mt7628 pcie挂载nvme并测试

默认情况下openwrt并没有启用nvme特性

需要使用make kernel_menuconfig 进入 Device 设置并启用NVMe

编译后启动内核panic如下


[    0.810128] Kernel bug detected[#1]:
[    0.813779] CPU: 0 PID: 9 Comm: kworker/u2:1 Not tainted 4.14.162 #0
[    0.820240] Workqueue: nvme-wq nvme_reset_work
[    0.824749] task: 87c22d00 task.stack: 87cfa000
[    0.829336] $ 0   : 00000000 00000001 80276b18 00000001
[    0.834642] $ 4   : 87c1f8e8 00000000 87cfbd70 87d55c00
[    0.839948] $ 8   : 00000000 00000008 00000000 00000001
[    0.845252] $12   : 00000000 00000400 ffffffff 00000000
[    0.850556] $16   : 87c1f8e8 87c1f844 87c1f800 804c0000
[    0.855862] $20   : 87cf6c00 00000000 87c1f8e8 00000088
[    0.861169] $24   : 00000400 c71307b5
[    0.866475] $28   : 87cfa000 87cfbd50 804d0000 802752e4
[    0.871784] Hi    : 00000000
[    0.874699] Lo    : 00000001
[    0.877624] epc   : 80276b18 nvme_pci_reg_read64+0x0/0x4
[    0.883012] ra    : 802752e4 nvme_init_identify+0x94/0x6e0
[    0.888568] Status: 11009403 KERNEL EXL IE
[    0.892819] Cause : 10800024 (ExcCode 09)
[    0.896883] PrId  : 00019655 (MIPS 24KEc)
[    0.900942] Modules linked in:
[    0.904045] Process kworker/u2:1 (pid: 9, threadinfo=87cfa000, task=87c22d00, tls=00000000)
[    0.912506] Stack : 80038118 87c22d00 87e11600 87c1f844 87c1f800 87e11600 87c1f844 87c1f870
[    0.920994]         87c1f87c 87cf6c00 00000000 801f35d4 87cf6c00 87c1f844 00000000 00000000
[    0.929478]         87c1f844 87c1f844 87e11600 87c1f800 87ce9680 c71307b5 87c1f938 87c1f844
[    0.937964]         87c1f800 87ce9680 87cf6c00 00000000 87c1f8e8 802785f8 87cb6198 00000000
[    0.946448]         00000000 80024450 00000002 8003516c 87ce9d00 87c22d00 00000000 00000000
[    0.954932]         ...
[    0.957413] Call Trace:
[    0.959894] [<80276b18>] nvme_pci_reg_read64+0x0/0x4
[    0.964930] [<802752e4>] nvme_init_identify+0x94/0x6e0
[    0.970142] [<802785f8>] nvme_reset_work+0x488/0x1164

IDA反汇编后发现上述崩溃点的代码竟然是

.text:000011E8  # =============== S U B R O U T I N E =======================================
.text:000011E8
.text:000011E8
.text:000011E8 nvme_pci_reg_read64:                     # DATA XREF: .rodata:00004570↓o
.text:000011E8                 break   0x3000
.text:000011E8  # End of function nvme_pci_reg_read64

查看源代码 drivers/nvme/host/pci.c


static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
{
	*val = readq(to_nvme_dev(ctrl)->bar + off);
	return 0;
}

可能是mips这个平台并没有readq这个函数，寻找其他readq发现


	/*
	 * Some devices and/or platforms don't advertise or work with INTx
	 * interrupts. Pre-enable a single MSIX or MSI vec for setup. We'll
	 * adjust this later.
	 */
	result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
	if (result < 0)
		return result;

	dev->ctrl.cap = lo_hi_readq(dev->bar + NVME_REG_CAP);

这可能是一个workaround，所以把上述代码的readq改成lo_hi_readq即可，如下


static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
{
	*val = lo_hi_readq(to_nvme_dev(ctrl)->bar + off);
	return 0;
}

编译openwrt并刷机启动，果然识别到了nvme (建兴T11 Plus 256G)

root@OpenWrt:/# lspci
00:00.0 PCI bridge: MEDIATEK Corp. Device 0801 (rev 01)
01:00.0 Non-Volatile memory controller: Lite-On Technology Corporation Device 5100 (rev 01)
root@OpenWrt:/# ls /dev/nvme*
/dev/nvme0      /dev/nvme0n1    /dev/nvme0n1p1

挂载ext4分区后，测速

root@OpenWrt:/mnt# time dd if=/dev/zero of=./640MB.bin bs=64k count=10000 conv=fsync
10000+0 records in
10000+0 records out
real    0m 14.64s
user    0m 0.02s
sys     0m 12.72s
root@OpenWrt:/mnt# time dd if=./640MB.bin of=/dev/null bs=64k count=10000
10000+0 records in
10000+0 records out
real    0m 8.14s
user    0m 0.02s
sys     0m 7.47s

计算后，写入速度 43.71MB/s 读取速度 78.62MB/s，还算不错！

来源：CSDN

作者：MengXP

链接：https://blog.csdn.net/MengXP/article/details/103935603

标签

nvme

pci