ppc64 iommu rewrite part 5/5

Implement support for Apple DART IOMMU (PowerMac G5)

This allows to use more than 2Gb of RAM on a PowerMac G5. You can also boot with iommu=off to disable it, but then you get back the 2Gb RAM limitation.

Ben.

# This is a BitKeeper generated diff -Nru style patch. #
# ChangeSet
# 2004/02/27 22:37:07+11:00 [email protected]
# PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me
#

# include/asm-ppc64/cacheflush.h
#   2004/02/27 22:36:53+11:00 [email protected] +3 -0
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/mm/hash_utils.c
#   2004/02/27 22:36:53+11:00 [email protected] +23 -0
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/kernel/prom.c
#   2004/02/27 22:36:53+11:00 [email protected] +56 -2
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/kernel/pmac_pci.c
#   2004/02/27 22:36:53+11:00 [email protected] +6 -0
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/kernel/misc.S
#   2004/02/27 22:36:53+11:00 [email protected] +42 -0
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/kernel/Makefile
#   2004/02/27 22:36:53+11:00 [email protected] +2 -0
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/Kconfig
#   2004/02/27 22:36:53+11:00 [email protected] +11 -0
#   PowerMac G5 DART (iommu) support, by Olof Johansson with some hacks from me 
# 
# arch/ppc64/kernel/pmac_iommu.c
#   2004/02/27 22:30:15+11:00 [email protected] +301 -0
# 
# arch/ppc64/kernel/pmac_iommu.c
#   2004/02/27 22:30:15+11:00 [email protected] +0 -0
#   BitKeeper file /home/benh/kernels/linux-iommu/arch/ppc64/kernel/pmac_iommu.c
# 
diff -Nru a/arch/ppc64/Kconfig b/arch/ppc64/Kconfig
--- a/arch/ppc64/Kconfig	Fri Feb 27 22:44:57 2004
+++ b/arch/ppc64/Kconfig	Fri Feb 27 22:44:57 2004
@@ -89,6 +89,17 @@
 	bool "Apple PowerMac G5 support"
 	select ADB_PMU

+config PMAC_DART
+ bool "Enable DART/IOMMU on PowerMac (allow >2G of RAM)"
+ depends on PPC_PMAC
+ depends on EXPERIMENTAL
+ default n
+ help

+	  Enabling DART makes it possible to boot a PowerMac G5 with more
+	  than 2GB of memory. Note that the code is very new and untested
+	  at this time, so it has to be considered experimental. Enabling
+	  this might result in data loss.

+
config PPC_PMAC64
bool
depends on PPC_PMAC

diff -Nru a/arch/ppc64/kernel/Makefile b/arch/ppc64/kernel/Makefile
@@ -50,6 +50,8 @@
 obj-$(CONFIG_PPC_PMAC)		+= pmac_setup.o pmac_feature.o pmac_pci.o \
 				   pmac_time.o pmac_nvram.o pmac_low_i2c.o \
 				   open_pic_u3.o
+obj-$(CONFIG_PMAC_DART)		+= pmac_iommu.o
+
 ifdef CONFIG_SMP
 obj-$(CONFIG_PPC_PMAC)		+= pmac_smp.o smp-tbsync.o
 endif

diff -Nru a/arch/ppc64/kernel/pmac_pci.c b/arch/ppc64/kernel/pmac_pci.c
@@ -26,6 +26,7 @@
 #include <asm/pci-bridge.h>
 #include <asm/machdep.h>
 #include <asm/pmac_feature.h>
+#include <asm/iommu.h>
 
 #include "pci.h"
 #include "pmac.h"

@@ -655,6 +656,11 @@
 		pci_read_irq_line(dev);
 
 	pci_fix_bus_sysdata();
+
+#ifdef CONFIG_PMAC_DART
+	iommu_setup_pmac();
+#endif /* CONFIG_PMAC_DART */
+
 }
 
 static void __init pmac_fixup_phb_resources(void)

diff -Nru a/arch/ppc64/mm/hash_utils.c b/arch/ppc64/mm/hash_utils.c
@@ -61,6 +61,10 @@
  *
  */
 
+#ifdef CONFIG_PMAC_DART
+extern unsigned long dart_tablebase;
+#endif /* CONFIG_PMAC_DART */
+
 HTAB htab_data = {NULL, 0, 0, 0, 0};
 
 extern unsigned long _SDR1;

@@ -180,6 +184,25 @@
 		base = lmb.memory.region[i].physbase + KERNELBASE;
 		size = lmb.memory.region[i].size;
 
+#ifdef CONFIG_PMAC_DART
+		/* Do not map the DART space. Fortunately, it will be aligned
+		 * in such a way that it will not cross two lmb regions and will
+		 * fit within a single 16Mb page.
+		 * The DART space is assumed to be a full 16Mb region even if we
+		 * only use 2Mb of that space. We will use more of it later for
+		 * AGP GART. We have to use a full 16Mb large page.
+		 */
+		if (dart_tablebase != 0 && dart_tablebase >= base
+		    && dart_tablebase < (base + size)) {
+			if (base != dart_tablebase)
+				create_pte_mapping(base, dart_tablebase, mode_rw,
+						   use_largepages);
+			if ((base + size) > (dart_tablebase + 16*MB))
+				create_pte_mapping(dart_tablebase + 16*MB, base + size,
+						   mode_rw, use_largepages);
+			continue;
+		}
+#endif /* CONFIG_PMAC_DART */
 		create_pte_mapping(base, base + size, mode_rw, use_largepages);
 	}
 }

diff -Nru a/include/asm-ppc64/cacheflush.h b/include/asm-ppc64/cacheflush.h
@@ -23,6 +23,9 @@
 				    struct page *page, unsigned long addr,
 				    int len);
 
+extern void flush_dcache_range(unsigned long start, unsigned long stop);
+extern void flush_dcache_phys_range(unsigned long start, unsigned long stop);
+
 #define copy_to_user_page(vma, page, vaddr, dst, src, len) \
 do { memcpy(dst, src, len); \
      flush_icache_user_range(vma, page, vaddr, len); \