x86/mm: Introduce max_possible_pfn

max_possible_pfn will be used for tracking max possible
PFN for memory that isn't present in E820 table and
could be hotplugged later.

By default max_possible_pfn is initialized with max_pfn,
but later it could be updated with highest PFN of
hotpluggable memory ranges declared in ACPI SRAT table
if any present.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: konrad.wilk@oracle.com
Cc: pbonzini@redhat.com
Cc: revers@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1449234426-273049-2-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 29db25f..16a8465 100644 (file)
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1048,6 +1048,8 @@ void __init setup_arch(char **cmdline_p)
        if (mtrr_trim_uncached_memory(max_pfn))
                max_pfn = e820_end_of_ram_pfn();
 
+       max_possible_pfn = max_pfn;
+
 #ifdef CONFIG_X86_32
        /* max_low_pfn get updated here */
        find_low_pfn_range();

diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index c2aea63..b5f8218 100644 (file)
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -203,6 +203,8 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
                pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n",
                        (unsigned long long)start, (unsigned long long)end - 1);
 
+       max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
+
        return 0;
 out_err_bad_srat:
        bad_srat();

diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index f589222..35b22f9 100644 (file)
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -19,6 +19,10 @@ extern unsigned long min_low_pfn;
  * highest page
  */
 extern unsigned long max_pfn;
+/*
+ * highest possible page
+ */
+extern unsigned long long max_possible_pfn;
 
 #ifndef CONFIG_NO_BOOTMEM
 /*

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 3b63807..91e32bc 100644 (file)
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -33,6 +33,7 @@ EXPORT_SYMBOL(contig_page_data);
 unsigned long max_low_pfn;
 unsigned long min_low_pfn;
 unsigned long max_pfn;
+unsigned long long max_possible_pfn;
 
 bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
 

diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index e57cf24..99feb2b 100644 (file)
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -31,6 +31,7 @@ EXPORT_SYMBOL(contig_page_data);
 unsigned long max_low_pfn;
 unsigned long min_low_pfn;
 unsigned long max_pfn;
+unsigned long long max_possible_pfn;
 
 static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
                                        u64 goal, u64 limit)