[PATCH 19/22] x86, lmb: Add lmb_find_area_size()

From: Yinghai Lu
Date: Sat May 08 2010 - 11:22:32 EST


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 mm/lmb.c yet.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/mm/Makefile | 2 +
arch/x86/mm/lmb.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 90 insertions(+), 0 deletions(-)
create mode 100644 arch/x86/mm/lmb.c

diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index a4c7683..8ab0505 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-$(CONFIG_HAVE_LMB) += lmb.o
+
obj-$(CONFIG_MEMTEST) += memtest.o
diff --git a/arch/x86/mm/lmb.c b/arch/x86/mm/lmb.c
new file mode 100644
index 0000000..902b6ea
--- /dev/null
+++ b/arch/x86/mm/lmb.c
@@ -0,0 +1,88 @@
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/lmb.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)
+{
+ int i;
+ u64 addr = *addrp, last;
+ u64 size = *sizep;
+ bool changed = false;
+again:
+ last = addr + size;
+ for (i = 0; i < lmb.reserved.cnt && lmb.reserved.region[i].size; i++) {
+ struct lmb_property *r = &lmb.reserved.region[i];
+ 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 __lmb_find_area_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 LMB_ERROR;
+}
+
+/*
+ * Find next free range after *start
+ */
+u64 __init lmb_find_area_size(u64 start, u64 *sizep, u64 align)
+{
+ int i;
+
+ for (i = 0; i < lmb.memory.cnt; i++) {
+ u64 ei_start = lmb.memory.region[i].base;
+ u64 ei_last = ei_start + lmb.memory.region[i].size;
+ u64 addr;
+
+ addr = __lmb_find_area_size(ei_start, ei_last, start,
+ sizep, align);
+
+ if (addr != LMB_ERROR)
+ return addr;
+ }
+
+ return LMB_ERROR;
+}
+
--
1.6.4.2

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