diff options
Diffstat (limited to 'arch/s390/lib/crc32-glue.c')
| -rw-r--r-- | arch/s390/lib/crc32-glue.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/s390/lib/crc32-glue.c b/arch/s390/lib/crc32-glue.c new file mode 100644 index 000000000000..137080e61f90 --- /dev/null +++ b/arch/s390/lib/crc32-glue.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CRC-32 implemented with the z/Architecture Vector Extension Facility. + * + * Copyright IBM Corp. 2015 + * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> + */ +#define KMSG_COMPONENT "crc32-vx" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/module.h> +#include <linux/cpufeature.h> +#include <linux/crc32.h> +#include <asm/fpu.h> +#include "crc32-vx.h" + +#define VX_MIN_LEN 64 +#define VX_ALIGNMENT 16L +#define VX_ALIGN_MASK (VX_ALIGNMENT - 1) + +static DEFINE_STATIC_KEY_FALSE(have_vxrs); + +/* + * DEFINE_CRC32_VX() - Define a CRC-32 function using the vector extension + * + * Creates a function to perform a particular CRC-32 computation. Depending + * on the message buffer, the hardware-accelerated or software implementation + * is used. Note that the message buffer is aligned to improve fetch + * operations of VECTOR LOAD MULTIPLE instructions. + */ +#define DEFINE_CRC32_VX(___fname, ___crc32_vx, ___crc32_sw) \ + u32 ___fname(u32 crc, const u8 *data, size_t datalen) \ + { \ + unsigned long prealign, aligned, remaining; \ + DECLARE_KERNEL_FPU_ONSTACK16(vxstate); \ + \ + if (datalen < VX_MIN_LEN + VX_ALIGN_MASK || \ + !static_branch_likely(&have_vxrs)) \ + return ___crc32_sw(crc, data, datalen); \ + \ + if ((unsigned long)data & VX_ALIGN_MASK) { \ + prealign = VX_ALIGNMENT - \ + ((unsigned long)data & VX_ALIGN_MASK); \ + datalen -= prealign; \ + crc = ___crc32_sw(crc, data, prealign); \ + data = (void *)((unsigned long)data + prealign); \ + } \ + \ + aligned = datalen & ~VX_ALIGN_MASK; \ + remaining = datalen & VX_ALIGN_MASK; \ + \ + kernel_fpu_begin(&vxstate, KERNEL_VXR_LOW); \ + crc = ___crc32_vx(crc, data, aligned); \ + kernel_fpu_end(&vxstate, KERNEL_VXR_LOW); \ + \ + if (remaining) \ + crc = ___crc32_sw(crc, data + aligned, remaining); \ + \ + return crc; \ + } \ + EXPORT_SYMBOL(___fname); + +DEFINE_CRC32_VX(crc32_le_arch, crc32_le_vgfm_16, crc32_le_base) +DEFINE_CRC32_VX(crc32_be_arch, crc32_be_vgfm_16, crc32_be_base) +DEFINE_CRC32_VX(crc32c_le_arch, crc32c_le_vgfm_16, crc32c_le_base) + +static int __init crc32_s390_init(void) +{ + if (cpu_have_feature(S390_CPU_FEATURE_VXRS)) + static_branch_enable(&have_vxrs); + return 0; +} +arch_initcall(crc32_s390_init); + +static void __exit crc32_s390_exit(void) +{ +} +module_exit(crc32_s390_exit); + +u32 crc32_optimizations(void) +{ + if (static_key_enabled(&have_vxrs)) + return CRC32_LE_OPTIMIZATION | + CRC32_BE_OPTIMIZATION | + CRC32C_OPTIMIZATION; + return 0; +} +EXPORT_SYMBOL(crc32_optimizations); + +MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>"); +MODULE_DESCRIPTION("CRC-32 algorithms using z/Architecture Vector Extension Facility"); +MODULE_LICENSE("GPL"); |