diff options
| author | Max Filippov <jcmvbkbc@gmail.com> | 2012-11-19 07:00:41 +0400 |
|---|---|---|
| committer | Chris Zankel <chris@zankel.net> | 2012-12-18 21:10:22 -0800 |
| commit | c622b29d1f38021411965b7e0170ab055551b257 (patch) | |
| tree | f86875612ade331965b80abafb14cbd796924461 /arch | |
| parent | 733536b865441d9bad02c4711a4372d48ce21e54 (diff) | |
| download | linux-c622b29d1f38021411965b7e0170ab055551b257.tar.bz2 | |
xtensa: initialize atomctl SR
In order to use S32C1I instruction on cores with ATOMCTL SR the register
must be properly initialized.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/xtensa/include/asm/initialize_mmu.h | 55 | ||||
| -rw-r--r-- | arch/xtensa/kernel/head.S | 3 |
2 files changed, 58 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/initialize_mmu.h b/arch/xtensa/include/asm/initialize_mmu.h new file mode 100644 index 000000000000..e1f8ba4061ed --- /dev/null +++ b/arch/xtensa/include/asm/initialize_mmu.h @@ -0,0 +1,55 @@ +/* + * arch/xtensa/include/asm/initialize_mmu.h + * + * Initializes MMU: + * + * For the new V3 MMU we remap the TLB from virtual == physical + * to the standard Linux mapping used in earlier MMU's. + * + * The the MMU we also support a new configuration register that + * specifies how the S32C1I instruction operates with the cache + * controller. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of + * this archive for more details. + * + * Copyright (C) 2008 - 2012 Tensilica, Inc. + * + * Marc Gauthier <marc@tensilica.com> + * Pete Delaney <piet@tensilica.com> + */ + +#ifndef _XTENSA_INITIALIZE_MMU_H +#define _XTENSA_INITIALIZE_MMU_H + +#ifdef __ASSEMBLY__ + +#define XTENSA_HWVERSION_RC_2009_0 230000 + + .macro initialize_mmu + +#if XCHAL_HAVE_S32C1I && (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0) +/* + * We Have Atomic Operation Control (ATOMCTL) Register; Initialize it. + * For details see Documentation/xtensa/atomctl.txt + */ +#if XCHAL_DCACHE_IS_COHERENT + movi a3, 0x25 /* For SMP/MX -- internal for writeback, + * RCW otherwise + */ +#else + movi a3, 0x29 /* non-MX -- Most cores use Std Memory + * Controlers which usually can't use RCW + */ +#endif + wsr a3, atomctl +#endif /* XCHAL_HAVE_S32C1I && + * (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0) + */ + + .endm + +#endif /*__ASSEMBLY__*/ + +#endif /* _XTENSA_INITIALIZE_MMU_H */ diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S index 417998c02108..9013ae0174f8 100644 --- a/arch/xtensa/kernel/head.S +++ b/arch/xtensa/kernel/head.S @@ -18,6 +18,7 @@ #include <asm/processor.h> #include <asm/page.h> #include <asm/cacheasm.h> +#include <asm/initialize_mmu.h> #include <linux/init.h> #include <linux/linkage.h> @@ -155,6 +156,8 @@ ENTRY(_startup) isync + initialize_mmu + /* Unpack data sections * * The linker script used to build the Linux kernel image |