xref: /dpdk/drivers/common/mlx5/mlx5_common.c (revision 25245d5dc9ecfa8bc9964c69a756beca6ee1ca72)

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright 2019 Mellanox Technologies, Ltd
 */

#include <unistd.h>
#include <string.h>
#include <stdio.h>

#include <rte_errno.h>
#include <rte_mempool.h>

#include "mlx5_common.h"
#include "mlx5_common_os.h"
#include "mlx5_common_log.h"
#include "mlx5_common_pci.h"

uint8_t haswell_broadwell_cpu;

/* In case this is an x86_64 intel processor to check if
 * we should use relaxed ordering.
 */
#ifdef RTE_ARCH_X86_64
/**
 * This function returns processor identification and feature information
 * into the registers.
 *
 * @param eax, ebx, ecx, edx
 *		Pointers to the registers that will hold cpu information.
 * @param level
 *		The main category of information returned.
 */
static inline void mlx5_cpu_id(unsigned int level,
				unsigned int *eax, unsigned int *ebx,
				unsigned int *ecx, unsigned int *edx)
{
	__asm__("cpuid\n\t"
		: "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx)
		: "0" (level));
}
#endif

RTE_LOG_REGISTER(mlx5_common_logtype, pmd.common.mlx5, NOTICE)

static bool mlx5_common_initialized;

/**
 * One time innitialization routine for run-time dependency on glue library
 * for multiple PMDs. Each mlx5 PMD that depends on mlx5_common module,
 * must invoke in its constructor.
 */
void
mlx5_common_init(void)
{
	if (mlx5_common_initialized)
		return;

	mlx5_glue_constructor();
	mlx5_common_pci_init();
	mlx5_common_initialized = true;
}

/**
 * This function is responsible of initializing the variable
 *  haswell_broadwell_cpu by checking if the cpu is intel
 *  and reading the data returned from mlx5_cpu_id().
 *  since haswell and broadwell cpus don't have improved performance
 *  when using relaxed ordering we want to check the cpu type before
 *  before deciding whether to enable RO or not.
 *  if the cpu is haswell or broadwell the variable will be set to 1
 *  otherwise it will be 0.
 */
RTE_INIT_PRIO(mlx5_is_haswell_broadwell_cpu, LOG)
{
#ifdef RTE_ARCH_X86_64
	unsigned int broadwell_models[4] = {0x3d, 0x47, 0x4F, 0x56};
	unsigned int haswell_models[4] = {0x3c, 0x3f, 0x45, 0x46};
	unsigned int i, model, family, brand_id, vendor;
	unsigned int signature_intel_ebx = 0x756e6547;
	unsigned int extended_model;
	unsigned int eax = 0;
	unsigned int ebx = 0;
	unsigned int ecx = 0;
	unsigned int edx = 0;
	int max_level;

	mlx5_cpu_id(0, &eax, &ebx, &ecx, &edx);
	vendor = ebx;
	max_level = eax;
	if (max_level < 1) {
		haswell_broadwell_cpu = 0;
		return;
	}
	mlx5_cpu_id(1, &eax, &ebx, &ecx, &edx);
	model = (eax >> 4) & 0x0f;
	family = (eax >> 8) & 0x0f;
	brand_id = ebx & 0xff;
	extended_model = (eax >> 12) & 0xf0;
	/* Check if the processor is Haswell or Broadwell */
	if (vendor == signature_intel_ebx) {
		if (family == 0x06)
			model += extended_model;
		if (brand_id == 0 && family == 0x6) {
			for (i = 0; i < RTE_DIM(broadwell_models); i++)
				if (model == broadwell_models[i]) {
					haswell_broadwell_cpu = 1;
					return;
				}
			for (i = 0; i < RTE_DIM(haswell_models); i++)
				if (model == haswell_models[i]) {
					haswell_broadwell_cpu = 1;
					return;
				}
		}
	}
#endif
	haswell_broadwell_cpu = 0;
}

/**
 * Allocate the User Access Region with DevX on specified device.
 *
 * @param [in] ctx
 *   Infiniband device context to perform allocation on.
 * @param [in] mapping
 *   MLX5DV_UAR_ALLOC_TYPE_BF - allocate as cached memory with write-combining
 *				attributes (if supported by the host), the
 *				writes to the UAR registers must be followed
 *				by write memory barrier.
 *   MLX5DV_UAR_ALLOC_TYPE_NC - allocate as non-cached nenory, all writes are
 *				promoted to the registers immediately, no
 *				memory barriers needed.
 *   mapping < 0 - the first attempt is performed with MLX5DV_UAR_ALLOC_TYPE_BF,
 *		   if this fails the next attempt with MLX5DV_UAR_ALLOC_TYPE_NC
 *		   is performed. The drivers specifying negative values should
 *		   always provide the write memory barrier operation after UAR
 *		   register writings.
 * If there is no definitions for the MLX5DV_UAR_ALLOC_TYPE_xx (older rdma
 * library headers), the caller can specify 0.
 *
 * @return
 *   UAR object pointer on success, NULL otherwise and rte_errno is set.
 */
void *
mlx5_devx_alloc_uar(void *ctx, int mapping)
{
	void *uar;
	uint32_t retry, uar_mapping;
	void *base_addr;

	for (retry = 0; retry < MLX5_ALLOC_UAR_RETRY; ++retry) {
#ifdef MLX5DV_UAR_ALLOC_TYPE_NC
		/* Control the mapping type according to the settings. */
		uar_mapping = (mapping < 0) ?
			      MLX5DV_UAR_ALLOC_TYPE_NC : mapping;
#else
		/*
		 * It seems we have no way to control the memory mapping type
		 * for the UAR, the default "Write-Combining" type is supposed.
		 */
		uar_mapping = 0;
		RTE_SET_USED(mapping);
#endif
		uar = mlx5_glue->devx_alloc_uar(ctx, uar_mapping);
#ifdef MLX5DV_UAR_ALLOC_TYPE_NC
		if (!uar &&
		    mapping < 0 &&
		    uar_mapping == MLX5DV_UAR_ALLOC_TYPE_BF) {
			/*
			 * In some environments like virtual machine the
			 * Write Combining mapped might be not supported and
			 * UAR allocation fails. We tried "Non-Cached" mapping
			 * for the case.
			 */
			DRV_LOG(WARNING, "Failed to allocate DevX UAR (BF)");
			uar_mapping = MLX5DV_UAR_ALLOC_TYPE_NC;
			uar = mlx5_glue->devx_alloc_uar(ctx, uar_mapping);
		} else if (!uar &&
			   mapping < 0 &&
			   uar_mapping == MLX5DV_UAR_ALLOC_TYPE_NC) {
			/*
			 * If Verbs/kernel does not support "Non-Cached"
			 * try the "Write-Combining".
			 */
			DRV_LOG(WARNING, "Failed to allocate DevX UAR (NC)");
			uar_mapping = MLX5DV_UAR_ALLOC_TYPE_BF;
			uar = mlx5_glue->devx_alloc_uar(ctx, uar_mapping);
		}
#endif
		if (!uar) {
			DRV_LOG(ERR, "Failed to allocate DevX UAR (BF/NC)");
			rte_errno = ENOMEM;
			goto exit;
		}
		base_addr = mlx5_os_get_devx_uar_base_addr(uar);
		if (base_addr)
			break;
		/*
		 * The UARs are allocated by rdma_core within the
		 * IB device context, on context closure all UARs
		 * will be freed, should be no memory/object leakage.
		 */
		DRV_LOG(WARNING, "Retrying to allocate DevX UAR");
		uar = NULL;
	}
	/* Check whether we finally succeeded with valid UAR allocation. */
	if (!uar) {
		DRV_LOG(ERR, "Failed to allocate DevX UAR (NULL base)");
		rte_errno = ENOMEM;
	}
	/*
	 * Return void * instead of struct mlx5dv_devx_uar *
	 * is for compatibility with older rdma-core library headers.
	 */
exit:
	return uar;
}