From 4684997d9eea29380000e062755aa6d368d789a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Tue, 26 Feb 2019 14:11:19 +0100
Subject: [PATCH] brcmfmac: reset PCIe bus on a firmware crash
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This includes bus reset & reloading a firmware. It should be sufficient
for a user space to (setup and) use a wireless device again.

Support for reset on USB & SDIO can be added later.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---
 .../broadcom/brcm80211/brcmfmac/bus.h         | 10 ++++++
 .../broadcom/brcm80211/brcmfmac/core.c        | 12 +++++++
 .../broadcom/brcm80211/brcmfmac/core.h        |  2 ++
 .../broadcom/brcm80211/brcmfmac/pcie.c        | 35 +++++++++++++++++++
 4 files changed, 59 insertions(+)

--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h
@@ -90,6 +90,7 @@ struct brcmf_bus_ops {
 	int (*get_memdump)(struct device *dev, void *data, size_t len);
 	int (*get_fwname)(struct device *dev, const char *ext,
 			  unsigned char *fw_name);
+	int (*reset)(struct device *dev);
 };
 
 
@@ -235,6 +236,15 @@ int brcmf_bus_get_fwname(struct brcmf_bu
 	return bus->ops->get_fwname(bus->dev, ext, fw_name);
 }
 
+static inline
+int brcmf_bus_reset(struct brcmf_bus *bus)
+{
+	if (!bus->ops->reset)
+		return -EOPNOTSUPP;
+
+	return bus->ops->reset(bus->dev);
+}
+
 /*
  * interface functions from common layer
  */
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
@@ -1104,6 +1104,14 @@ static int brcmf_revinfo_read(struct seq
 	return 0;
 }
 
+static void brcmf_core_bus_reset(struct work_struct *work)
+{
+	struct brcmf_pub *drvr = container_of(work, struct brcmf_pub,
+					      bus_reset);
+
+	brcmf_bus_reset(drvr->bus_if);
+}
+
 static int brcmf_bus_started(struct brcmf_pub *drvr, struct cfg80211_ops *ops)
 {
 	int ret = -1;
@@ -1175,6 +1183,8 @@ static int brcmf_bus_started(struct brcm
 #endif
 #endif /* CONFIG_INET */
 
+	INIT_WORK(&drvr->bus_reset, brcmf_core_bus_reset);
+
 	/* populate debugfs */
 	brcmf_debugfs_add_entry(drvr, "revinfo", brcmf_revinfo_read);
 	brcmf_feat_debugfs_create(drvr);
@@ -1300,6 +1310,8 @@ void brcmf_fw_crashed(struct device *dev
 	bphy_err(drvr, "Firmware has halted or crashed\n");
 
 	brcmf_dev_coredump(dev);
+
+	schedule_work(&drvr->bus_reset);
 }
 
 void brcmf_detach(struct device *dev)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
@@ -143,6 +143,8 @@ struct brcmf_pub {
 	struct notifier_block inet6addr_notifier;
 	struct brcmf_mp_device *settings;
 
+	struct work_struct bus_reset;
+
 	u8 clmver[BRCMF_DCMD_SMLEN];
 };
 
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
@@ -345,6 +345,10 @@ static const u32 brcmf_ring_itemsize[BRC
 	BRCMF_D2H_MSGRING_RX_COMPLETE_ITEMSIZE
 };
 
+static void brcmf_pcie_setup(struct device *dev, int ret,
+			     struct brcmf_fw_request *fwreq);
+static struct brcmf_fw_request *
+brcmf_pcie_prepare_fw_request(struct brcmf_pciedev_info *devinfo);
 
 static u32
 brcmf_pcie_read_reg32(struct brcmf_pciedev_info *devinfo, u32 reg_offset)
@@ -1409,6 +1413,36 @@ int brcmf_pcie_get_fwname(struct device
 	return 0;
 }
 
+static int brcmf_pcie_reset(struct device *dev)
+{
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_pciedev *buspub = bus_if->bus_priv.pcie;
+	struct brcmf_pciedev_info *devinfo = buspub->devinfo;
+	struct brcmf_fw_request *fwreq;
+	int err;
+
+	brcmf_detach(dev);
+
+	brcmf_pcie_release_irq(devinfo);
+	brcmf_pcie_release_scratchbuffers(devinfo);
+	brcmf_pcie_release_ringbuffers(devinfo);
+	brcmf_pcie_reset_device(devinfo);
+
+	fwreq = brcmf_pcie_prepare_fw_request(devinfo);
+	if (!fwreq) {
+		dev_err(dev, "Failed to prepare FW request\n");
+		return -ENOMEM;
+	}
+
+	err = brcmf_fw_get_firmwares(dev, fwreq, brcmf_pcie_setup);
+	if (err) {
+		dev_err(dev, "Failed to prepare FW request\n");
+		kfree(fwreq);
+	}
+
+	return err;
+}
+
 static const struct brcmf_bus_ops brcmf_pcie_bus_ops = {
 	.txdata = brcmf_pcie_tx,
 	.stop = brcmf_pcie_down,
@@ -1418,6 +1452,7 @@ static const struct brcmf_bus_ops brcmf_
 	.get_ramsize = brcmf_pcie_get_ramsize,
 	.get_memdump = brcmf_pcie_get_memdump,
 	.get_fwname = brcmf_pcie_get_fwname,
+	.reset = brcmf_pcie_reset,
 };