Re: [PATCH v2 4/8] powerpc/xive: Simplify xive_core_debug_show()

On 3/9/21 10:42 AM, Greg Kurz wrote:

On Tue, 9 Mar 2021 10:13:39 +0100
Greg Kurz [off-list ref] wrote:

quoted

On Mon, 8 Mar 2021 19:11:11 +0100
Cédric Le Goater [off-list ref] wrote:

quoted

On 3/8/21 7:07 PM, Greg Kurz wrote:

quoted

On Wed, 3 Mar 2021 18:48:53 +0100
Cédric Le Goater [off-list ref] wrote:

quoted

Now that the IPI interrupt has its own domain, the checks on the HW
interrupt number XIVE_IPI_HW_IRQ and on the chip can be replaced by a
check on the domain.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---

Shouldn't this have the following tags ?

Reported-by: kernel test robot <redacted>
Reported-by: Dan Carpenter <redacted>
Fixes: 930914b7d528 ("powerpc/xive: Add a debugfs file to dump internal XIVE state")

The next patch has because it removes the useless check on irq_data.
 

Ok I get it. This report isn't about an actual crash. Just a false
positive because of the not needed check in the caller.

Hrm... I meant because of the check in xive_debug_show_irq(). On the
contrary, the check removed by this patch in xive_core_debug_show()
was rather an explicit hint that xive_debug_show_irq() couldn't be
called with d being NULL.

yes. irq_desc_get_irq_data() does not return a NULL value and 
xive_debug_show_irq() is only called from the for_each_irq_desc()
loop. 


C.

quoted

quoted

C.

quoted

Anyway,

Reviewed-by: Greg Kurz <redacted>

quoted

 arch/powerpc/sysdev/xive/common.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 678680531d26..7581cb12bb53 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c

@@ -1579,17 +1579,14 @@ static void xive_debug_show_cpu(struct seq_file *m, int cpu)
 	seq_puts(m, "\n");
 }
 
-static void xive_debug_show_irq(struct seq_file *m, u32 hw_irq, struct irq_data *d)
+static void xive_debug_show_irq(struct seq_file *m, struct irq_data *d)
 {
-	struct irq_chip *chip = irq_data_get_irq_chip(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
 	int rc;
 	u32 target;
 	u8 prio;
 	u32 lirq;
 
-	if (!is_xive_irq(chip))
-		return;
-
 	rc = xive_ops->get_irq_config(hw_irq, &target, &prio, &lirq);
 	if (rc) {
 		seq_printf(m, "IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);

@@ -1627,16 +1624,9 @@ static int xive_core_debug_show(struct seq_file *m, void *private)
 
 	for_each_irq_desc(i, desc) {
 		struct irq_data *d = irq_desc_get_irq_data(desc);
-		unsigned int hw_irq;
-
-		if (!d)
-			continue;
-
-		hw_irq = (unsigned int)irqd_to_hwirq(d);
 
-		/* IPIs are special (HW number 0) */
-		if (hw_irq != XIVE_IPI_HW_IRQ)
-			xive_debug_show_irq(m, hw_irq, d);
+		if (d->domain == xive_irq_domain)
+			xive_debug_show_irq(m, d);
 	}
 	return 0;
 }