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pci: msm: Add support to handle ep driver requested link down

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In case PCIe endpoint driver infers link down because of
completion timeout for config space access or if link fails
to enumerate, ep driver can request to handle the link down.
This allows to stream line the link down notification to ep
driver to initiate recovery operation.

Change-Id: I652e60e570c1e90c9f96d1c197e4b5501cd60a1e
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
This commit is contained in:
Hemant Kumar 2020-08-10 17:16:38 -07:00 committed by Gerrit - the friendly Code Review server
parent ac3ef5b43d
commit 4e2f7cbc9d
2 changed files with 53 additions and 39 deletions
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89
drivers/pci/controller/pci-msm.c
View file

@ -5034,10 +5034,48 @@ static irqreturn_t handle_wake_irq(int irq, void *data)
return IRQ_HANDLED;
}
static void msm_pcie_handle_linkdown(struct msm_pcie_dev_t *dev)
{
int i;
if (dev->link_status == MSM_PCIE_LINK_DOWN)
return;
dev->link_status = MSM_PCIE_LINK_DOWN;
dev->shadow_en = false;
/* PCIe registers dump on link down */
PCIE_DUMP(dev, "PCIe:Linkdown IRQ for RC%d Dumping PCIe registers\n",
dev->rc_idx);
pcie_phy_dump(dev);
pcie_parf_dump(dev);
pcie_dm_core_dump(dev);
/* assert PERST */
if (!(msm_pcie_keep_resources_on & BIT(dev->rc_idx)))
gpio_set_value(dev->gpio[MSM_PCIE_GPIO_PERST].num,
dev->gpio[MSM_PCIE_GPIO_PERST].on);
PCIE_ERR(dev, "PCIe link is down for RC%d\n", dev->rc_idx);
if (dev->linkdown_panic)
panic("User has chosen to panic on linkdown\n");
if (dev->num_ep > 1) {
for (i = 0; i < MAX_DEVICE_NUM; i++) {
dev->event_reg =
dev->pcidev_table[i].event_reg;
msm_pcie_notify_client(dev,
MSM_PCIE_EVENT_LINKDOWN);
}
} else {
msm_pcie_notify_client(dev, MSM_PCIE_EVENT_LINKDOWN);
}
}
static irqreturn_t handle_linkdown_irq(int irq, void *data)
{
struct msm_pcie_dev_t *dev = data;
int i;
dev->linkdown_counter++;
@ -5045,49 +5083,16 @@ static irqreturn_t handle_linkdown_irq(int irq, void *data)
"PCIe: No. %ld linkdown IRQ for RC%d.\n",
dev->linkdown_counter, dev->rc_idx);
if (!dev->enumerated || dev->link_status != MSM_PCIE_LINK_ENABLED) {
if (!dev->enumerated || dev->link_status != MSM_PCIE_LINK_ENABLED)
PCIE_DBG(dev,
"PCIe:Linkdown IRQ for RC%d when the link is not enabled\n",
dev->rc_idx);
} else if (dev->suspending) {
else if (dev->suspending)
PCIE_DBG(dev,
"PCIe:the link of RC%d is suspending.\n",
dev->rc_idx);
} else {
dev->link_status = MSM_PCIE_LINK_DOWN;
dev->shadow_en = false;
/* PCIe registers dump on link down */
if ((dev->rc_idx == 0) || (dev->rc_idx == 2)) {
PCIE_DUMP(dev,
"PCIe:Linkdown IRQ for RC%d Dumping PCIe registers\n",
dev->rc_idx);
pcie_phy_dump(dev);
pcie_parf_dump(dev);
pcie_dm_core_dump(dev);
}
if (dev->linkdown_panic)
panic("User has chosen to panic on linkdown\n");
/* assert PERST */
if (!(msm_pcie_keep_resources_on & BIT(dev->rc_idx)))
gpio_set_value(dev->gpio[MSM_PCIE_GPIO_PERST].num,
dev->gpio[MSM_PCIE_GPIO_PERST].on);
PCIE_ERR(dev, "PCIe link is down for RC%d\n", dev->rc_idx);
if (dev->num_ep > 1) {
for (i = 0; i < MAX_DEVICE_NUM; i++) {
dev->event_reg =
dev->pcidev_table[i].event_reg;
msm_pcie_notify_client(dev,
MSM_PCIE_EVENT_LINKDOWN);
}
} else {
msm_pcie_notify_client(dev, MSM_PCIE_EVENT_LINKDOWN);
}
}
else
msm_pcie_handle_linkdown(dev);
return IRQ_HANDLED;
}
@ -7151,6 +7156,7 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user,
int ret = 0;
struct pci_dev *dev;
u32 rc_idx = 0;
unsigned long flags;
struct msm_pcie_dev_t *pcie_dev;
PCIE_GEN_DBG("PCIe: pm_opt:%d;busnr:%d;options:%d\n",
@ -7300,6 +7306,13 @@ int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr, void *user,
spin_unlock_irqrestore(&msm_pcie_dev[rc_idx].cfg_lock,
msm_pcie_dev[rc_idx].irqsave_flags);
break;
case MSM_PCIE_HANDLE_LINKDOWN:
PCIE_DBG(&msm_pcie_dev[rc_idx],
"User of RC%d requests handling link down.\n", rc_idx);
spin_lock_irqsave(&msm_pcie_dev[rc_idx].irq_lock, flags);
msm_pcie_handle_linkdown(pcie_dev);
spin_unlock_irqrestore(&msm_pcie_dev[rc_idx].irq_lock, flags);
break;
default:
PCIE_ERR(&msm_pcie_dev[rc_idx],
"PCIe: RC%d: unsupported pm operation:%d.\n",

3
include/linux/msm_pcie.h
View file

@ -1,5 +1,5 @@
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2014-2019, The Linux Foundation. All rights reserved.*/
/* Copyright (c) 2014-2020, The Linux Foundation. All rights reserved.*/
#ifndef __MSM_PCIE_H
#define __MSM_PCIE_H
@ -21,6 +21,7 @@ enum msm_pcie_pm_opt {
MSM_PCIE_RESUME,
MSM_PCIE_DISABLE_PC,
MSM_PCIE_ENABLE_PC,
MSM_PCIE_HANDLE_LINKDOWN,
};
enum msm_pcie_event {