[PATCH 4.2.y-ckt 292/305] tile: provide CONFIG_PAGE_SIZE_64KB etc for tilepro

[Kamal Mostafa]

4.2.8-ckt2 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Chris Metcalf <cmetcalf@xxxxxxxxxx>

commit c1b27ab5d69099718f519127eea017120c180e71 upstream.

This allows the build system to know that it can't attempt to
configure the Lustre virtual block device, for example, when tilepro
is using 64KB pages (as it does by default).  The tilegx build
already provided those symbols.

Previously we required that the tilepro hypervisor be rebuilt with
a different hardcoded page size in its headers, and then Linux be
rebuilt using the updated hypervisor header.  Now we allow each of
the hypervisor and Linux to be built independently.  We still check
at boot time to ensure that the page size provided by the hypervisor
matches what Linux expects.

Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 arch/tile/Kconfig            | 11 +++++------
 arch/tile/include/asm/page.h |  8 +++++---
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 9def1f5..bd2b4cf 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -175,8 +175,6 @@ config NR_CPUS
 	  smaller kernel memory footprint results from using a smaller
 	  value on chips with fewer tiles.
 
-if TILEGX
-
 choice
 	prompt "Kernel page size"
 	default PAGE_SIZE_64KB
@@ -187,8 +185,11 @@ choice
 	  connections, etc., it may be better to select 16KB, which uses
 	  memory more efficiently at some cost in TLB performance.
 
-	  Note that this option is TILE-Gx specific; currently
-	  TILEPro page size is set by rebuilding the hypervisor.
+	  Note that for TILEPro, you must also rebuild the hypervisor
+	  with a matching page size.
+
+config PAGE_SIZE_4KB
+	bool "4KB" if TILEPRO
 
 config PAGE_SIZE_16KB
 	bool "16KB"
@@ -198,8 +199,6 @@ config PAGE_SIZE_64KB
 
 endchoice
 
-endif
-
 source "kernel/Kconfig.hz"
 
 config KEXEC
diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h
index a213a8d..8eca6a0 100644
--- a/arch/tile/include/asm/page.h
+++ b/arch/tile/include/asm/page.h
@@ -20,15 +20,17 @@
 #include <arch/chip.h>
 
 /* PAGE_SHIFT and HPAGE_SHIFT determine the page sizes. */
-#if defined(CONFIG_PAGE_SIZE_16KB)
+#if defined(CONFIG_PAGE_SIZE_4KB)  /* tilepro only */
+#define PAGE_SHIFT	12
+#define CTX_PAGE_FLAG	HV_CTX_PG_SM_4K
+#elif defined(CONFIG_PAGE_SIZE_16KB)
 #define PAGE_SHIFT	14
 #define CTX_PAGE_FLAG	HV_CTX_PG_SM_16K
 #elif defined(CONFIG_PAGE_SIZE_64KB)
 #define PAGE_SHIFT	16
 #define CTX_PAGE_FLAG	HV_CTX_PG_SM_64K
 #else
-#define PAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_SMALL
-#define CTX_PAGE_FLAG	0
+#error Page size not specified in Kconfig
 #endif
 #define HPAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_LARGE
 
-- 
1.9.1