parisc: hijack jump to start_kernel

Bang in our own start_parisc call, which initializes the PDC
width, and turns on the FPU.

Previously, if CONFIG_PRINTK_TIME was on, we'd attempt to use
the FPU before we had enabled it, resulting in a difficult
to diagnose panic.

This patch causes init_per_cpu to redundantly set these for
cpu0, but this is harmless.

diff --git a/arch/parisc/kernel/head.S b/arch/parisc/kernel/head.S
index a84e31e828768943a7ac288ccb26aa49499b275c..0e3d9f9b9e33e97680190e3752cea063fce9c251 100644 (file)
--- a/arch/parisc/kernel/head.S
+++ b/arch/parisc/kernel/head.S
@@ -121,7 +121,7 @@ $pgt_fill_loop:
        copy            %r0,%r2
 
        /* And the RFI Target address too */
-       load32          start_kernel,%r11
+       load32          start_parisc,%r11
 
        /* And the initial task pointer */
        load32          init_thread_union,%r6

diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index 39e7c5a5946a8981deee1afa1296efc7cff9eadc..a59b71efdbe56215ab297b6ad65c9c45ada3ae3c 100644 (file)
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -368,6 +368,31 @@ static int __init parisc_init(void)
 
        return 0;
 }
-
 arch_initcall(parisc_init);
 
+void start_parisc(void)
+{
+       extern void start_kernel(void);
+
+       int ret, cpunum;
+       struct pdc_coproc_cfg coproc_cfg;
+
+       cpunum = smp_processor_id();
+
+       set_firmware_width_unlocked();
+
+       ret = pdc_coproc_cfg_unlocked(&coproc_cfg);
+       if (ret >= 0 && coproc_cfg.ccr_functional) {
+               mtctl(coproc_cfg.ccr_functional, 10);
+
+               cpu_data[cpunum].fp_rev = coproc_cfg.revision;
+               cpu_data[cpunum].fp_model = coproc_cfg.model;
+
+               asm volatile ("fstd     %fr0,8(%sp)");
+       } else {
+               panic("must have an fpu to boot linux");
+       }
+
+       start_kernel();
+       // not reached
+}