msm: Allow lowmem to be non contiguous and mixed.

Any image that is expected to have a lifetime of
the entire system can give the virtual address
space back for use in vmalloc.

Change-Id: I81ce848cd37e8573d706fa5d1aa52147b3c8da12
Signed-off-by: Neeti Desai <neetid@codeaurora.org>

arch/arm/mm/ioremap.c

@@ -91,6 +91,8 @@ void __init add_static_vm_early(struct static_vm *svm)
 	void *vaddr;
 
 	vm = &svm->vm;
+	if (vm_area_check_early(vm))
+		return;
 	vm_area_add_early(vm);
 	vaddr = vm->addr;
 

arch/arm/mm/mmu.c

@@ -1459,12 +1459,21 @@ extern char __init_data[];
 static void __init map_lowmem(void)
 {
 	struct memblock_region *reg;
+	struct vm_struct *vm;
+	phys_addr_t start;
+	phys_addr_t end;
+	unsigned long vaddr;
+	unsigned long pfn;
+	unsigned long length;
+	unsigned int type;
+	int nr = 0;
 
 	/* Map all the lowmem memory banks. */
 	for_each_memblock(memory, reg) {
-		phys_addr_t start = reg->base;
-		phys_addr_t end = start + reg->size;
 		struct map_desc map;
+		nr++;
+		start = reg->base;
+		end = start + reg->size;
 
 		if (end > arm_lowmem_limit)
 			end = arm_lowmem_limit;
@@ -1516,6 +1525,32 @@ static void __init map_lowmem(void)
 
 		create_mapping(&map);
 	}
+
+	vm = early_alloc_aligned(sizeof(*vm) * nr, __alignof__(*vm));
+
+	for_each_memblock(memory, reg) {
+
+		start = reg->base;
+		end = start + reg->size;
+
+		if (end > arm_lowmem_limit)
+			end = arm_lowmem_limit;
+		if (start >= end)
+			break;
+
+		pfn = __phys_to_pfn(start);
+		vaddr = __phys_to_virt(start);
+		length = end - start;
+		type = MT_MEMORY;
+
+		vm->addr = (void *)(vaddr & PAGE_MASK);
+		vm->size = PAGE_ALIGN(length + (vaddr & ~PAGE_MASK));
+		vm->phys_addr = __pfn_to_phys(pfn);
+		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+		vm->flags |= VM_ARM_MTYPE(type);
+		vm->caller = map_lowmem;
+		vm_area_add_early(vm++);
+	}
 }
 
 /*

include/linux/vmalloc.h

@@ -146,6 +146,7 @@ extern long vwrite(char *buf, char *addr, unsigned long count);
 extern struct list_head vmap_area_list;
 extern __init void vm_area_add_early(struct vm_struct *vm);
 extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
+extern __init int vm_area_check_early(struct vm_struct *vm);
 
 #ifdef CONFIG_SMP
 # ifdef CONFIG_MMU

mm/vmalloc.c

@@ -1136,6 +1136,33 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro
 EXPORT_SYMBOL(vm_map_ram);
 
 static struct vm_struct *vmlist __initdata;
+
+/**
+ * vm_area_check_early - check if vmap area is already mapped
+ * @vm: vm_struct to be checked
+ *
+ * This function is used to check if the vmap area has been
+ * mapped already. @vm->addr, @vm->size and @vm->flags should
+ * contain proper values.
+ *
+ */
+int __init vm_area_check_early(struct vm_struct *vm)
+{
+	struct vm_struct *tmp, **p;
+
+	BUG_ON(vmap_initialized);
+	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+		if (tmp->addr >= vm->addr) {
+			if (tmp->addr < vm->addr + vm->size)
+				return 1;
+		} else {
+			if (tmp->addr + tmp->size > vm->addr)
+				return 1;
+		}
+	}
+	return 0;
+}
+
 /**
  * vm_area_add_early - add vmap area early during boot
  * @vm: vm_struct to add