path: root/arch
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authorHelge Deller <deller@gmx.de>2019-04-02 12:13:27 +0200
committerHelge Deller <deller@gmx.de>2019-04-06 19:07:55 +0200
commitd006e95b5561f708d0385e9677ffe2c46f2ae345 (patch)
tree8cf2b12a8846a6b2f6ca825328e26413e8fd8c00 /arch
parentf324fa58327791b2696628b31480e7e21c745706 (diff)
parisc: Detect QEMU earlier in boot process
While adding LASI support to QEMU, I noticed that the QEMU detection in the kernel happens much too late. For example, when a LASI chip is found by the kernel, it registers the LASI LED driver as well. But when we run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so we need to access the running_on_QEMU flag earlier than before. This patch now makes the QEMU detection the fist task of the Linux kernel by moving it to where the kernel enters the C-coding. Fixes: 310d82784fb4 ("parisc: qemu idle sleep support") Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v4.14+
Diffstat (limited to 'arch')
2 files changed, 3 insertions, 6 deletions
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index eb39e7e380d7..841db71958cd 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -210,12 +210,6 @@ void __cpuidle arch_cpu_idle(void)
static int __init parisc_idle_init(void)
- const char *marker;
- /* check QEMU/SeaBIOS marker in PAGE0 */
- marker = (char *) &PAGE0->pad0;
- running_on_qemu = (memcmp(marker, "SeaBIOS", 8) == 0);
if (!running_on_qemu)
diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index 15dd9e21be7e..d908058d05c1 100644
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -397,6 +397,9 @@ void __init start_parisc(void)
int ret, cpunum;
struct pdc_coproc_cfg coproc_cfg;
+ /* check QEMU/SeaBIOS marker in PAGE0 */
+ running_on_qemu = (memcmp(&PAGE0->pad0, "SeaBIOS", 8) == 0);
cpunum = smp_processor_id();