!1083 LoongArch: fix system hang caused by 2k500 bmc driver

Merge Pull Request from: @Hongchen_Zhang 
 
when we test the 2k500 bmc,the system hang when send the following command:
[loongson@localhost ~]# ipmi mc reset cold

After apply this PR,the problem disappeared. 
 
Link:https://gitee.com/openeuler/kernel/pulls/1083 

Reviewed-by: Guo Dongtai <guodongtai@kylinos.cn> 
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> 

drivers/char/ipmi/btlock.h

@@ -19,6 +19,7 @@ static inline int btlock_lock(volatile union btlock *p, int n, unsigned char del
 {
 	union btlock t, t1;
 	unsigned long flags;
+	unsigned long c0 = get_cycles(), c1;
 
 	if (n > 1)
 		return -1;
@@ -39,7 +40,10 @@ static inline int btlock_lock(volatile union btlock *p, int n, unsigned char del
 		t.u = p->u;
 		wmb(); /* flush write out immediately */
 		local_irq_restore(flags);
-		ndelay(((t.b[1 - n] & 0x7f) + (get_cycles() & 1)) * 100);
+		c1 = get_cycles();
+		if (c1 - c0 > *mscycles * 1000)
+			return -1;
+		ndelay(((t.b[1 - n] & 0x7f) + (c1 & 1)) * 100);
 	}
 	return 0;
 }

drivers/char/ipmi/ipmi_si_ls2k500.c

@@ -18,17 +18,31 @@
 #include <linux/ioport.h>
 #include <linux/version.h>
 #include "ipmi_si.h"
+static unsigned long *mscycles;
+static unsigned long *event_jiffies;
 #include "kcs_bmc_ls2k500.h"
+static int resetbootwait = 60;
+module_param(resetbootwait, int, 0664);
 
 #define KCS_STATUS_CMD_DAT      BIT(3)
 
+static int pcie_busy(void)
+{
+	if (time_before(jiffies, *event_jiffies + resetbootwait*HZ))
+		return -1;
+	return 0;
+}
+
 static unsigned char intf_sim_inb(const struct si_sm_io *io,
 				  unsigned int offset)
 {
 	IPMIKCS *ik = io->addr_source_data;
 	uint32_t ret;
 
-	btlock_lock(&ik->lock, 0, 1);
+	if (pcie_busy())
+		return 0;
+	if (btlock_lock(&ik->lock, 0, 1) < 0)
+		return 0;
 	switch (offset & 1) {
 	case 0:
 		ret = ik->data_out_reg;
@@ -47,7 +61,10 @@ static void intf_sim_outb(const struct si_sm_io *io, unsigned int offset,
 {
 	IPMIKCS *ik = io->addr_source_data;
 
-	btlock_lock(&ik->lock, 0, 1);
+	if (pcie_busy())
+		return;
+	if (btlock_lock(&ik->lock, 0, 1) < 0)
+		return;
 	if (IPMI_KCS_GET_IBF(ik->status_reg))
 		goto out;
 
@@ -86,7 +103,7 @@ static int of_ipmi_ls2k500_probe(struct platform_device *pdev)
 {
 	int rv;
 	struct si_sm_io io;
-
+	void **kcs_data;
 	memset(&io, 0, sizeof(io));
 	io.addr_source = SI_PLATFORM;
 	dev_info(&pdev->dev, "probing via ls2k500 platform");
@@ -100,6 +117,9 @@ static int of_ipmi_ls2k500_probe(struct platform_device *pdev)
 	io.addr_source_data = ioremap(pdev->resource[0].start,
 					pdev->resource[0].end -
 					pdev->resource[0].start + 1);
+	kcs_data = dev_get_platdata(&pdev->dev);
+	event_jiffies = kcs_data[0];
+	mscycles = kcs_data[1];
 	io.dev = &pdev->dev;
 	io.regspacing = 4;
 	io.regsize = DEFAULT_REGSIZE;
@@ -112,6 +132,8 @@ static int of_ipmi_ls2k500_probe(struct platform_device *pdev)
 		&pdev->resource[0], io.regsize, io.regspacing, io.irq);
 
 	rv = ipmi_si_add_smi(&io);
+	if (rv)
+		ipmi_si_remove_by_dev(&pdev->dev);
 
 	return rv;
 }

drivers/video/fbdev/ls2k500sfb.c

@@ -108,6 +108,7 @@ static void ls2k500sfb_redraw_fn(struct work_struct *work)
 	switch_console(saved_console);
 }
 
+static unsigned long event_jiffies;
 static void ls2k500sfb_events_fn(struct work_struct *work)
 {
 	struct ls2k500sfb_struct *priv = container_of(work, struct ls2k500sfb_struct, work);
@@ -148,6 +149,7 @@ static void ls2k500sfb_events_fn(struct work_struct *work)
 	pci_write_config_dword(ppdev, 0x18, 0);
 	pci_write_config_dword(ppdev, 0x1c, 0);
 	pci_write_config_dword(ppdev, 0x20, 0);
+	event_jiffies = jiffies;
 	atomic_set(&waiting_for_pciebreak_ipi, 0);
 	wmb(); /* flush all write after change pcie window */
 	local_bh_enable();
@@ -645,6 +647,7 @@ static struct platform_driver simplefb_driver = {
 	.remove = simplefb_remove,
 };
 
+static void *kcs_data[2] = {&event_jiffies, &mscycles};
 static int ls2k500sfb_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	struct simplefb_platform_data mode;
@@ -737,7 +740,8 @@ static int ls2k500sfb_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	for (i = 0; i < 5; i++) {
 		res[0].start = phybase + 0x00f00000 + 0x1c*i;
 		res[0].end = phybase + 0x00f00000 + 0x1c*(i+1) - 1;
-		platform_device_register_simple("ipmi_ls2k500_si", i, res, 1);
+		platform_device_register_resndata(NULL, "ipmi_ls2k500_si", i, res, 1,
+						kcs_data, sizeof(kcs_data));
 	}
 
 	return PTR_ERR_OR_ZERO(pd);