mm: cma: split cma-reserved in dmesg log

When the system boots up, in the dmesg logs we can see the memory
statistics along with total reserved as below.  Memory: 458840k/458840k
available, 65448k reserved, 0K highmem

When CMA is enabled, still the total reserved memory remains the same.
However, the CMA memory is not considered as reserved.  But, when we see
/proc/meminfo, the CMA memory is part of free memory.  This creates
confusion.  This patch corrects the problem by properly subtracting the
CMA reserved memory from the total reserved memory in dmesg logs.

Below is the dmesg snapshot from an arm based device with 512MB RAM and
12MB single CMA region.

Before this change:
  Memory: 458840k/458840k available, 65448k reserved, 0K highmem

After this change:
  Memory: 458840k/458840k available, 53160k reserved, 12288k cma-reserved, 0K highmem

Signed-off-by: Pintu Kumar <[email protected]>
Signed-off-by: Vishnu Pratap Singh <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Cc: Rafael Aquini <[email protected]>
Cc: Jerome Marchand <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

include/linux/cma.h

@@ -15,6 +15,7 @@
 
 struct cma;
 
+extern unsigned long totalcma_pages;
 extern phys_addr_t cma_get_base(struct cma *cma);
 extern unsigned long cma_get_size(struct cma *cma);
 

mm/cma.c

@@ -337,6 +337,7 @@ int __init cma_declare_contiguous(phys_addr_t base,
 	if (ret)
 		goto err;
 
+	totalcma_pages += (size / PAGE_SIZE);
 	pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
 		&base);
 	return 0;

mm/page_alloc.c

@@ -111,6 +111,7 @@ static DEFINE_SPINLOCK(managed_page_count_lock);
 
 unsigned long totalram_pages __read_mostly;
 unsigned long totalreserve_pages __read_mostly;
+unsigned long totalcma_pages __read_mostly;
 /*
  * When calculating the number of globally allowed dirty pages, there
  * is a certain number of per-zone reserves that should not be
@@ -5586,15 +5587,16 @@ void __init mem_init_print_info(const char *str)
 
 	pr_info("Memory: %luK/%luK available "
 	       "(%luK kernel code, %luK rwdata, %luK rodata, "
-	       "%luK init, %luK bss, %luK reserved"
+	       "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
 #ifdef	CONFIG_HIGHMEM
 	       ", %luK highmem"
 #endif
 	       "%s%s)\n",
 	       nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
 	       codesize >> 10, datasize >> 10, rosize >> 10,
 	       (init_data_size + init_code_size) >> 10, bss_size >> 10,
-	       (physpages - totalram_pages) << (PAGE_SHIFT-10),
+	       (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10),
+	       totalcma_pages << (PAGE_SHIFT-10),
 #ifdef	CONFIG_HIGHMEM
 	       totalhigh_pages << (PAGE_SHIFT-10),
 #endif