内核启动错误：use vmalloc= to increase size.

逻辑部分加了一个PCIE-RC组件，启动时发现如下错误：

vmap allocation for size 268439552 failed: use vmalloc= to increase size.
  xilinx-pcie a0000000.axi-pcie: ioremap failed for resource [mem 0xa0000000-0xafffffff]
  xilinx-pcie a0000000.axi-pcie: Parsing DT failed
  xilinx-pcie: probe of a0000000.axi-pcie failed with error -12

从打印信息来看，是vmalloc 申请失败，原因是申请的空间太大了。

从逻辑组件的设备树可以看到，需要申请256M，而目前实际分配给vmalloc的只有200多M (通过 cat /proc/meminfo查看)。

修改办法：

   修改bootargs的vmalloc大小。（在设备树中修改）

   chosen {
bootargs = "console=ttyPS0,115200 root=/dev/ram rw earlyprintk vmalloc=400M";
linux,stdout-path = "/amba@0/serial@e0000000";
};

修改后，打印如下：

zynq> cat /proc/meminfo
MemTotal:         901364 kB
MemFree:          871852 kB
MemAvailable:     870244 kB
Buffers:             184 kB
Cached:             4696 kB
SwapCached:            0 kB
Active:             3036 kB
Inactive:           2516 kB
Active(anon):        672 kB
Inactive(anon):        0 kB
Active(file):       2364 kB
Inactive(file):     2516 kB
Unevictable:           0 kB
Mlocked:               0 kB
HighTotal:        293888 kB
HighFree:         285408 kB
LowTotal:         607476 kB
LowFree:          586444 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:           672 kB
Mapped:             3268 kB
Shmem:                 0 kB
Slab:               3700 kB
SReclaimable:       1264 kB
SUnreclaim:         2436 kB
KernelStack:         320 kB
PageTables:          104 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:      450680 kB
Committed_AS:       1824 kB
VmallocTotal:     401408 kB
VmallocUsed:       19516 kB
VmallocChunk:     277500 kB
CmaTotal:          16384 kB
CmaFree:           16128 kB