diff options
Diffstat (limited to 'drivers/staging/psb/ttm/ttm_pat_compat.c')
| -rw-r--r-- | drivers/staging/psb/ttm/ttm_pat_compat.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/staging/psb/ttm/ttm_pat_compat.c b/drivers/staging/psb/ttm/ttm_pat_compat.c new file mode 100644 index 000000000000..d9a13bb249ca --- /dev/null +++ b/drivers/staging/psb/ttm/ttm_pat_compat.c @@ -0,0 +1,178 @@ +/************************************************************************** + * + * Copyright (c) 2007-2008 Tungsten Graphics, Inc., Cedar Park, TX., USA + * All Rights Reserved. + * Copyright (c) 2009 VMware, Inc., Palo Alto, CA., USA + * All Rights Reserved. + * + * 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, sub license, 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 (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + * 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 NON-INFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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. + * + **************************************************************************/ +/* + * Authors: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com> + */ + +#include "ttm_pat_compat.h" +#include <linux/version.h> + +#include <linux/spinlock.h> +#include <asm/pgtable.h> + +#if (defined(CONFIG_X86) && !defined(CONFIG_X86_PAT)) +#include <asm/tlbflush.h> +#include <asm/msr.h> +#include <asm/system.h> +#include <linux/notifier.h> +#include <linux/cpu.h> + +#ifndef MSR_IA32_CR_PAT +#define MSR_IA32_CR_PAT 0x0277 +#endif + +#ifndef _PAGE_PAT +#define _PAGE_PAT 0x080 +#endif + +static int ttm_has_pat = 0; + +/* + * Used at resume-time when CPU-s are fired up. + */ + +static void ttm_pat_ipi_handler(void *notused) +{ + u32 v1, v2; + + rdmsr(MSR_IA32_CR_PAT, v1, v2); + v2 &= 0xFFFFFFF8; + v2 |= 0x00000001; + wbinvd(); + wrmsr(MSR_IA32_CR_PAT, v1, v2); + wbinvd(); + __flush_tlb_all(); +} + +static void ttm_pat_enable(void) +{ +#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,27)) + if (on_each_cpu(ttm_pat_ipi_handler, NULL, 1, 1) != 0) { +#else + if (on_each_cpu(ttm_pat_ipi_handler, NULL, 1) != 0) { +#endif + printk(KERN_ERR "Timed out setting up CPU PAT.\n"); + } +} + +void ttm_pat_resume(void) +{ + if (unlikely(!ttm_has_pat)) + return; + + ttm_pat_enable(); +} + +static int psb_cpu_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + if (action == CPU_ONLINE) { + ttm_pat_resume(); + } + + return 0; +} + +static struct notifier_block psb_nb = { + .notifier_call = psb_cpu_callback, + .priority = 1 +}; + +/* + * Set i386 PAT entry PAT4 to Write-combining memory type on all processors. + */ + +void ttm_pat_init(void) +{ + if (likely(ttm_has_pat)) + return; + + if (!boot_cpu_has(X86_FEATURE_PAT)) { + return; + } + + ttm_pat_enable(); + + if (num_present_cpus() > 1) + register_cpu_notifier(&psb_nb); + + ttm_has_pat = 1; +} + +void ttm_pat_takedown(void) +{ + if (unlikely(!ttm_has_pat)) + return; + + if (num_present_cpus() > 1) + unregister_cpu_notifier(&psb_nb); + + ttm_has_pat = 0; +} + +pgprot_t pgprot_ttm_x86_wc(pgprot_t prot) +{ + if (likely(ttm_has_pat)) { + pgprot_val(prot) |= _PAGE_PAT; + return prot; + } else { + return pgprot_noncached(prot); + } +} + +#else + +void ttm_pat_init(void) +{ +} + +void ttm_pat_takedown(void) +{ +} + +void ttm_pat_resume(void) +{ +} + +#ifdef CONFIG_X86 +#include <asm/pat.h> + +pgprot_t pgprot_ttm_x86_wc(pgprot_t prot) +{ + uint32_t cache_bits = ((1) ? _PAGE_CACHE_WC : _PAGE_CACHE_UC_MINUS); + + return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_MASK) | cache_bits); +} +#else +pgprot_t pgprot_ttm_x86_wc(pgprot_t prot) +{ + BUG(); +} +#endif +#endif |