efDataDiscreteRateMining rtuTemperatureHumidityDataOperation.c 袁明明 commit at 2020-11-09

efDataDiscreteRateMining/databaseOperation/rtuTemperatureHumidityDataOperation.c

@@ -473,3 +473,177 @@ free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
 
 	/*
+	 * If there are free pages between these,
+	 * free the section of the memmap array.
+	 */
+	if (pg < pgend)
+		free_bootmem(pg, pgend - pg);
+}
+
+/*
+ * The mem_map array can get very big.  Free the unused area of the memory map.
+ */
+static void __init free_unused_memmap(struct meminfo *mi)
+{
+	unsigned long bank_start, prev_bank_end = 0;
+	unsigned int i;
+
+	/*
+	 * This relies on each bank being in address order.
+	 * The banks are sorted previously in bootmem_init().
+	 */
+	for_each_bank(i, mi) {
+		struct membank *bank = &mi->bank[i];
+
+		bank_start = bank_pfn_start(bank);
+
+#ifdef CONFIG_SPARSEMEM
+		/*
+		 * Take care not to free memmap entries that don't exist
+		 * due to SPARSEMEM sections which aren't present.
+		 */
+		bank_start = min(bank_start,
+				 ALIGN(prev_bank_end, PAGES_PER_SECTION));
+#else
+		/*
+		 * Align down here since the VM subsystem insists that the
+		 * memmap entries are valid from the bank start aligned to
+		 * MAX_ORDER_NR_PAGES.
+		 */
+		bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES);
+#endif
+		/*
+		 * If we had a previous bank, and there is a space
+		 * between the current bank and the previous, free it.
+		 */
+		if (prev_bank_end && prev_bank_end < bank_start)
+			free_memmap(prev_bank_end, bank_start);
+
+		/*
+		 * Align up here since the VM subsystem insists that the
+		 * memmap entries are valid from the bank end aligned to
+		 * MAX_ORDER_NR_PAGES.
+		 */
+		prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
+	}
+
+#ifdef CONFIG_SPARSEMEM
+	if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
+		free_memmap(prev_bank_end,
+			    ALIGN(prev_bank_end, PAGES_PER_SECTION));
+#endif
+}
+
+static void __init free_highpages(void)
+{
+#ifdef CONFIG_HIGHMEM
+	unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
+	struct memblock_region *mem, *res;
+
+	/* set highmem page free */
+	for_each_memblock(memory, mem) {
+		unsigned long start = memblock_region_memory_base_pfn(mem);
+		unsigned long end = memblock_region_memory_end_pfn(mem);
+
+		/* Ignore complete lowmem entries */
+		if (end <= max_low)
+			continue;
+
+		/* Truncate partial highmem entries */
+		if (start < max_low)
+			start = max_low;
+
+		/* Find and exclude any reserved regions */
+		for_each_memblock(reserved, res) {
+			unsigned long res_start, res_end;
+
+			res_start = memblock_region_reserved_base_pfn(res);
+			res_end = memblock_region_reserved_end_pfn(res);
+
+			if (res_end < start)
+				continue;
+			if (res_start < start)
+				res_start = start;
+			if (res_start > end)
+				res_start = end;
+			if (res_end > end)
+				res_end = end;
+			if (res_start != start)
+				totalhigh_pages += free_area(start, res_start,
+							     NULL);
+			start = res_end;
+			if (start == end)
+				break;
+		}
+
+		/* And now free anything which remains */
+		if (start < end)
+			totalhigh_pages += free_area(start, end, NULL);
+	}
+	totalram_pages += totalhigh_pages;
+#endif
+}
+
+/*
+ * mem_init() marks the free areas in the mem_map and tells us how much
+ * memory is free.  This is done after various parts of the system have
+ * claimed their memory after the kernel image.
+ */
+void __init mem_init(void)
+{
+	unsigned long reserved_pages, free_pages;
+	struct memblock_region *reg;
+	int i;
+#ifdef CONFIG_HAVE_TCM
+	/* These pointers are filled in on TCM detection */
+	extern u32 dtcm_end;
+	extern u32 itcm_end;
+#endif
+
+	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
+
+	/* this will put all unused low memory onto the freelists */
+	free_unused_memmap(&meminfo);
+
+	totalram_pages += free_all_bootmem();
+
+#ifdef CONFIG_SA1111
+	/* now that our DMA memory is actually so designated, we can free it */
+	totalram_pages += free_area(PHYS_PFN_OFFSET,
+				    __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
+#endif
+
+	free_highpages();
+
+	reserved_pages = free_pages = 0;
+
+	for_each_bank(i, &meminfo) {
+		struct membank *bank = &meminfo.bank[i];
+		unsigned int pfn1, pfn2;
+		struct page *page, *end;
+
+		pfn1 = bank_pfn_start(bank);
+		pfn2 = bank_pfn_end(bank);
+
+		page = pfn_to_page(pfn1);
+		end  = pfn_to_page(pfn2 - 1) + 1;
+
+		do {
+			if (PageReserved(page))
+				reserved_pages++;
+			else if (!page_count(page))
+				free_pages++;
+			page++;
+		} while (page < end);
+	}
+
+	/*
+	 * Since our memory may not be contiguous, calculate the
+	 * real number of pages we have in this system
+	 */
+	printk(KERN_INFO "Memory:");
+	num_physpages = 0;
+	for_each_memblock(memory, reg) {
+		unsigned long pages = memblock_region_memory_end_pfn(reg) -
+			memblock_region_memory_base_pfn(reg);
+		num_physpages += pages;