[PATCH 0/2] GICv3 ITS fixes for v4.3

[PATCH 0/2] GICv3 ITS fixes for v4.3

[Marc Zyngier]

Thomas, Jason,

A couple of relatively minor fixes for the GICv3 ITS code:
- Silence a warning that seems to happen when GCC is a bit inlining happy,
- Fix a thinko when trying to account for PCI aliases.

Thanks,

	M.

Marc Zyngier (2):
  irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets
    inlined
  irqchip/gic-v3-its: Count additional LPIs for the aliased devices

 drivers/irqchip/irq-gic-v3-its-pci-msi.c | 2 +-
 drivers/irqchip/irq-gic-v3-its.c         | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

-- 
2.1.4

[PATCH 1/2] irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined

[Marc Zyngier]

More agressive inlining in recent versions of GCC have uncovered
a new set of warnings:

	drivers/irqchip/irq-gic-v3-its.c: In function its_msi_prepare:
	drivers/irqchip/irq-gic-v3-its.c:1148:26: warning: lpi_base may be used
	uninitialized in this function [-Wmaybe-uninitialized]
	  dev->event_map.lpi_base = lpi_base;
                          ^
	drivers/irqchip/irq-gic-v3-its.c:1116:6: note: lpi_base was declared here
	  int lpi_base;
	      ^
	drivers/irqchip/irq-gic-v3-its.c:1149:25: warning: nr_lpis may be used
	uninitialized in this function [-Wmaybe-uninitialized]
	  dev->event_map.nr_lpis = nr_lpis;
	                         ^
	drivers/irqchip/irq-gic-v3-its.c:1117:6: note: nr_lpis was declared here
	  int nr_lpis;
	      ^
The warning is fairly benign (there is no code path that could
actually use uninitialized vatiables), but let's silence it anyway
by zeroing the variables on the error path.

Reported-by: Alex Shi <alex.shi@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ac7ae2b..25ceae9f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -719,6 +719,9 @@ static unsigned long *its_lpi_alloc_chunks(int nr_irqs, int *base, int *nr_ids)
 out:
 	spin_unlock(&lpi_lock);
 
+	if (!bitmap)
+		*base = *nr_ids = 0;
+
 	return bitmap;
 }
 
-- 
2.1.4

[PATCH 2/2] irqchip/gic-v3-its: Count additional LPIs for the aliased devices

[Marc Zyngier]

When configuring the interrupt mapping for a new device, we
iterate over all the possible aliases to account for their
maximum MSI allocation. This was introduced by e8137f4f5088
("irqchip: gicv3-its: Iterate over PCI aliases to generate ITS configuration").

Turns out that the code doing that is a bit braindead, and repeatedly
accounts for the same device over and over.

Fix this by counting the actual alias that is passed to us by the
core code.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/irqchip/irq-gic-v3-its-pci-msi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index cf351c6..a7c8c9f 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -62,7 +62,7 @@ static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
 
 	dev_alias->dev_id = alias;
 	if (pdev != dev_alias->pdev)
-		dev_alias->count += its_pci_msi_vec_count(dev_alias->pdev);
+		dev_alias->count += its_pci_msi_vec_count(pdev);
 
 	return 0;
 }
-- 
2.1.4