diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_memcpy.c')
-rw-r--r-- | drivers/gpu/drm/i915/i915_memcpy.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_memcpy.c b/drivers/gpu/drm/i915/i915_memcpy.c new file mode 100644 index 000000000000..6f1df0ec8a81 --- /dev/null +++ b/drivers/gpu/drm/i915/i915_memcpy.c @@ -0,0 +1,101 @@ +/* + * Copyright © 2016 Intel Corporation + * + * 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 (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 NONINFRINGEMENT. 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/kernel.h> +#include <asm/fpu/api.h> + +#include "i915_drv.h" + +DEFINE_STATIC_KEY_FALSE(has_movntdqa); + +#ifdef CONFIG_AS_MOVNTDQA +static void __memcpy_ntdqa(void *dst, const void *src, unsigned long len) +{ + kernel_fpu_begin(); + + len >>= 4; + 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(); +} +#endif + +/** + * i915_memcpy_from_wc: perform an accelerated *aligned* read from WC + * @dst: destination pointer + * @src: source pointer + * @len: how many bytes to copy + * + * i915_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. + * + * To test whether accelerated reads from WC are supported, use + * i915_memcpy_from_wc(NULL, NULL, 0); + * + * Returns true if the copy was successful, false if the preconditions + * are not met. + */ +bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len) +{ + if (unlikely(((unsigned long)dst | (unsigned long)src | len) & 15)) + return false; + +#ifdef CONFIG_AS_MOVNTDQA + if (static_branch_likely(&has_movntdqa)) { + if (likely(len)) + __memcpy_ntdqa(dst, src, len); + return true; + } +#endif + + return false; +} + +void i915_memcpy_init_early(struct drm_i915_private *dev_priv) +{ + if (static_cpu_has(X86_FEATURE_XMM4_1)) + static_branch_enable(&has_movntdqa); +} |