isel (Integer Select) is a new user space instruction in the
PowerISA 2.04 spec. Not all processors implement it so lets emulate
to ensure code built with isel will run everywhere.
---
arch/powerpc/kernel/traps.c | 25 +++++++++++++++++++++++++
1 files changed, 25 insertions(+), 0 deletions(-)
In my git tree for 2.6.25.
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 59c464e..cad6484 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -622,6 +622,9 @@ static void parse_fpe(struct pt_regs *regs)
#define INST_POPCNTB 0x7c0000f4
#define INST_POPCNTB_MASK 0xfc0007fe
+#define INST_ISEL 0x7c00001e
+#define INST_ISEL_MASK 0xfc00003e
+
static int emulate_string_inst(struct pt_regs *regs, u32 instword)
{
u8 rT = (instword >> 21) & 0x1f;
@@ -707,6 +710,23 @@ static int emulate_popcntb_inst(struct pt_regs *regs, u32
instword)
return 0;
}
+static int emulate_isel(struct pt_regs *regs, u32 instword)
+{
+ u8 rT = (instword >> 21) & 0x1f;
+ u8 rA = (instword >> 16) & 0x1f;
+ u8 rB = (instword >> 11) & 0x1f;
+ u8 BC = (instword >> 6) & 0x1f;
+ u8 bit;
+ unsigned long tmp;
+
+ tmp = (rA == 0) ? 0 : regs->gpr[rA];
+ bit = (regs->ccr >> (31 - BC)) & 0x1;
+
+ regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
+
+ return 0;
+}
+
static int emulate_instruction(struct pt_regs *regs)
{
u32 instword;
@@ -749,6 +769,11 @@ static int emulate_instruction(struct pt_regs *regs)
return emulate_popcntb_inst(regs, instword);
}
+ /* Emulate isel (Integer Select) instruction */
+ if ((instword & INST_ISEL_MASK) == INST_ISEL) {
+ return emulate_isel(regs, instword);
+ }
+
return -EINVAL;
}
--
1.5.3.4
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
