[PATCH v1 1/1] IB/hfi1: Don't cast parameter in bit operations

From: Andy Shevchenko
Date: Wed Feb 23 2022 - 13:54:13 EST


While in this particular case it would not be a (critical) issue,
the pattern itself is bad and error prone in case somebody blindly
copies to their code.

Don't cast parameter to unsigned long pointer in the bit operations.
Instead copy to a local variable on stack of a proper type and use.

Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/infiniband/hw/hfi1/chip.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index f1245c94ae26..100274b926d3 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -8286,34 +8286,33 @@ static void is_interrupt(struct hfi1_devdata *dd, unsigned int source)
irqreturn_t general_interrupt(int irq, void *data)
{
struct hfi1_devdata *dd = data;
- u64 regs[CCE_NUM_INT_CSRS];
+ DECLARE_BITMAP(pending, CCE_NUM_INT_CSRS * 64);
+ u64 value;
u32 bit;
int i;
- irqreturn_t handled = IRQ_NONE;

this_cpu_inc(*dd->int_counter);

/* phase 1: scan and clear all handled interrupts */
for (i = 0; i < CCE_NUM_INT_CSRS; i++) {
- if (dd->gi_mask[i] == 0) {
- regs[i] = 0; /* used later */
- continue;
- }
- regs[i] = read_csr(dd, CCE_INT_STATUS + (8 * i)) &
- dd->gi_mask[i];
+ if (dd->gi_mask[i] == 0)
+ value = 0; /* used later */
+ else
+ value = read_csr(dd, CCE_INT_STATUS + (8 * i)) & dd->gi_mask[i];
+
+ /* save for further use */
+ bitmap_from_u64(&pending[BITS_TO_LONGS(i * 64)], value);
+
/* only clear if anything is set */
- if (regs[i])
- write_csr(dd, CCE_INT_CLEAR + (8 * i), regs[i]);
+ if (value)
+ write_csr(dd, CCE_INT_CLEAR + (8 * i), value);
}

/* phase 2: call the appropriate handler */
- for_each_set_bit(bit, (unsigned long *)&regs[0],
- CCE_NUM_INT_CSRS * 64) {
+ for_each_set_bit(bit, pending, CCE_NUM_INT_CSRS * 64)
is_interrupt(dd, bit);
- handled = IRQ_HANDLED;
- }

- return handled;
+ return IRQ_RETVAL(!bitmap_empty(pending, CCE_NUM_INT_CSRS * 64));
}

irqreturn_t sdma_interrupt(int irq, void *data)
--
2.34.1