[PATCH] powerpc: generalize PPC44x_PIN_SIZE

The following patch generalizes PPC44x_PIN_SIZE by changing it to
PPC_PIN_SIZE, which can be defined by any sub-arch to automatically adjust
VMALLOC_START.

Define PPC_PIN_SIZE on 8xx, avoiding potential conflicts with the
pinned space.
Signed-off-by: NMarcelo Tosatti <marcelo.tosatti@cyclades.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/ppc/mm/44x_mmu.c

@@ -104,7 +104,7 @@ unsigned long __init mmu_mapin_ram(void)
 
 	/* Determine number of entries necessary to cover lowmem */
 	pinned_tlbs = (unsigned int)
-		(_ALIGN(total_lowmem, PPC44x_PIN_SIZE) >> PPC44x_PIN_SHIFT);
+		(_ALIGN(total_lowmem, PPC_PIN_SIZE) >> PPC44x_PIN_SHIFT);
 
 	/* Write upper watermark to save location */
 	tlb_44x_hwater = PPC44x_LOW_SLOT - pinned_tlbs;
@@ -112,7 +112,7 @@ unsigned long __init mmu_mapin_ram(void)
 	/* If necessary, set additional pinned TLBs */
 	if (pinned_tlbs > 1)
 		for (i = (PPC44x_LOW_SLOT-(pinned_tlbs-1)); i < PPC44x_LOW_SLOT; i++) {
-			unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC44x_PIN_SIZE;
+			unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC_PIN_SIZE;
 			ppc44x_pin_tlb(i, phys_addr+PAGE_OFFSET, phys_addr);
 		}
 

include/asm-ppc/ibm44x.h

@@ -29,7 +29,7 @@
 
 /* TLB entry offset/size used for pinning kernel lowmem */
 #define PPC44x_PIN_SHIFT	28
-#define PPC44x_PIN_SIZE		(1 << PPC44x_PIN_SHIFT)
+#define PPC_PIN_SIZE		(1 << PPC44x_PIN_SHIFT)
 
 /* Lowest TLB slot consumed by the default pinned TLBs */
 #define PPC44x_LOW_SLOT		63

include/asm-ppc/mpc8xx.h

@@ -113,6 +113,8 @@ enum ppc_sys_devices {
 	MPC8xx_CPM_USB,
 };
 
+#define PPC_PIN_SIZE	(24 * 1024 * 1024)	/* 24Mbytes of data pinned */
+
 #ifndef BOARD_CHIP_NAME
 #define BOARD_CHIP_NAME ""
 #endif

include/asm-ppc/pgtable.h

@@ -12,6 +12,7 @@
 #include <asm/processor.h>		/* For TASK_SIZE */
 #include <asm/mmu.h>
 #include <asm/page.h>
+#include <asm/io.h>			/* For sub-arch specific PPC_PIN_SIZE */
 struct mm_struct;
 
 extern unsigned long va_to_phys(unsigned long address);
@@ -127,9 +128,8 @@ extern unsigned long ioremap_bot, ioremap_base;
  * of RAM.  -- Cort
  */
 #define VMALLOC_OFFSET (0x1000000) /* 16M */
-#ifdef CONFIG_44x
-#include <asm/ibm44x.h>
-#define VMALLOC_START (((_ALIGN((long)high_memory, PPC44x_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
+#ifdef PPC_PIN_SIZE
+#define VMALLOC_START (((_ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
 #else
 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
 #endif