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Diffstat (limited to 'pvr-source/services4/srvkm/env/linux/mutils.c')
| -rw-r--r-- | pvr-source/services4/srvkm/env/linux/mutils.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/pvr-source/services4/srvkm/env/linux/mutils.c b/pvr-source/services4/srvkm/env/linux/mutils.c new file mode 100644 index 0000000..8e57476 --- /dev/null +++ b/pvr-source/services4/srvkm/env/linux/mutils.c @@ -0,0 +1,166 @@ +/*************************************************************************/ /*! +@Title Linux memory interface support functions +@Copyright Copyright (c) Imagination Technologies Ltd. All Rights Reserved +@License Dual MIT/GPLv2 + +The contents of this file are subject to the MIT license as set out below. + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +Alternatively, the contents of this file may be used under the terms of +the GNU General Public License Version 2 ("GPL") in which case the provisions +of GPL are applicable instead of those above. + +If you wish to allow use of your version of this file only under the terms of +GPL, and not to allow others to use your version of this file under the terms +of the MIT license, indicate your decision by deleting the provisions above +and replace them with the notice and other provisions required by GPL as set +out in the file called "GPL-COPYING" included in this distribution. If you do +not delete the provisions above, a recipient may use your version of this file +under the terms of either the MIT license or GPL. + +This License is also included in this distribution in the file called +"MIT-COPYING". + +EXCEPT AS OTHERWISE STATED IN A NEGOTIATED AGREEMENT: (A) THE SOFTWARE IS +PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING +BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR +PURPOSE AND NONINFRINGEMENT; AND (B) IN NO EVENT SHALL THE AUTHORS OR +COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER +IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +*/ /**************************************************************************/ + +#include <linux/version.h> + +#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)) +#ifndef AUTOCONF_INCLUDED +#include <linux/config.h> +#endif +#endif + +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <asm/page.h> +#include <asm/pgtable.h> + +#include "img_defs.h" +#include "pvr_debug.h" +#include "mutils.h" + +#if defined(SUPPORT_LINUX_X86_PAT) +#define PAT_LINUX_X86_WC 1 + +#define PAT_X86_ENTRY_BITS 8 + +#define PAT_X86_BIT_PWT 1U +#define PAT_X86_BIT_PCD 2U +#define PAT_X86_BIT_PAT 4U +#define PAT_X86_BIT_MASK (PAT_X86_BIT_PAT | PAT_X86_BIT_PCD | PAT_X86_BIT_PWT) + +static IMG_BOOL g_write_combining_available = IMG_FALSE; + +#define PROT_TO_PAT_INDEX(v, B) ((v & _PAGE_ ## B) ? PAT_X86_BIT_ ## B : 0) + +static inline IMG_UINT +pvr_pat_index(pgprotval_t prot_val) +{ + IMG_UINT ret = 0; + pgprotval_t val = prot_val & _PAGE_CACHE_MASK; + + ret |= PROT_TO_PAT_INDEX(val, PAT); + ret |= PROT_TO_PAT_INDEX(val, PCD); + ret |= PROT_TO_PAT_INDEX(val, PWT); + + return ret; +} + +static inline IMG_UINT +pvr_pat_entry(u64 pat, IMG_UINT index) +{ + return (IMG_UINT)(pat >> (index * PAT_X86_ENTRY_BITS)) & PAT_X86_BIT_MASK; +} + +static IMG_VOID +PVRLinuxX86PATProbe(IMG_VOID) +{ + /* + * cpu_has_pat indicates whether PAT support is available on the CPU, + * but doesn't indicate if it has been enabled. + */ + if (cpu_has_pat) /* PRQA S 3335 */ /* ignore 'no function declared' */ + { + u64 pat; + IMG_UINT pat_index; + IMG_UINT pat_entry; + + PVR_TRACE(("%s: PAT available", __FUNCTION__)); + /* + * There is no Linux API for finding out if write combining + * is avaialable through the PAT, so we take the direct + * approach, and see if the PAT MSR contains a write combining + * entry. + */ + rdmsrl(MSR_IA32_CR_PAT, pat); + PVR_TRACE(("%s: Top 32 bits of PAT: 0x%.8x", __FUNCTION__, (IMG_UINT)(pat >> 32))); + PVR_TRACE(("%s: Bottom 32 bits of PAT: 0x%.8x", __FUNCTION__, (IMG_UINT)(pat))); + + pat_index = pvr_pat_index(_PAGE_CACHE_WC); + PVR_TRACE(("%s: PAT index for write combining: %u", __FUNCTION__, pat_index)); + + pat_entry = pvr_pat_entry(pat, pat_index); + PVR_TRACE(("%s: PAT entry for write combining: 0x%.2x (should be 0x%.2x)", __FUNCTION__, pat_entry, PAT_LINUX_X86_WC)); + +#if defined(SUPPORT_LINUX_X86_WRITECOMBINE) + g_write_combining_available = (IMG_BOOL)(pat_entry == PAT_LINUX_X86_WC); +#endif + } +#if defined(DEBUG) +#if defined(SUPPORT_LINUX_X86_WRITECOMBINE) + if (g_write_combining_available) + { + PVR_TRACE(("%s: Write combining available via PAT", __FUNCTION__)); + } + else + { + PVR_TRACE(("%s: Write combining not available", __FUNCTION__)); + } +#else /* defined(SUPPORT_LINUX_X86_WRITECOMBINE) */ + PVR_TRACE(("%s: Write combining disabled in driver build", __FUNCTION__)); +#endif /* defined(SUPPORT_LINUX_X86_WRITECOMBINE) */ +#endif /* DEBUG */ +} + +pgprot_t +pvr_pgprot_writecombine(pgprot_t prot) +{ + /* + * It would be worth checking from time to time to see if a + * pgprot_writecombine function (or similar) is introduced on Linux for + * x86 processors. If so, this function, and PVRLinuxX86PATProbe can be + * removed, and a macro used to select between pgprot_writecombine and + * pgprot_noncached, dpending on the value for of + * SUPPORT_LINUX_X86_WRITECOMBINE. + */ + /* PRQA S 0481,0482 2 */ /* scalar expressions */ + return (g_write_combining_available) ? + __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_MASK) | _PAGE_CACHE_WC) : pgprot_noncached(prot); +} +#endif /* defined(SUPPORT_LINUX_X86_PAT) */ + +IMG_VOID +PVRLinuxMUtilsInit(IMG_VOID) +{ +#if defined(SUPPORT_LINUX_X86_PAT) + PVRLinuxX86PATProbe(); +#endif +} + |