/*************************************************************************/ /*! @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 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)) #ifndef AUTOCONF_INCLUDED #include #endif #endif #include #include #include #include #include "img_defs.h" #include "pvr_debug.h" #include "mutils.h" #if defined(SUPPORT_LINUX_X86_PAT) #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,0)) #define _PAGE_CACHE_WC pgprot_val(cachemode2pgprot(_PAGE_CACHE_MODE_WC)) #endif #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 (boot_cpu_has(X86_FEATURE_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))); #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0)) pat_index = pvr_pat_index(_PAGE_CACHE_MODE_WC); #else pat_index = pvr_pat_index(_PAGE_CACHE_WC); #endif 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) ? #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0)) __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_MASK) | _PAGE_CACHE_MODE_WC) : pgprot_noncached(prot); #else __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_MASK) | _PAGE_CACHE_WC) : pgprot_noncached(prot); #endif } #endif /* defined(SUPPORT_LINUX_X86_PAT) */ IMG_VOID PVRLinuxMUtilsInit(IMG_VOID) { #if defined(SUPPORT_LINUX_X86_PAT) PVRLinuxX86PATProbe(); #endif }