msm: 8974: Add function to reserve memory from device tree

Memory reservations for memory pools or using memblock remove
must happen early at bootup. Add a function at early boot to
walk the flattened device tree and extract memory reservation
information from appropriate bindings in device tree. To ensure
that the memory is only reserved when a driver is enabled,
drivers must put EXPORT_COMPAT(<compat string>) in the driver
as well as adding the binding to the device tree. More
documentation is available in
Documentation/devicetree/bindings/arm/msm/memory-reserve.txt

Change-Id: I28fa71d7a30cea9af5447acb5d2dde562fa0f6de
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

arch/arm/kernel/vmlinux.lds.S

@@ -185,6 +185,7 @@ SECTIONS
 		INIT_SETUP(16)
 		INIT_CALLS
 		CON_INITCALL
+		COMPAT_EXPORTS
 		SECURITY_INITCALL
 		INIT_RAM_FS
 	}

arch/arm/mach-msm/board-8974.c

@@ -383,6 +383,7 @@ static struct reserve_info msm_8974_reserve_info __initdata = {
 static void __init msm_8974_early_memory(void)
 {
 	reserve_info = &msm_8974_reserve_info;
+	of_scan_flat_dt(dt_scan_for_memory_reserve, msm_8974_reserve_table);
 }
 
 void __init msm_8974_reserve(void)

arch/arm/mach-msm/include/mach/memory.h

@@ -118,6 +118,23 @@ void find_membank0_hole(void);
 	(virt) - MEMBANK0_PAGE_OFFSET + MEMBANK0_PHYS_OFFSET)
 #endif
 
+/*
+ * Need a temporary unique variable that no one will ever see to
+ * hold the compat string. Line number gives this easily.
+ * Need another layer of indirection to get __LINE__ to expand
+ * properly as opposed to appending and ending up with
+ * __compat___LINE__
+ */
+#define __CONCAT(a, b)	___CONCAT(a, b)
+#define ___CONCAT(a, b)	a ## b
+
+#define EXPORT_COMPAT(com)	\
+static char *__CONCAT(__compat_, __LINE__)  __used \
+	__attribute((__section__(".exportcompat.init"))) = com
+
+extern char *__compat_exports_start[];
+extern char *__compat_exports_end[];
+
 #endif
 
 #if defined CONFIG_ARCH_MSM_SCORPION || defined CONFIG_ARCH_MSM_KRAIT
@@ -135,4 +152,5 @@ void find_membank0_hole(void);
 
 #ifndef CONFIG_ARCH_MSM7X27
 #define CONSISTENT_DMA_SIZE	(SZ_1M * 14)
+
 #endif

arch/arm/mach-msm/include/mach/msm_memtypes.h

@@ -66,5 +66,8 @@ struct reserve_info {
 
 extern struct reserve_info *reserve_info;
 
+int __init dt_scan_for_memory_reserve(unsigned long node, const char *uname,
+					int depth, void *data);
+
 unsigned long __init reserve_memory_for_fmem(unsigned long, unsigned long);
 #endif

arch/arm/mach-msm/memory.c

@@ -37,6 +37,7 @@
 #include <mach/msm_iomap.h>
 #include <mach/socinfo.h>
 #include <linux/sched.h>
+#include <linux/of_fdt.h>
 
 /* fixme */
 #include <asm/tlbflush.h>
@@ -381,3 +382,117 @@ int release_fmem_c_region(void *unused)
 {
 	return fmem_set_state(FMEM_T_STATE);
 }
+
+static char * const memtype_names[] = {
+	[MEMTYPE_SMI_KERNEL] = "SMI_KERNEL",
+	[MEMTYPE_SMI]	= "SMI",
+	[MEMTYPE_EBI0] = "EBI0",
+	[MEMTYPE_EBI1] = "EBI1",
+};
+
+static int reserve_memory_type(char *mem_name,
+				struct memtype_reserve *reserve_table,
+				int size)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(memtype_names); i++) {
+		if (memtype_names[i] && strcmp(mem_name,
+				memtype_names[i]) == 0) {
+			reserve_table[i].size += size;
+			return 0;
+		}
+	}
+
+	pr_err("Could not find memory type %s\n", mem_name);
+	return -EINVAL;
+}
+
+static int check_for_compat(unsigned long node)
+{
+	char **start = __compat_exports_start;
+
+	for ( ; start < __compat_exports_end; start++)
+		if (of_flat_dt_is_compatible(node, *start))
+			return 1;
+
+	return 0;
+}
+
+int __init dt_scan_for_memory_reserve(unsigned long node, const char *uname,
+		int depth, void *data)
+{
+	char *memory_name_prop;
+	unsigned int *memory_remove_prop;
+	unsigned long memory_name_prop_length;
+	unsigned long memory_remove_prop_length;
+	unsigned long memory_size_prop_length;
+	unsigned int *memory_size_prop;
+	unsigned int memory_size;
+	unsigned int memory_start;
+	int ret;
+
+	memory_name_prop = of_get_flat_dt_prop(node,
+						"qcom,memory-reservation-type",
+						&memory_name_prop_length);
+	memory_remove_prop = of_get_flat_dt_prop(node,
+						"qcom,memblock-remove",
+						&memory_remove_prop_length);
+
+	if (memory_name_prop || memory_remove_prop) {
+		if (!check_for_compat(node))
+			goto out;
+	} else {
+		goto out;
+	}
+
+	if (memory_name_prop) {
+		if (strnlen(memory_name_prop, memory_name_prop_length) == 0) {
+			WARN(1, "Memory name was malformed\n");
+			goto mem_remove;
+		}
+
+		memory_size_prop = of_get_flat_dt_prop(node,
+						"qcom,memory-reservation-size",
+						&memory_size_prop_length);
+
+		if (memory_size_prop &&
+		    (memory_size_prop_length == sizeof(unsigned int))) {
+			memory_size = be32_to_cpu(*memory_size_prop);
+
+			if (reserve_memory_type(memory_name_prop,
+						data, memory_size) == 0)
+				pr_info("%s reserved %s size %x\n",
+					uname, memory_name_prop, memory_size);
+			else
+				WARN(1, "Node %s reserve failed\n",
+						uname);
+		} else {
+			WARN(1, "Node %s specified bad/nonexistent size\n",
+					uname);
+		}
+	}
+
+mem_remove:
+
+	if (memory_remove_prop) {
+		if (memory_remove_prop_length != (2*sizeof(unsigned int))) {
+			WARN(1, "Memory remove malformed\n");
+			goto out;
+		}
+
+		memory_start = be32_to_cpu(memory_remove_prop[0]);
+		memory_size = be32_to_cpu(memory_remove_prop[1]);
+
+		ret = memblock_remove(memory_start, memory_size);
+		if (ret)
+			WARN(1, "Failed to remove memory %x-%x\n",
+				memory_start, memory_start+memory_size);
+		else
+			pr_info("Node %s removed memory %x-%x\n", uname,
+				memory_start, memory_start+memory_size);
+	}
+
+out:
+	return 0;
+}

include/asm-generic/vmlinux.lds.h

@@ -645,6 +645,11 @@
 		*(.security_initcall.init)				\
 		VMLINUX_SYMBOL(__security_initcall_end) = .;
 
+#define COMPAT_EXPORTS							\
+		VMLINUX_SYMBOL(__compat_exports_start) = .;		\
+		*(.exportcompat.init)					\
+		VMLINUX_SYMBOL(__compat_exports_end) = .;
+
 #ifdef CONFIG_BLK_DEV_INITRD
 #define INIT_RAM_FS							\
 	. = ALIGN(4);							\