[REPOST PATCH v07 2/5] powerpc/drmem: Add internal_flags feature

[Michael Bringmann <mwb@linux.vnet.ibm.com>]

powerpc/drmem: Add internal_flags field to each LMB to allow
marking of kernel software-specific operations that need not
be exported to other users.  For instance, if information about
selected LMBs needs to be maintained for subsequent passes
through the system, it can be encoded into the LMB array itself
without requiring the allocation and maintainance of additional
data structures.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in v04:
  -- Add another initialization of 'lmb->internal_flags' to
     init_drmem_v2_lmbs.
---
 arch/powerpc/include/asm/drmem.h |   18 ++++++++++++++++++
 arch/powerpc/mm/drmem.c          |    3 +++
 2 files changed, 21 insertions(+)

diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index cfe8598..dbb3e6c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -17,6 +17,7 @@ struct drmem_lmb {
 	u32     drc_index;
 	u32     aa_index;
 	u32     flags;
+	u32     internal_flags;
 };
 
 struct drmem_lmb_info {
@@ -94,6 +95,23 @@ static inline bool drmem_lmb_reserved(struct drmem_lmb *lmb)
 	return lmb->flags & DRMEM_LMB_RESERVED;
 }
 
+#define DRMEM_LMBINT_UPDATE	0x00000001
+
+static inline void drmem_mark_lmb_update(struct drmem_lmb *lmb)
+{
+	lmb->internal_flags |= DRMEM_LMBINT_UPDATE;
+}
+
+static inline void drmem_remove_lmb_update(struct drmem_lmb *lmb)
+{
+	lmb->internal_flags &= ~DRMEM_LMBINT_UPDATE;
+}
+
+static inline bool drmem_lmb_update(struct drmem_lmb *lmb)
+{
+	return lmb->internal_flags & DRMEM_LMBINT_UPDATE;
+}
+
 u64 drmem_lmb_memory_max(void);
 void __init walk_drmem_lmbs(struct device_node *dn,
 			void (*func)(struct drmem_lmb *, const __be32 **));
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index ded9dbf..f199fe5 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -207,6 +207,7 @@ static void read_drconf_v1_cell(struct drmem_lmb *lmb,
 
 	lmb->aa_index = of_read_number(p++, 1);
 	lmb->flags = of_read_number(p++, 1);
+	lmb->internal_flags = 0;
 
 	*prop = p;
 }
@@ -265,6 +266,7 @@ static void __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
 
 			lmb.aa_index = dr_cell.aa_index;
 			lmb.flags = dr_cell.flags;
+			lmb.internal_flags = 0;
 
 			func(&lmb, &usm);
 		}
@@ -441,6 +443,7 @@ static void init_drmem_v2_lmbs(const __be32 *prop,
 
 			lmb->aa_index = dr_cell.aa_index;
 			lmb->flags = dr_cell.flags;
+			lmb->internal_flags = 0;
 		}
 	}
 }