When parsing mti,reserved-cpu-vectors we generate a mask of all bits
that have been declared reserved, the loop through starting from bit 2
to find one that isn't reserved (ie. is zero).
This patch accomplishes the same task more simply by:
- Inititialising the reserved mask to 0x3 (ie. the 2 software
interrupts). This means we don't need to skip them later as the loop
previously has.
- Replacing the loop checking for zero bits with find_first_zero_bit,
which fits our needs now that the 2 software interrupts are marked
reserved. This requires that the type of reserved is changed to
unsigned long so that it's suitable for use with bitmap functions.
- Replacing the magic number 8 with the hamming weight of the ST0_IM
field - ie. the number of bits that a MIPS CPU has for interrupt
inputs. This is still a compile-time constant 8, but makes it
clearer why it's 8.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
drivers/irqchip/irq-mips-gic.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 7a42f0b3822f..e4ab65c7056d 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -633,21 +633,21 @@ static const struct irq_domain_ops gic_ipi_domain_ops = {
static int __init gic_of_init(struct device_node *node,
struct device_node *parent)
{
- unsigned int cpu_vec, i, j, reserved, gicconfig, cpu, v[2];
+ unsigned int cpu_vec, i, j, gicconfig, cpu, v[2];
+ unsigned long reserved;
phys_addr_t gic_base;
struct resource res;
size_t gic_len;
/* Find the first available CPU vector. */
- i = reserved = 0;
+ i = 0;
+ reserved = (C_SW0 | C_SW1) >> __fls(C_SW0);
while (!of_property_read_u32_index(node, "mti,reserved-cpu-vectors",
i++, &cpu_vec))
reserved |= BIT(cpu_vec);
- for (cpu_vec = 2; cpu_vec < 8; cpu_vec++) {
- if (!(reserved & BIT(cpu_vec)))
- break;
- }
- if (cpu_vec == 8) {
+
+ cpu_vec = find_first_zero_bit(&reserved, hweight_long(ST0_IM));
+ if (cpu_vec == hweight_long(ST0_IM)) {
pr_err("No CPU vectors available for GIC\n");
return -ENODEV;
}
--
2.14.0
