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authorJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-04-07 22:34:16 +0200
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-04-07 22:34:16 +0200
commit38f4b8c0da01ae7cd9b93386842ce272d6fde9ab (patch)
tree3c8c52201aac038094bfea7efdd0984a8f62045e /arch/powerpc/include/asm/pte-8xx.h
parentMerge branch 'for-linus/xen/core' into for-linus/xen/master (diff)
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jba... (diff)
downloadlinux-38f4b8c0da01ae7cd9b93386842ce272d6fde9ab.tar.xz
linux-38f4b8c0da01ae7cd9b93386842ce272d6fde9ab.zip
Merge commit 'origin/master' into for-linus/xen/master
* commit 'origin/master': (4825 commits) Fix build errors due to CONFIG_BRANCH_TRACER=y parport: Use the PCI IRQ if offered tty: jsm cleanups Adjust path to gpio headers KGDB_SERIAL_CONSOLE check for module Change KCONFIG name tty: Blackin CTS/RTS Change hardware flow control from poll to interrupt driven Add support for the MAX3100 SPI UART. lanana: assign a device name and numbering for MAX3100 serqt: initial clean up pass for tty side tty: Use the generic RS485 ioctl on CRIS tty: Correct inline types for tty_driver_kref_get() splice: fix deadlock in splicing to file nilfs2: support nanosecond timestamp nilfs2: introduce secondary super block nilfs2: simplify handling of active state of segments nilfs2: mark minor flag for checkpoint created by internal operation nilfs2: clean up sketch file nilfs2: super block operations fix endian bug ... Conflicts: arch/x86/include/asm/thread_info.h arch/x86/lguest/boot.c drivers/xen/manage.c
Diffstat (limited to 'arch/powerpc/include/asm/pte-8xx.h')
-rw-r--r--arch/powerpc/include/asm/pte-8xx.h67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h
new file mode 100644
index 000000000000..8c6e31251034
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+++ b/arch/powerpc/include/asm/pte-8xx.h
@@ -0,0 +1,67 @@
+#ifndef _ASM_POWERPC_PTE_8xx_H
+#define _ASM_POWERPC_PTE_8xx_H
+#ifdef __KERNEL__
+
+/*
+ * The PowerPC MPC8xx uses a TLB with hardware assisted, software tablewalk.
+ * We also use the two level tables, but we can put the real bits in them
+ * needed for the TLB and tablewalk. These definitions require Mx_CTR.PPM = 0,
+ * Mx_CTR.PPCS = 0, and MD_CTR.TWAM = 1. The level 2 descriptor has
+ * additional page protection (when Mx_CTR.PPCS = 1) that allows TLB hit
+ * based upon user/super access. The TLB does not have accessed nor write
+ * protect. We assume that if the TLB get loaded with an entry it is
+ * accessed, and overload the changed bit for write protect. We use
+ * two bits in the software pte that are supposed to be set to zero in
+ * the TLB entry (24 and 25) for these indicators. Although the level 1
+ * descriptor contains the guarded and writethrough/copyback bits, we can
+ * set these at the page level since they get copied from the Mx_TWC
+ * register when the TLB entry is loaded. We will use bit 27 for guard, since
+ * that is where it exists in the MD_TWC, and bit 26 for writethrough.
+ * These will get masked from the level 2 descriptor at TLB load time, and
+ * copied to the MD_TWC before it gets loaded.
+ * Large page sizes added. We currently support two sizes, 4K and 8M.
+ * This also allows a TLB hander optimization because we can directly
+ * load the PMD into MD_TWC. The 8M pages are only used for kernel
+ * mapping of well known areas. The PMD (PGD) entries contain control
+ * flags in addition to the address, so care must be taken that the
+ * software no longer assumes these are only pointers.
+ */
+
+/* Definitions for 8xx embedded chips. */
+#define _PAGE_PRESENT 0x0001 /* Page is valid */
+#define _PAGE_FILE 0x0002 /* when !present: nonlinear file mapping */
+#define _PAGE_NO_CACHE 0x0002 /* I: cache inhibit */
+#define _PAGE_SHARED 0x0004 /* No ASID (context) compare */
+
+/* These five software bits must be masked out when the entry is loaded
+ * into the TLB.
+ */
+#define _PAGE_EXEC 0x0008 /* software: i-cache coherency required */
+#define _PAGE_GUARDED 0x0010 /* software: guarded access */
+#define _PAGE_DIRTY 0x0020 /* software: page changed */
+#define _PAGE_RW 0x0040 /* software: user write access allowed */
+#define _PAGE_ACCESSED 0x0080 /* software: page referenced */
+
+/* Setting any bits in the nibble with the follow two controls will
+ * require a TLB exception handler change. It is assumed unused bits
+ * are always zero.
+ */
+#define _PAGE_HWWRITE 0x0100 /* h/w write enable: never set in Linux PTE */
+#define _PAGE_USER 0x0800 /* One of the PP bits, the other is USER&~RW */
+
+#define _PMD_PRESENT 0x0001
+#define _PMD_BAD 0x0ff0
+#define _PMD_PAGE_MASK 0x000c
+#define _PMD_PAGE_8M 0x000c
+
+#define _PTE_NONE_MASK _PAGE_ACCESSED
+
+/* Until my rework is finished, 8xx still needs atomic PTE updates */
+#define PTE_ATOMIC_UPDATES 1
+
+/* We need to add _PAGE_SHARED to kernel pages */
+#define _PAGE_KERNEL_RO (_PAGE_SHARED)
+#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_PTE_8xx_H */