x86, memblock: Add memblock_x86_find_in_range_size()

size is returned according free range.
Will be used to find free ranges for early_memtest and memory corruption check

Do not mess it up with lib/memblock.c yet.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 97 insertions, 0 deletions

diff --git a/arch/x86/include/asm/memblock.h b/arch/x86/include/asm/memblock.h
new file mode 100644
index 000000000000..c14219a26168
--- /dev/null
+++ b/arch/x86/include/asm/memblock.h
@@ -0,0 +1,8 @@
+#ifndef _X86_MEMBLOCK_H
+#define _X86_MEMBLOCK_H
+
+#define ARCH_DISCARD_MEMBLOCK
+
+u64 memblock_x86_find_in_range_size(u64 start, u64 *sizep, u64 align);
+
+#endif
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index a4c768397baa..55543397a8a7 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -26,4 +26,6 @@ obj-$(CONFIG_NUMA)		+= numa.o numa_$(BITS).o
 obj-$(CONFIG_K8_NUMA)           += k8topology_64.o
 obj-$(CONFIG_ACPI_NUMA)         += srat_$(BITS).o
 
+obj-$(CONFIG_HAVE_MEMBLOCK)             += memblock.o
+
 obj-$(CONFIG_MEMTEST)           += memtest.o
diff --git a/arch/x86/mm/memblock.c b/arch/x86/mm/memblock.c
new file mode 100644
index 000000000000..26ba46234cba
--- /dev/null
+++ b/arch/x86/mm/memblock.c
@@ -0,0 +1,87 @@
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+#include <linux/mm.h>
+#include <linux/range.h>
+
+/* Check for already reserved areas */
+static inline bool __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align)
+{
+        struct memblock_region *r;
+        u64 addr = *addrp, last;
+        u64 size = *sizep;
+        bool changed = false;
+
+again:
+        last = addr + size;
+        for_each_memblock(reserved, r) {
+                if (last > r->base && addr < r->base) {
+                        size = r->base - addr;
+                        changed = true;
+                        goto again;
+                }
+                if (last > (r->base + r->size) && addr < (r->base + r->size)) {
+                        addr = round_up(r->base + r->size, align);
+                        size = last - addr;
+                        changed = true;
+                        goto again;
+                }
+                if (last <= (r->base + r->size) && addr >= r->base) {
+                        (*sizep)++;
+                        return false;
+                }
+        }
+        if (changed) {
+                *addrp = addr;
+                *sizep = size;
+        }
+        return changed;
+}
+
+static u64 __init __memblock_x86_find_in_range_size(u64 ei_start, u64 ei_last, u64 start,
+                         u64 *sizep, u64 align)
+{
+        u64 addr, last;
+
+        addr = round_up(ei_start, align);
+        if (addr < start)
+                addr = round_up(start, align);
+        if (addr >= ei_last)
+                goto out;
+        *sizep = ei_last - addr;
+        while (bad_addr_size(&addr, sizep, align) && addr + *sizep <= ei_last)
+                ;
+        last = addr + *sizep;
+        if (last > ei_last)
+                goto out;
+
+        return addr;
+
+out:
+        return MEMBLOCK_ERROR;
+}
+
+/*
+ * Find next free range after start, and size is returned in *sizep
+ */
+u64 __init memblock_x86_find_in_range_size(u64 start, u64 *sizep, u64 align)
+{
+        struct memblock_region *r;
+
+        for_each_memblock(memory, r) {
+                u64 ei_start = r->base;
+                u64 ei_last = ei_start + r->size;
+                u64 addr;
+
+                addr = __memblock_x86_find_in_range_size(ei_start, ei_last, start,
+                                         sizep, align);
+
+                if (addr != MEMBLOCK_ERROR)
+                        return addr;
+        }
+
+        return MEMBLOCK_ERROR;
+}