/************************************************************************** * * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., 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 Hellström <thomas-at-tungstengraphics-dot-com> */ #include <linux/dma-buf-map.h>#include <linux/export.h>#include <linux/highmem.h>#include <linux/cc_platform.h>#include <xen/xen.h> #include <drm/drm_cache.h> /* A small bounce buffer that fits on the stack. */#define MEMCPY_BOUNCE_SIZE 128 #if defined(CONFIG_X86)#include <asm/smp.h> /* * clflushopt is an unordered instruction which needs fencing with mfence or * sfence to avoid ordering issues.  For drm_clflush_page this fencing happens * in the caller. */static voiddrm_clflush_page(struct page *page){	uint8_t *page_virtual;	unsigned int i;	const int size = boot_cpu_data.x86_clflush_size; 	if (unlikely(page == NULL))		return; 	page_virtual = kmap_atomic(page);	for (i = 0; i < PAGE_SIZE; i += size)		clflushopt(page_virtual + i);	kunmap_atomic(page_virtual);} static void drm_cache_flush_clflush(struct page *pages[],				    unsigned long num_pages){	unsigned long i; 	mb(); /*Full memory barrier used before so that CLFLUSH is ordered*/	for (i = 0; i < num_pages; i++)		drm_clflush_page(*pages++);	mb(); /*Also used after CLFLUSH so that all cache is flushed*/}#endif /** * drm_clflush_pages - Flush dcache lines of a set of pages. * @pages: List of pages to be flushed. * @num_pages: Number of pages in the array. * * Flush every data cache line entry that points to an address belonging * to a page in the array. */voiddrm_clflush_pages(struct page *pages[], unsigned long num_pages){ #if defined(CONFIG_X86)	if (static_cpu_has(X86_FEATURE_CLFLUSH)) {		drm_cache_flush_clflush(pages, num_pages);		return;	} 	if (wbinvd_on_all_cpus())		pr_err("Timed out waiting for cache flush\n"); #elif defined(__powerpc__)	unsigned long i; 	for (i = 0; i < num_pages; i++) {		struct page *page = pages[i];		void *page_virtual; 		if (unlikely(page == NULL))			continue; 		page_virtual = kmap_atomic(page);		flush_dcache_range((unsigned long)page_virtual,				   (unsigned long)page_virtual + PAGE_SIZE);		kunmap_atomic(page_virtual);	}#else	pr_err("Architecture has no drm_cache.c support\n");	WARN_ON_ONCE(1);#endif}EXPORT_SYMBOL(drm_clflush_pages); /** * drm_clflush_sg - Flush dcache lines pointing to a scather-gather. * @st: struct sg_table. * * Flush every data cache line entry that points to an address in the * sg. */voiddrm_clflush_sg(struct sg_table *st){#if defined(CONFIG_X86)	if (static_cpu_has(X86_FEATURE_CLFLUSH)) {		struct sg_page_iter sg_iter; 		mb(); /*CLFLUSH is ordered only by using memory barriers*/		for_each_sgtable_page(st, &sg_iter, 0)			drm_clflush_page(sg_page_iter_page(&sg_iter));		mb(); /*Make sure that all cache line entry is flushed*/ 		return;	} 	if (wbinvd_on_all_cpus())		pr_err("Timed out waiting for cache flush\n");#else	pr_err("Architecture has no drm_cache.c support\n");	WARN_ON_ONCE(1);#endif}EXPORT_SYMBOL(drm_clflush_sg); /** * drm_clflush_virt_range - Flush dcache lines of a region * @addr: Initial kernel memory address. * @length: Region size. * * Flush every data cache line entry that points to an address in the * region requested. */voiddrm_clflush_virt_range(void *addr, unsigned long length){#if defined(CONFIG_X86)	if (static_cpu_has(X86_FEATURE_CLFLUSH)) {		const int size = boot_cpu_data.x86_clflush_size;		void *end = addr + length; 		addr = (void *)(((unsigned long)addr) & -size);		mb(); /*CLFLUSH is only ordered with a full memory barrier*/		for (; addr < end; addr += size)			clflushopt(addr);		clflushopt(end - 1); /* force serialisation */		mb(); /*Ensure that every data cache line entry is flushed*/		return;	} 	if (wbinvd_on_all_cpus())		pr_err("Timed out waiting for cache flush\n");#else	pr_err("Architecture has no drm_cache.c support\n");	WARN_ON_ONCE(1);#endif}EXPORT_SYMBOL(drm_clflush_virt_range); bool drm_need_swiotlb(int dma_bits){	struct resource *tmp;	resource_size_t max_iomem = 0; 	/*	 * Xen paravirtual hosts require swiotlb regardless of requested dma	 * transfer size.	 *	 * NOTE: Really, what it requires is use of the dma_alloc_coherent	 *       allocator used in ttm_dma_populate() instead of	 *       ttm_populate_and_map_pages(), which bounce buffers so much in	 *       Xen it leads to swiotlb buffer exhaustion.	 */	if (xen_pv_domain())		return true; 	/*	 * Enforce dma_alloc_coherent when memory encryption is active as well	 * for the same reasons as for Xen paravirtual hosts.	 */	if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))		return true; 	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling)		max_iomem = max(max_iomem,  tmp->end); 	return max_iomem > ((u64)1 << dma_bits);}EXPORT_SYMBOL(drm_need_swiotlb); static void memcpy_fallback(struct dma_buf_map *dst,			    const struct dma_buf_map *src,			    unsigned long len){	if (!dst->is_iomem && !src->is_iomem) {		memcpy(dst->vaddr, src->vaddr, len);	} else if (!src->is_iomem) {		dma_buf_map_memcpy_to(dst, src->vaddr, len);	} else if (!dst->is_iomem) {		memcpy_fromio(dst->vaddr, src->vaddr_iomem, len);	} else {		/*		 * Bounce size is not performance tuned, but using a		 * bounce buffer like this is significantly faster than		 * resorting to ioreadxx() + iowritexx().		 */		char bounce[MEMCPY_BOUNCE_SIZE];		void __iomem *_src = src->vaddr_iomem;		void __iomem *_dst = dst->vaddr_iomem; 		while (len >= MEMCPY_BOUNCE_SIZE) {			memcpy_fromio(bounce, _src, MEMCPY_BOUNCE_SIZE);			memcpy_toio(_dst, bounce, MEMCPY_BOUNCE_SIZE);			_src += MEMCPY_BOUNCE_SIZE;			_dst += MEMCPY_BOUNCE_SIZE;			len -= MEMCPY_BOUNCE_SIZE;		}		if (len) {			memcpy_fromio(bounce, _src, MEMCPY_BOUNCE_SIZE);			memcpy_toio(_dst, bounce, MEMCPY_BOUNCE_SIZE);		}	}} #ifdef CONFIG_X86 static DEFINE_STATIC_KEY_FALSE(has_movntdqa); static void __memcpy_ntdqa(void *dst, const void *src, unsigned long len){	kernel_fpu_begin(); 	while (len >= 4) {		asm("movntdqa	(%0), %%xmm0\n"		    "movntdqa 16(%0), %%xmm1\n"		    "movntdqa 32(%0), %%xmm2\n"		    "movntdqa 48(%0), %%xmm3\n"		    "movaps %%xmm0,   (%1)\n"		    "movaps %%xmm1, 16(%1)\n"		    "movaps %%xmm2, 32(%1)\n"		    "movaps %%xmm3, 48(%1)\n"		    :: "r" (src), "r" (dst) : "memory");		src += 64;		dst += 64;		len -= 4;	}	while (len--) {		asm("movntdqa (%0), %%xmm0\n"		    "movaps %%xmm0, (%1)\n"		    :: "r" (src), "r" (dst) : "memory");		src += 16;		dst += 16;	} 	kernel_fpu_end();} /* * __drm_memcpy_from_wc copies @len bytes from @src to @dst using * non-temporal instructions where available. Note that all arguments * (@src, @dst) must be aligned to 16 bytes and @len must be a multiple * of 16. */static void __drm_memcpy_from_wc(void *dst, const void *src, unsigned long len){	if (unlikely(((unsigned long)dst | (unsigned long)src | len) & 15))		memcpy(dst, src, len);	else if (likely(len))		__memcpy_ntdqa(dst, src, len >> 4);} /** * drm_memcpy_from_wc - Perform the fastest available memcpy from a source * that may be WC. * @dst: The destination pointer * @src: The source pointer * @len: The size of the area o transfer in bytes * * Tries an arch optimized memcpy for prefetching reading out of a WC region, * and if no such beast is available, falls back to a normal memcpy. */void drm_memcpy_from_wc(struct dma_buf_map *dst,			const struct dma_buf_map *src,			unsigned long len){	if (WARN_ON(in_interrupt())) {		memcpy_fallback(dst, src, len);		return;	} 	if (static_branch_likely(&has_movntdqa)) {		__drm_memcpy_from_wc(dst->is_iomem ?				     (void __force *)dst->vaddr_iomem :				     dst->vaddr,				     src->is_iomem ?				     (void const __force *)src->vaddr_iomem :				     src->vaddr,				     len);		return;	} 	memcpy_fallback(dst, src, len);}EXPORT_SYMBOL(drm_memcpy_from_wc); /* * drm_memcpy_init_early - One time initialization of the WC memcpy code */void drm_memcpy_init_early(void){	/*	 * Some hypervisors (e.g. KVM) don't support VEX-prefix instructions	 * emulation. So don't enable movntdqa in hypervisor guest.	 */	if (static_cpu_has(X86_FEATURE_XMM4_1) &&	    !boot_cpu_has(X86_FEATURE_HYPERVISOR))		static_branch_enable(&has_movntdqa);}#elsevoid drm_memcpy_from_wc(struct dma_buf_map *dst,			const struct dma_buf_map *src,			unsigned long len){	WARN_ON(in_interrupt()); 	memcpy_fallback(dst, src, len);}EXPORT_SYMBOL(drm_memcpy_from_wc); void drm_memcpy_init_early(void){}#endif /* CONFIG_X86 */