Merge tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag

Pull new ImgTec Meta architecture from James Hogan:
 "This adds core architecture support for Imagination's Meta processor
  cores, followed by some later miscellaneous arch/metag cleanups and
  fixes which I kept separate to ease review:

   - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
   - A few fixes all over, particularly for symbol prefixes
   - A few privilege protection fixes
   - Several cleanups (setup.c includes, split out a lot of
     metag_ksyms.c)
   - Fix some missing exports
   - Convert hugetlb to use vm_unmapped_area()
   - Copy device tree to non-init memory
   - Provide dma_get_sgtable()"

* tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits)
  metag: Provide dma_get_sgtable()
  metag: prom.h: remove declaration of metag_dt_memblock_reserve()
  metag: copy devicetree to non-init memory
  metag: cleanup metag_ksyms.c includes
  metag: move mm/init.c exports out of metag_ksyms.c
  metag: move usercopy.c exports out of metag_ksyms.c
  metag: move setup.c exports out of metag_ksyms.c
  metag: move kick.c exports out of metag_ksyms.c
  metag: move traps.c exports out of metag_ksyms.c
  metag: move irq enable out of irqflags.h on SMP
  genksyms: fix metag symbol prefix on crc symbols
  metag: hugetlb: convert to vm_unmapped_area()
  metag: export clear_page and copy_page
  metag: export metag_code_cache_flush_all
  metag: protect more non-MMU memory regions
  metag: make TXPRIVEXT bits explicit
  metag: kernel/setup.c: sort includes
  perf: Enable building perf tools for Meta
  metag: add boot time LNKGET/LNKSET check
  metag: add __init to metag_cache_probe()
  ...

1 files changed, 97 insertions, 0 deletions

diff --git a/arch/metag/kernel/user_gateway.S b/arch/metag/kernel/user_gateway.S
new file mode 100644
index 000000000000..7167f3e8db6b
--- /dev/null
+++ b/arch/metag/kernel/user_gateway.S
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2010 Imagination Technologies Ltd.
+ *
+ * This file contains code that can be accessed from userspace and can
+ * access certain kernel data structures without the overhead of a system
+ * call.
+ */
+
+#include <asm/metag_regs.h>
+#include <asm/user_gateway.h>
+
+/*
+ * User helpers.
+ *
+ * These are segment of kernel provided user code reachable from user space
+ * at a fixed address in kernel memory.  This is used to provide user space
+ * with some operations which require kernel help because of unimplemented
+ * native feature and/or instructions in some Meta CPUs. The idea is for
+ * this code to be executed directly in user mode for best efficiency but
+ * which is too intimate with the kernel counter part to be left to user
+ * libraries.  The kernel reserves the right to change this code as needed
+ * without warning. Only the entry points and their results are guaranteed
+ * to be stable.
+ *
+ * Each segment is 64-byte aligned.  This mechanism should be used only for
+ * for things that are really small and justified, and not be abused freely.
+ */
+	.text
+	.global	___user_gateway_start
+___user_gateway_start:
+
+	/* get_tls
+	 * Offset:	 0
+	 * Description:	 Get the TLS pointer for this process.
+	 */
+	.global	___kuser_get_tls
+	.type	___kuser_get_tls,function
+___kuser_get_tls:
+	MOVT	D1Ar1,#HI(USER_GATEWAY_PAGE + USER_GATEWAY_TLS)
+	ADD	D1Ar1,D1Ar1,#LO(USER_GATEWAY_PAGE + USER_GATEWAY_TLS)
+	MOV	D1Ar3,TXENABLE
+	AND	D1Ar3,D1Ar3,#(TXENABLE_THREAD_BITS)
+	LSR	D1Ar3,D1Ar3,#(TXENABLE_THREAD_S - 2)
+	GETD	D0Re0,[D1Ar1+D1Ar3]
+___kuser_get_tls_end:		/* Beyond this point the read will complete */
+	MOV	PC,D1RtP
+	.size	___kuser_get_tls,.-___kuser_get_tls
+	.global	___kuser_get_tls_end
+
+	/* cmpxchg
+	 * Offset:	 64
+	 * Description:  Replace the value at 'ptr' with 'newval' if the current
+	 *		 value is 'oldval'. Return zero if we succeeded,
+	 *		 non-zero otherwise.
+	 *
+	 * Reference prototype:
+	 *
+	 *	int __kuser_cmpxchg(int oldval, int newval, unsigned long *ptr)
+	 *
+	 */
+	.balign 64
+	.global ___kuser_cmpxchg
+	.type   ___kuser_cmpxchg,function
+___kuser_cmpxchg:
+#ifdef CONFIG_SMP
+	/*
+	 * We must use LNKGET/LNKSET with an SMP kernel because the other method
+	 * does not provide atomicity across multiple CPUs.
+	 */
+0:	LNKGETD	D0Re0,[D1Ar3]
+	CMP	D0Re0,D1Ar1
+	LNKSETDZ [D1Ar3],D0Ar2
+	BNZ	1f
+	DEFR	D0Re0,TXSTAT
+	ANDT	D0Re0,D0Re0,#HI(0x3f000000)
+	CMPT	D0Re0,#HI(0x02000000)
+	BNE	0b
+#ifdef CONFIG_METAG_LNKGET_AROUND_CACHE
+	DCACHE  [D1Ar3], D0Re0
+#endif
+1:	MOV	D0Re0,#1
+	XORZ	D0Re0,D0Re0,D0Re0
+	MOV	PC,D1RtP
+#else
+	GETD	D0Re0,[D1Ar3]
+	CMP	D0Re0,D1Ar1
+	SETDZ	[D1Ar3],D0Ar2
+___kuser_cmpxchg_end:		/* Beyond this point the write will complete */
+	MOV	D0Re0,#1
+	XORZ	D0Re0,D0Re0,D0Re0
+	MOV	PC,D1RtP
+#endif /* CONFIG_SMP */
+	.size	___kuser_cmpxchg,.-___kuser_cmpxchg
+	.global	___kuser_cmpxchg_end
+
+	.global	___user_gateway_end
+___user_gateway_end: