From: Michal Simek <michal.simek@xilinx.com>
Date: Tue, 9 Sep 2014 07:43:50 +0000 (+0200)
Subject: zynqmp: Do not run Linux SMP on more then 2 cpus on QEMU
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bfcda714d8724ed21bfee4e6553f4cc6025acbfc;p=thirdparty%2Fu-boot.git

zynqmp: Do not run Linux SMP on more then 2 cpus on QEMU

Limit number of cpus in the kernel running on QEMU
to 2 to ensure that stalls are not reported by the kernel.
ZynqMP QEMU is single-threaded and it runs the VCPUs
in round-robin. It takes longer between the CPUs get
to run when more VCPUs are used.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
index 293642058f4..d80457e1d7a 100644
--- a/board/xilinx/zynqmp/zynqmp.c
+++ b/board/xilinx/zynqmp/zynqmp.c
@@ -93,9 +93,14 @@ int board_mmc_init(bd_t *bd)
 }
 #endif
 
+#ifndef CONFIG_LINUX_CMDLINE_SIZE
+# define CONFIG_LINUX_CMDLINE_SIZE	120
+#endif
+
 int board_late_init(void)
 {
 	u32 reg = 0;
+	char args[CONFIG_LINUX_CMDLINE_SIZE];
 	u8 bootmode;
 	u32 ver = zynqmp_get_silicon_version();
 
@@ -107,6 +112,10 @@ int board_late_init(void)
 		break;
 	case ZYNQMP_CSU_VERSION_QEMU:
 	default:
+		strcpy(args, getenv("bootargs"));
+		strncat(args, " maxcpus=2", CONFIG_LINUX_CMDLINE_SIZE);
+		setenv("bootargs", args);
+
 		setenv("serverip", "10.0.2.2");
 		setenv("ipaddr", "10.0.2.15");
 	}