#include <stdint.h>

#include <arm/linux/api.h>
#include <cpuinfo/log.h>


void cpuinfo_arm64_linux_decode_isa_from_proc_cpuinfo(
	uint32_t features,
	uint32_t features2,
	uint32_t midr,
	const struct cpuinfo_arm_chipset chipset[restrict static 1],
	struct cpuinfo_arm_isa isa[restrict static 1])
{
	if (features & CPUINFO_ARM_LINUX_FEATURE_AES) {
		isa->aes = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_PMULL) {
		isa->pmull = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_SHA1) {
		isa->sha1 = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_SHA2) {
		isa->sha2 = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_CRC32) {
		isa->crc32 = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_ATOMICS) {
		isa->atomics = true;
	}

	/*
	 * Some phones ship with an old kernel configuration that doesn't report NEON FP16 compute extension and SQRDMLAH/SQRDMLSH/UQRDMLAH/UQRDMLSH instructions.
	 * Use a MIDR-based heuristic to whitelist processors known to support it:
	 * - Processors with Cortex-A55 cores
	 * - Processors with Cortex-A65 cores
	 * - Processors with Cortex-A75 cores
	 * - Processors with Cortex-A76 cores
	 * - Processors with Cortex-A77 cores
	 * - Processors with Exynos M4 cores
	 * - Processors with Exynos M5 cores
	 * - Neoverse N1 cores
	 * - Neoverse V1 cores
	 * - Neoverse N2 cores
	 */
	if (chipset->series == cpuinfo_arm_chipset_series_samsung_exynos && chipset->model == 9810) {
		/* Exynos 9810 reports that it supports FP16 compute, but in fact only little cores do */
		cpuinfo_log_warning("FP16 arithmetics and RDM disabled: only little cores in Exynos 9810 support these extensions");
	} else {
		const uint32_t fp16arith_mask = CPUINFO_ARM_LINUX_FEATURE_FPHP | CPUINFO_ARM_LINUX_FEATURE_ASIMDHP;
		switch (midr & (CPUINFO_ARM_MIDR_IMPLEMENTER_MASK | CPUINFO_ARM_MIDR_PART_MASK)) {
			case UINT32_C(0x4100D050): /* Cortex-A55 */
			case UINT32_C(0x4100D060): /* Cortex-A65 */
			case UINT32_C(0x4100D0A0): /* Cortex-A75 */
			case UINT32_C(0x4100D0B0): /* Cortex-A76 */
			case UINT32_C(0x4100D0C0): /* Neoverse N1 */
			case UINT32_C(0x4100D0D0): /* Cortex-A77 */
			case UINT32_C(0x4100D0E0): /* Cortex-A76AE */
			case UINT32_C(0x4100D400): /* Neoverse V1 */
			case UINT32_C(0x4100D490): /* Neoverse N2 */
			case UINT32_C(0x4800D400): /* Cortex-A76 (HiSilicon) */
			case UINT32_C(0x51008020): /* Kryo 385 Gold (Cortex-A75) */
			case UINT32_C(0x51008030): /* Kryo 385 Silver (Cortex-A55) */
			case UINT32_C(0x51008040): /* Kryo 485 Gold (Cortex-A76) */
			case UINT32_C(0x51008050): /* Kryo 485 Silver (Cortex-A55) */
			case UINT32_C(0x53000030): /* Exynos M4 */
			case UINT32_C(0x53000040): /* Exynos M5 */
				isa->fp16arith = true;
				isa->rdm = true;
				break;
			default:
				if ((features & fp16arith_mask) == fp16arith_mask) {
					isa->fp16arith = true;
				} else if (features & CPUINFO_ARM_LINUX_FEATURE_FPHP) {
					cpuinfo_log_warning("FP16 arithmetics disabled: detected support only for scalar operations");
				} else if (features & CPUINFO_ARM_LINUX_FEATURE_ASIMDHP) {
					cpuinfo_log_warning("FP16 arithmetics disabled: detected support only for SIMD operations");
				}
				if (features & CPUINFO_ARM_LINUX_FEATURE_ASIMDRDM) {
					isa->rdm = true;
				}
				break;
		}
	}
	if (features2 & CPUINFO_ARM_LINUX_FEATURE2_I8MM) {
		isa->i8mm = true;
	}

	/*
	 * Many phones ship with an old kernel configuration that doesn't report UDOT/SDOT instructions.
	 * Use a MIDR-based heuristic to whitelist processors known to support it.
	 */
	switch (midr & (CPUINFO_ARM_MIDR_IMPLEMENTER_MASK | CPUINFO_ARM_MIDR_PART_MASK)) {
		case UINT32_C(0x4100D060): /* Cortex-A65 */
		case UINT32_C(0x4100D0B0): /* Cortex-A76 */
		case UINT32_C(0x4100D0C0): /* Neoverse N1 */
		case UINT32_C(0x4100D0D0): /* Cortex-A77 */
		case UINT32_C(0x4100D0E0): /* Cortex-A76AE */
		case UINT32_C(0x4100D400): /* Neoverse V1 */
		case UINT32_C(0x4100D490): /* Neoverse N2 */
		case UINT32_C(0x4100D4A0): /* Neoverse E1 */
		case UINT32_C(0x4800D400): /* Cortex-A76 (HiSilicon) */
		case UINT32_C(0x51008040): /* Kryo 485 Gold (Cortex-A76) */
		case UINT32_C(0x51008050): /* Kryo 485 Silver (Cortex-A55) */
		case UINT32_C(0x53000030): /* Exynos-M4 */
		case UINT32_C(0x53000040): /* Exynos-M5 */
			isa->dot = true;
			break;
		case UINT32_C(0x4100D050): /* Cortex A55: revision 1 or later only */
			isa->dot = !!(midr_get_variant(midr) >= 1);
			break;
		case UINT32_C(0x4100D0A0): /* Cortex A75: revision 2 or later only */
			isa->dot = !!(midr_get_variant(midr) >= 2);
			break;
		default:
			if (features & CPUINFO_ARM_LINUX_FEATURE_ASIMDDP) {
				isa->dot = true;
			}
			break;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_JSCVT) {
		isa->jscvt = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_JSCVT) {
		isa->jscvt = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_FCMA) {
		isa->fcma = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_SVE) {
		isa->sve = true;
	}
	if (features2 & CPUINFO_ARM_LINUX_FEATURE2_SVE2) {
		isa->sve2 = true;
	}
	// SVEBF16 is set iff SVE and BF16 are both supported, but the SVEBF16 feature flag
	// was added in Linux kernel before the BF16 feature flag, so we check for either.
	if (features2 & (CPUINFO_ARM_LINUX_FEATURE2_BF16 | CPUINFO_ARM_LINUX_FEATURE2_SVEBF16)) {
		isa->bf16 = true;
	}
	if (features & CPUINFO_ARM_LINUX_FEATURE_ASIMDFHM) {
		isa->fhm = true;
	}
}