lmb: notify of any changes to the LMB memory map

In U-Boot, LMB and EFI are two primary modules who provide memory
allocation and reservation API's. Both these modules operate with the
same regions of memory for allocations. Use the LMB memory map update
event to notify other interested listeners about a change in it's
memory map. This can then be used by the other module to keep track of
available and used memory.

There is no need to send these notifications when the LMB module is
being unit-tested. Add a flag to the lmb structure to indicate if the
memory map is being used for tests, and suppress sending any
notifications when running these unit tests.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 511281e..ac20395 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -784,6 +784,20 @@
 				uint32_t *descriptor_version);
 /* Adds a range into the EFI memory map */
 efi_status_t efi_add_memory_map(u64 start, u64 size, int memory_type);
+
+/**
+ * efi_add_memory_map_pg() - add pages to the memory map
+ *
+ * @start:		start address, must be a multiple of EFI_PAGE_SIZE
+ * @pages:		number of pages to add
+ * @memory_type:	type of memory added
+ * @overlap_only_ram:	region may only overlap RAM
+ * Return:		status code
+ */
+efi_status_t efi_add_memory_map_pg(u64 start, u64 pages,
+					  int memory_type,
+					  bool overlap_only_ram);
+
 /* Adds a conventional range into the EFI memory map */
 efi_status_t efi_add_conventional_memory_map(u64 ram_start, u64 ram_end,
 					     u64 ram_top);
diff --git a/include/lmb.h b/include/lmb.h
index ec477c1..8370021 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -46,10 +46,12 @@
  *
  * @free_mem:	List of free memory regions
  * @used_mem:	List of used/reserved memory regions
+ * @test:	Is structure being used for LMB tests
  */
 struct lmb {
 	struct alist free_mem;
 	struct alist used_mem;
+	bool test;
 };
 
 /**
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index aa1da21..41501e9 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -264,7 +264,7 @@
  * @overlap_only_ram:	region may only overlap RAM
  * Return:		status code
  */
-static efi_status_t efi_add_memory_map_pg(u64 start, u64 pages,
+efi_status_t efi_add_memory_map_pg(u64 start, u64 pages,
 					  int memory_type,
 					  bool overlap_only_ram)
 {
diff --git a/lib/lmb.c b/lib/lmb.c
index 0504a7b..e7167f8 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -8,6 +8,7 @@
 
 #include <alist.h>
 #include <efi_loader.h>
+#include <event.h>
 #include <image.h>
 #include <mapmem.h>
 #include <lmb.h>
@@ -22,11 +23,52 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#define MAP_OP_RESERVE		(u8)0x1
+#define MAP_OP_FREE		(u8)0x2
+#define MAP_OP_ADD		(u8)0x3
+
 #define LMB_ALLOC_ANYWHERE	0
 #define LMB_ALIST_INITIAL_SIZE	4
 
 static struct lmb lmb;
 
+static bool lmb_should_notify(enum lmb_flags flags)
+{
+	return !lmb.test && !(flags & LMB_NONOTIFY) &&
+		CONFIG_IS_ENABLED(EFI_LOADER);
+}
+
+static int __maybe_unused lmb_map_update_notify(phys_addr_t addr,
+						phys_size_t size,
+						u8 op)
+{
+	u64 efi_addr;
+	u64 pages;
+	efi_status_t status;
+
+	if (op != MAP_OP_RESERVE && op != MAP_OP_FREE && op != MAP_OP_ADD) {
+		log_err("Invalid map update op received (%d)\n", op);
+		return -1;
+	}
+
+	efi_addr = (uintptr_t)map_sysmem(addr, 0);
+	pages = efi_size_in_pages(size + (efi_addr & EFI_PAGE_MASK));
+	efi_addr &= ~EFI_PAGE_MASK;
+
+	status = efi_add_memory_map_pg(efi_addr, pages,
+				       op == MAP_OP_RESERVE ?
+				       EFI_BOOT_SERVICES_DATA :
+				       EFI_CONVENTIONAL_MEMORY,
+				       false);
+	if (status != EFI_SUCCESS) {
+		log_err("%s: LMB Map notify failure %lu\n", __func__,
+			status & ~EFI_ERROR_MASK);
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
 static void lmb_print_region_flags(enum lmb_flags flags)
 {
 	u64 bitpos;
@@ -473,9 +515,17 @@
 /* This routine may be called with relocation disabled. */
 long lmb_add(phys_addr_t base, phys_size_t size)
 {
+	long ret;
 	struct alist *lmb_rgn_lst = &lmb.free_mem;
 
-	return lmb_add_region(lmb_rgn_lst, base, size);
+	ret = lmb_add_region(lmb_rgn_lst, base, size);
+	if (ret)
+		return ret;
+
+	if (lmb_should_notify(LMB_NONE))
+		return lmb_map_update_notify(base, size, MAP_OP_ADD);
+
+	return 0;
 }
 
 static long __lmb_free(phys_addr_t base, phys_size_t size)
@@ -529,11 +579,6 @@
 				    rgn[i].flags);
 }
 
-long lmb_free(phys_addr_t base, phys_size_t size)
-{
-	return __lmb_free(base, size);
-}
-
 /**
  * lmb_free_flags() - Free up a region of memory
  * @base: Base Address of region to be freed
@@ -545,16 +590,38 @@
  * Return: 0 if successful, -1 on failure
  */
 long lmb_free_flags(phys_addr_t base, phys_size_t size,
-		    __always_unused uint flags)
+		    uint flags)
 {
-	return __lmb_free(base, size);
+	long ret;
+
+	ret = __lmb_free(base, size);
+	if (ret < 0)
+		return ret;
+
+	if (lmb_should_notify(flags))
+		return lmb_map_update_notify(base, size, MAP_OP_FREE);
+
+	return ret;
 }
 
+long lmb_free(phys_addr_t base, phys_size_t size)
+{
+	return lmb_free_flags(base, size, LMB_NONE);
+}
+
 long lmb_reserve_flags(phys_addr_t base, phys_size_t size, enum lmb_flags flags)
 {
+	long ret = 0;
 	struct alist *lmb_rgn_lst = &lmb.used_mem;
 
+	ret = lmb_add_region_flags(lmb_rgn_lst, base, size, flags);
+	if (ret < 0)
+		return -1;
+
+	if (lmb_should_notify(flags))
+		return lmb_map_update_notify(base, size, MAP_OP_RESERVE);
+
-	return lmb_add_region_flags(lmb_rgn_lst, base, size, flags);
+	return ret;
 }
 
 long lmb_reserve(phys_addr_t base, phys_size_t size)
@@ -586,6 +653,8 @@
 static phys_addr_t __lmb_alloc_base(phys_size_t size, ulong align,
 				    phys_addr_t max_addr, enum lmb_flags flags)
 {
+	u8 op;
+	int ret;
 	long i, rgn;
 	phys_addr_t base = 0;
 	phys_addr_t res_base;
@@ -616,6 +685,15 @@
 				if (lmb_add_region_flags(&lmb.used_mem, base,
 							 size, flags) < 0)
 					return 0;
+
+				if (lmb_should_notify(flags)) {
+					op = MAP_OP_RESERVE;
+					ret = lmb_map_update_notify(base, size,
+								    op);
+					if (ret)
+						return ret;
+				}
+
 				return base;
 			}
 
@@ -785,7 +863,7 @@
 	return 0;
 }
 
-static int lmb_setup(void)
+static int lmb_setup(bool test)
 {
 	bool ret;
 
@@ -803,6 +881,8 @@
 		return -ENOMEM;
 	}
 
+	lmb.test = test;
+
 	return 0;
 }
 
@@ -822,7 +902,7 @@
 {
 	int ret;
 
-	ret = lmb_setup();
+	ret = lmb_setup(false);
 	if (ret) {
 		log_info("Unable to init LMB\n");
 		return ret;
@@ -850,7 +930,7 @@
 	int ret;
 
 	*store = lmb;
-	ret = lmb_setup();
+	ret = lmb_setup(true);
 	if (ret)
 		return ret;