[PATCH 2/3] MIPS: sgi-ip32: Reserve the firmware memory

[Imre Kaloz]

ARC memory descriptors are ignored on IP32, so firmware data in low
memory ends up in the page allocator and CMA. Reserve it using the
generic ARC walk; RAM comes from CRIME, as ARC lists only the first
256 MiB.

Signed-off-by: Imre Kaloz <kaloz@xxxxxxxxxx>
---
 arch/mips/fw/arc/memory.c        | 11 +++++++++--
 arch/mips/include/asm/sgialib.h  |  3 +++
 arch/mips/sgi-ip32/ip32-memory.c |  3 +++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/mips/fw/arc/memory.c b/arch/mips/fw/arc/memory.c
index fb78e6fd5de4..97eb7ba02cd4 100644
--- a/arch/mips/fw/arc/memory.c
+++ b/arch/mips/fw/arc/memory.c
@@ -120,7 +120,8 @@ static int __init prom_memtype_classify(union linux_memtypes type)
 	return memtype_classify_arc(type);
 }
 
-void __weak __init prom_meminit(void)
+/* Platforms that detect RAM themselves pass add_ram = false. */
+void __init prom_mdesc_init(bool add_ram)
 {
 	struct linux_mdesc *p;
 
@@ -151,7 +152,8 @@ void __weak __init prom_meminit(void)
 		if (base < PHYS_OFFSET)
 			continue;
 
-		memblock_add(base, size);
+		if (add_ram)
+			memblock_add(base, size);
 
 		if (type == mem_reserved)
 			memblock_reserve(base, size);
@@ -169,6 +171,11 @@ void __weak __init prom_meminit(void)
 	}
 }
 
+void __weak __init prom_meminit(void)
+{
+	prom_mdesc_init(true);
+}
+
 void __weak __init prom_cleanup(void)
 {
 }
diff --git a/arch/mips/include/asm/sgialib.h b/arch/mips/include/asm/sgialib.h
index 80f900417f7e..28fd9f6fbad2 100644
--- a/arch/mips/include/asm/sgialib.h
+++ b/arch/mips/include/asm/sgialib.h
@@ -36,6 +36,9 @@ extern struct linux_mdesc *prom_getmdesc(struct linux_mdesc *curr);
  */
 extern void prom_meminit(void);
 
+/* Reserve the firmware's memory; add_ram also registers all ranges as RAM. */
+void prom_mdesc_init(bool add_ram);
+
 /* PROM device tree library routines. */
 #define PROM_NULL_COMPONENT ((pcomponent *) 0)
 
diff --git a/arch/mips/sgi-ip32/ip32-memory.c b/arch/mips/sgi-ip32/ip32-memory.c
index 5fee33744f67..eadafb98422e 100644
--- a/arch/mips/sgi-ip32/ip32-memory.c
+++ b/arch/mips/sgi-ip32/ip32-memory.c
@@ -40,4 +40,7 @@ void __init prom_meminit(void)
 			bank, base, size >> 20);
 		memblock_add(base, size);
 	}
+
+	/* ARC describes only the first 256 MiB, so RAM comes from CRIME. */
+	prom_mdesc_init(false);
 }
-- 
2.47.3