static inline int range_included(unsigned long start1, unsigned long size1,
+				 unsigned long start2, unsigned long size2)
+{
+	return start1 >= start2 && start1 + size1 <= start2 + size2;
+}
+
+
+/* Check if there is an overlapping region. */
+static int fbmem_region_reserved(unsigned long start, size_t size)
+{
+	struct omapfb_mem_region *rg;
 	int i;
 
-	if (!omap_fb_sram_valid) {
-		/* FBMEM SRAM configuration was already found to be invalid.
-		 * Ignore the whole configuration block. */
-		omapfb_config.mem_desc.region_cnt = 0;
-		return;
+	rg = &omapfb_config.mem_desc.region[0];
+	for (i = 0; i < OMAPFB_PLANE_NUM; i++, rg++) {
+		if (!rg->paddr)
+			/* Empty slot. */
+			continue;
+		if (ranges_overlap(start, size, rg->paddr, rg->size))
+			return 1;
 	}
+	return 0;
+}
 
-	i = 0;
-	total_size = 0;
-	while ((fbmem_conf = omap_get_nr_config(OMAP_TAG_FBMEM,
-				struct omap_fbmem_config, i)) != NULL) {
-		unsigned long start;
-		unsigned long size;
+/*
+ * Get the region_idx`th region from board config/ATAG and convert it to
+ * our internal format.
+ */
+static int get_fbmem_region(int region_idx, struct omapfb_mem_region *rg)
+{
+	const struct omap_fbmem_config	*conf;
+	u32				paddr;
 
-		if (i == OMAPFB_PLANE_NUM) {
-			printk(KERN_ERR "ignoring extra plane info\n");
+	conf = omap_get_nr_config(OMAP_TAG_FBMEM,
+				  struct omap_fbmem_config, region_idx);
+	if (conf == NULL)
+		return -ENOENT;
+
+	paddr = conf->start;
+	/*
+	 * Low bits encode the page allocation mode, if high bits
+	 * are zero. Otherwise we need a page aligned fixed
+	 * address.
+	 */
+	memset(rg, 0, sizeof(*rg));
+	rg->type = paddr & ~PAGE_MASK;
+	rg->paddr = paddr & PAGE_MASK;
+	rg->size = PAGE_ALIGN(conf->size);
+	return 0;
+}
+
+static int set_fbmem_region_type(struct omapfb_mem_region *rg, int mem_type,
+				  unsigned long mem_start,
+				  unsigned long mem_size)
+{
+	/*
+	 * Check if the configuration specifies the type explicitly.
+	 * type = 0 && paddr = 0, a default don't care case maps to
+	 * the SDRAM type.
+	 */
+	if (rg->type || (!rg->type && !rg->paddr))
+		return 0;
+	if (ranges_overlap(rg->paddr, rg->size, mem_start, mem_size)) {
+		rg->type = mem_type;
+		return 0;
+	}
+	/* Can't determine it. */
+	return -1;
+}
+
+static int check_fbmem_region(int region_idx, struct omapfb_mem_region *rg,
+			      unsigned long start_avail, unsigned size_avail)
+{
+	unsigned long	paddr = rg->paddr;
+	size_t		size = rg->size;
+
+	if (rg->type > OMAPFB_MEMTYPE_MAX) {
+		printk(KERN_ERR
+			"Invalid start address for FB region %d\n", region_idx);
+		return -EINVAL;
+	}
+
+	if (!rg->size) {
+		printk(KERN_ERR "Zero size for FB region %d\n", region_idx);
+		return -EINVAL;
+	}
+
+	if (!paddr)
+		/* Allocate this dynamically, leave paddr 0 for now. */
+		return 0;
+
+	/*
+	 * Fixed region for the given RAM range. Check if it's already
+	 * reserved by the FB code or someone else.
+	 */
+	if (fbmem_region_reserved(paddr, size) ||
+	    !range_included(paddr, size, start_avail, size_avail)) {
+		printk(KERN_ERR "Trying to use reserved memory "
+			"for FB region %d\n", region_idx);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Called from map_io. We need to call to this early enough so that we
+ * can reserve the fixed SDRAM regions before VM could get hold of them.
+ */
+void omapfb_reserve_sdram(void)
+{
+	struct bootmem_data	*bdata;
+	unsigned long		sdram_start, sdram_size;
+	unsigned long		reserved;
+	int			i;
+
+	if (config_invalid)
+		return;
+
+	bdata = NODE_DATA(0)->bdata;
+	sdram_start = bdata->node_boot_start;
+	sdram_size = (bdata->node_low_pfn << PAGE_SHIFT) - sdram_start;
+	reserved = 0;
+	for (i = 0; ; i++) {
+		struct omapfb_mem_region	rg;
+
+		if (get_fbmem_region(i, &rg) < 0)
 			break;
+		if (i == OMAPFB_PLANE_NUM) {
+			printk(KERN_ERR
+				"Extraneous FB mem configuration entries\n");
+			config_invalid = 1;
+			return;
 		}
-		start = fbmem_conf->start;
-		size  = fbmem_conf->size;
-		omapfb_config.mem_desc.region[i].paddr = start;
-		omapfb_config.mem_desc.region[i].size = size;
-		if (omap_fb_sram_plane != i && start) {
-			reserve_bootmem(start, size);
-			total_size += size;
+		/* Check if it's our memory type. */
+		if (set_fbmem_region_type(&rg, OMAPFB_MEMTYPE_SDRAM,
+				          sdram_start, sdram_size) < 0 ||
+		    (rg.type != OMAPFB_MEMTYPE_SDRAM))
+			continue;
+		BUG_ON(omapfb_config.mem_desc.region[i].size);
+		if (check_fbmem_region(i, &rg, sdram_start, sdram_size) < 0) {
+			config_invalid = 1;
+			return;
 		}
-		i++;
+		if (rg.paddr)
+			reserve_bootmem(rg.paddr, rg.size);
+		reserved += rg.size;
+		omapfb_config.mem_desc.region[i] = rg;
+		configured_regions++;
 	}
 	omapfb_config.mem_desc.region_cnt = i;
-	if (total_size)
+	if (reserved)
 		pr_info("Reserving %lu bytes SDRAM for frame buffer\n",
-			 total_size);
+			 reserved);
+}
+
+/*
+ * Called at sram init time, before anything is pushed to the SRAM stack.
+ * Because of the stack scheme, we will allocate everything from the
+ * start of the lowest address region to the end of SRAM. This will also
+ * include padding for page alignment and possible holes between regions.
+ *
+ * As opposed to the SDRAM case, we'll also do any dynamic allocations at
+ * this point, since the driver built as a module would have problem with
+ * freeing / reallocating the regions.
+ */
+unsigned long omapfb_reserve_sram(unsigned long sram_pstart,
+				  unsigned long sram_vstart,
+				  unsigned long sram_size,
+				  unsigned long pstart_avail,
+				  unsigned long size_avail)
+{
+	struct omapfb_mem_region	rg;
+	unsigned long			pend_avail;
+	unsigned long			reserved;
+	int				i;
+
+	if (config_invalid)
+		return 0;
+
+	reserved = 0;
+	pend_avail = pstart_avail + size_avail;
+	for (i = 0; ; i++) {
+		if (get_fbmem_region(i, &rg) < 0)
+			break;
+		if (i == OMAPFB_PLANE_NUM) {
+			printk(KERN_ERR
+				"Extraneous FB mem configuration entries\n");
+			config_invalid = 1;
+			return 0;
+		}
 
+		/* Check if it's our memory type. */
+		if (set_fbmem_region_type(&rg, OMAPFB_MEMTYPE_SRAM,
+				          sram_pstart, sram_size) < 0 ||
+		    (rg.type != OMAPFB_MEMTYPE_SRAM))
+			continue;
+		BUG_ON(omapfb_config.mem_desc.region[i].size);
+
+		if (check_fbmem_region(i, &rg, pstart_avail, size_avail) < 0) {
+			config_invalid = 1;
+			return 0;
+		}
+
+		if (!rg.paddr) {
+			/* Dynamic allocation */
+			if ((size_avail & PAGE_MASK) < rg.size) {
+				printk("Not enough SRAM for FB region %d\n",
+					i);
+				config_invalid = 1;
+				return 0;
+			}
+			size_avail = (size_avail - rg.size) & PAGE_MASK;
+			rg.paddr = pstart_avail + size_avail;
+		}
+		/* Reserve everything above the start of the region. */
+		if (pend_avail - rg.paddr > reserved)
+			reserved = pend_avail - rg.paddr;
+		size_avail = pend_avail - reserved - pstart_avail;
+
+		/*
+		 * We have a kernel mapping for this already, so the
+		 * driver won't have to make one.
+		 */
+		rg.vaddr = (void *)(sram_vstart + rg.paddr - sram_pstart);
+		omapfb_config.mem_desc.region[i] = rg;
+		configured_regions++;
+	}
+	omapfb_config.mem_desc.region_cnt = i;
+	if (reserved)
+		pr_info("Reserving %lu bytes SRAM for frame buffer\n",
+			 reserved);
+	return reserved;
 }
 
 void omapfb_set_ctrl_platform_data(void *data)
@@ -104,10 +306,19 @@ static inline int omap_init_fb(void)
 {
 	const struct omap_lcd_config *conf;
 
+	if (config_invalid)
+		return 0;
+	if (configured_regions != omapfb_config.mem_desc.region_cnt) {
+		printk(KERN_ERR "Invalid FB mem configuration entries\n");
+		return 0;
+	}
 	conf = omap_get_config(OMAP_TAG_LCD, struct omap_lcd_config);
-	if (conf == NULL)
+	if (conf == NULL) {
+		if (configured_regions)
+			/* FB mem config, but no LCD config? */
+			printk(KERN_ERR "Missing LCD configuration\n");
 		return 0;
-
+	}
 	omapfb_config.lcd = *conf;
 
 	return platform_device_register(&omap_fb_device);
@@ -117,7 +328,13 @@ arch_initcall(omap_init_fb);
 
 #else
 
-void omapfb_reserve_mem(void) {}
+void omapfb_reserve_sdram(void) {}
+unsigned long omapfb_reserve_sram(unsigned long sram_pstart,
+				  unsigned long sram_vstart,
+				  unsigned long sram_size,
+				  unsigned long start_avail,
+				  unsigned long size_avail) {}
+
 
 #endif