parisc: Add PDCE_CHECK instruction to HPMC handler

According to the programming note at page 1-31 of the PA 1.1 Firmware
Architecture document, one should use the PDC_INSTR firmware function to
get the instruction that invokes a PDCE_CHECK in the HPMC handler.  This
patch follows this note and sets the instruction which has been a nop up
until now.
Testing on a C3000 and C8000 showed that this firmware call isn't
implemented on those machines, so maybe it's only needed on older ones.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 991654c88eec8635056bef3ae9f536a6e8ff8862..230333157fe384c4171749e2b4eab43e3070a89d 100644 (file)
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -817,7 +817,7 @@ void __init initialize_ivt(const void *iva)
        u32 check = 0;
        u32 *ivap;
        u32 *hpmcp;
-       u32 length;
+       u32 length, instr;
 
        if (strcmp((const char *)iva, "cows can fly"))
                panic("IVT invalid");
@@ -827,6 +827,14 @@ void __init initialize_ivt(const void *iva)
        for (i = 0; i < 8; i++)
            *ivap++ = 0;
 
+       /*
+        * Use PDC_INSTR firmware function to get instruction that invokes
+        * PDCE_CHECK in HPMC handler.  See programming note at page 1-31 of
+        * the PA 1.1 Firmware Architecture document.
+        */
+       if (pdc_instr(&instr) == PDC_OK)
+               ivap[0] = instr;
+
        /* Compute Checksum for HPMC handler */
        length = os_hpmc_size;
        ivap[7] = length;