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Tomasz Bursztykanashif
Tomasz Bursztyka
authored and
nashif
committed
drivers/pcie: Add VC/TC mapping and VC enablement
Note that only the the hardware round robin port arbitration capability is being used. Signed-off-by: Tomasz Bursztyka <[email protected]>
1 parent 6a1e19c commit 0c9e762

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4 files changed

+221
-5
lines changed

4 files changed

+221
-5
lines changed

‎drivers/pcie/host/shell.c

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Original file line numberDiff line numberDiff line change
@@ -14,6 +14,7 @@
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#include <zephyr/drivers/pcie/cap.h>
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#include <zephyr/drivers/pcie/vc.h>
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#include "vc.h"
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struct pcie_cap_id_to_str {

‎drivers/pcie/host/vc.c

Lines changed: 118 additions & 3 deletions
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@@ -6,9 +6,7 @@
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#include <errno.h>
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9-
#include <zephyr/kernel.h>
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#include <zephyr/drivers/pcie/pcie.h>
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#include <zephyr/drivers/pcie/vc.h>
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#include <zephyr/drivers/pcie/cap.h>
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#include "vc.h"
@@ -55,3 +53,120 @@ void pcie_vc_load_resources_regs(pcie_bdf_t bdf,
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regs++;
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}
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}
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static int get_vc_registers(pcie_bdf_t bdf,
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struct pcie_vc_regs *regs,
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struct pcie_vc_resource_regs *res_regs)
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{
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uint32_t base;
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base = pcie_vc_cap_lookup(bdf, regs);
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if (base == 0) {
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return -ENOTSUP;
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}
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if (regs->cap_reg_1.vc_count == 0) {
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/* Having only VC0 is like having no real VC */
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return -ENOTSUP;
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}
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pcie_vc_load_resources_regs(bdf, base, res_regs,
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regs->cap_reg_1.vc_count + 1);
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return 0;
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}
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int pcie_vc_enable(pcie_bdf_t bdf)
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{
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struct pcie_vc_regs regs;
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struct pcie_vc_resource_regs res_regs[PCIE_VC_MAX_COUNT];
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int idx;
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if (get_vc_registers(bdf, &regs, res_regs) != 0) {
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return -ENOTSUP;
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}
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/* We do not touch VC0: it is always on */
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for (idx = 1; idx < regs.cap_reg_1.vc_count + 1; idx++) {
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if (idx > 0 && res_regs[idx].ctrl_reg.vc_enable == 1) {
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/*
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* VC has not been disabled properly, if at all?
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*/
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return -EALREADY;
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}
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res_regs[idx].ctrl_reg.vc_enable = 1;
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}
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return 0;
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}
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int pcie_vc_disable(pcie_bdf_t bdf)
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{
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struct pcie_vc_regs regs;
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struct pcie_vc_resource_regs res_regs[PCIE_VC_MAX_COUNT];
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int idx;
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if (get_vc_registers(bdf, &regs, res_regs) != 0) {
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return -ENOTSUP;
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}
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/* We do not touch VC0: it is always on */
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for (idx = 1; idx < regs.cap_reg_1.vc_count + 1; idx++) {
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/* Let's wait for the pending negotiation to end */
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while (res_regs[idx].status_reg.vc_negocation_pending == 1) {
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k_msleep(10);
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}
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res_regs[idx].ctrl_reg.vc_enable = 0;
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}
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return 0;
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}
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int pcie_vc_map_tc(pcie_bdf_t bdf, struct pcie_vctc_map *map)
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{
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struct pcie_vc_regs regs;
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struct pcie_vc_resource_regs res_regs[PCIE_VC_MAX_COUNT];
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int idx;
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uint8_t tc_mapped = 0;
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if (get_vc_registers(bdf, &regs, res_regs) != 0) {
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return -ENOTSUP;
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}
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/* Map must relate to the actual VC count */
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if (regs.cap_reg_1.vc_count != map->vc_count) {
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return -EINVAL;
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}
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/* Veryfying that map is sane */
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for (idx = 0; idx < map->vc_count; idx++) {
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if (idx == 0 && !(map->vc_tc[idx] & PCIE_VC_SET_TC0)) {
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/* TC0 is on VC0 and cannot be unset */
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return -EINVAL;
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}
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/* Each TC must appear only once in the map */
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if (tc_mapped & map->vc_tc[idx]) {
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return -EINVAL;
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}
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tc_mapped |= map->vc_tc[idx];
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}
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for (idx = 0; idx < regs.cap_reg_1.vc_count + 1; idx++) {
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/* Let's just set the VC ID to related index for now */
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if (idx > 0) {
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res_regs[idx].ctrl_reg.vc_id = idx;
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}
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/* Currently, only HW round robin is used */
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res_regs[idx].ctrl_reg.pa_select = PCIE_VC_PA_RR;
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res_regs[idx].ctrl_reg.tc_vc_map = map->vc_tc[idx];
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}
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return 0;
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}

‎drivers/pcie/host/vc.h

Lines changed: 7 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -7,8 +7,6 @@
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#ifndef ZEPHYR_DRIVERS_PCIE_HOST_VC_H_
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#define ZEPHYR_DRIVERS_PCIE_HOST_VC_H_
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10-
#define PCIE_VC_MAX_COUNT 8
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#define PCIE_VC_CAP_REG_1_OFFSET 0x04U
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#define PCIE_VC_CAP_REG_2_OFFSET 0x08U
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#define PCIE_VC_CTRL_STATUS_REG_OFFSET 0x0CU
@@ -62,6 +60,13 @@ struct pcie_vc_regs {
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#define PCIE_VC_RES_CTRL_REG_OFFSET(_vc) (0x14U + _vc * 0X0CU)
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#define PCIE_VC_RES_STATUS_REG_OFFSET(_vc) (0x18U + _vc * 0X0CU)
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#define PCIE_VC_PA_RR BIT(0)
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#define PCIE_VC_PA_WRR BIT(1)
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#define PCIE_VC_PA_WRR64 BIT(2)
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#define PCIE_VC_PA_WRR128 BIT(3)
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#define PCIE_VC_PA_TMWRR128 BIT(4)
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#define PCIE_VC_PA_WRR256 BIT(5)
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/** Virtual Channel Resource Registers */
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struct pcie_vc_resource_regs {
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union {

‎include/zephyr/drivers/pcie/vc.h

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,95 @@
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/*
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* Copyright (c) 2023 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef ZEPHYR_INCLUDE_DRIVERS_PCIE_VC_H_
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#define ZEPHYR_INCLUDE_DRIVERS_PCIE_VC_H_
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/**
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* @brief PCIe Virtual Channel Host Interface
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* @defgroup pcie_vc_host_interface PCIe Virtual Channel Host Interface
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* @ingroup pcie_host_interface
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* @{
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <zephyr/kernel.h>
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#include <zephyr/types.h>
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#include <stdbool.h>
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#include <zephyr/drivers/pcie/pcie.h>
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/*
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* 1 default VC + 7 extended VCs
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*/
30+
#define PCIE_VC_MAX_COUNT 8U
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32+
#define PCIE_VC_SET_TC0 BIT(0)
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#define PCIE_VC_SET_TC1 BIT(1)
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#define PCIE_VC_SET_TC2 BIT(2)
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#define PCIE_VC_SET_TC3 BIT(3)
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#define PCIE_VC_SET_TC4 BIT(4)
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#define PCIE_VC_SET_TC5 BIT(5)
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#define PCIE_VC_SET_TC6 BIT(6)
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#define PCIE_VC_SET_TC7 BIT(7)
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struct pcie_vctc_map {
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/*
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* Map the TCs for each VC by setting bits relevantly
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* Note: one bit cannot be set more than once among the VCs
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*/
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uint8_t vc_tc[PCIE_VC_MAX_COUNT];
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/*
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* Number of VCs being addressed
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*/
50+
int vc_count;
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};
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53+
/**
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* @brief Enable PCIe Virtual Channel handling
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* @param bdf the target PCI endpoint
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* @return 0 on success, a negative error code otherwise
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*
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* Note: Not being able to enable such feature is a non-fatal error
59+
* and any code using it should behave accordingly (displaying some info,
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* and ignoring it for instance).
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*/
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int pcie_vc_enable(pcie_bdf_t bdf);
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/**
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* @brief Disable PCIe Virtual Channel handling
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* @param bdf the target PCI endpoint
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* @return 0 on success, a negative error code otherwise
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*/
69+
int pcie_vc_disable(pcie_bdf_t bdf);
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/**
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* @brief Map PCIe TC/VC
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* @param bdf the target PCI endpoint
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* @param map the tc/vc map to apply
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* @return 0 on success, a negative error code otherwise
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*
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* Note: VC must be disabled prior to call this function and
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* enabled afterward in order for the endpoint to take advandage of the map.
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*
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* Note: Not being able to enable such feature is a non-fatal error
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* and any code using it should behave accordingly (displaying some info,
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* and ignoring it for instance).
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*/
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int pcie_vc_map_tc(pcie_bdf_t bdf, struct pcie_vctc_map *map);
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#ifdef __cplusplus
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}
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#endif
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/**
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* @}
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*/
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#endif /* ZEPHYR_INCLUDE_DRIVERS_PCIE_VC_H_ */

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