tile: provide CONFIG_PAGE_SIZE_64KB etc for tilepro

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@ezchip.com>
Cc: stable@vger.kernel.org [3.19+]

arch/tile/Kconfig

@@ -176,8 +176,6 @@ 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
@@ -188,8 +186,11 @@ 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"
@@ -199,8 +200,6 @@ config PAGE_SIZE_64KB
 
 endchoice
 
-endif
-
 source "kernel/Kconfig.hz"
 
 config KEXEC

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