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 a302d9194f57..469f580ca057 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