This is a note to let you know that I've just added the patch titled
PCI: apple: Initialize pcie->nvecs before use
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-apple-initialize-pcie-nvecs-before-use.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit de7d4d97a6cb910b0f4b589217535888db4e9c1d
Author: Sven Peter <sven@xxxxxxxxxxxxx>
Date: Sat Mar 11 14:34:53 2023 +0100
PCI: apple: Initialize pcie->nvecs before use
[ Upstream commit d8650c0c2aa2e413594e4cb0faafa9958c1d7782 ]
The apple_pcie_setup_port() function computes ilog2(pcie->nvecs) to set
up the number of MSIs available for each port. However, it's called
before apple_msi_init(), which initializes pcie->nvecs.
Luckily, pcie->nvecs is part of kzalloc()-ed structure and, as such,
initialized as zero. ilog2(0) happens to be 0xffffffff which then simply
configures more MSIs in hardware than we have. This doesn't break
anything because we never hand out those vectors.
Thus, swap the order of the two calls so that the correctly initialized
value is then used.
[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20230311133453.63246-1-sven@xxxxxxxxxxxxx
Fixes: 476c41ed4597 ("PCI: apple: Implement MSI support")
Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Reviewed-by: Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>
Reviewed-by: Eric Curtin <ecurtin@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index 66f37e403a09c..2340dab6cd5bd 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -783,6 +783,10 @@ static int apple_pcie_init(struct pci_config_window *cfg)
cfg->priv = pcie;
INIT_LIST_HEAD(&pcie->ports);
+ ret = apple_msi_init(pcie);
+ if (ret)
+ return ret;
+
for_each_child_of_node(dev->of_node, of_port) {
ret = apple_pcie_setup_port(pcie, of_port);
if (ret) {
@@ -792,7 +796,7 @@ static int apple_pcie_init(struct pci_config_window *cfg)
}
}
- return apple_msi_init(pcie);
+ return 0;
}
static int apple_pcie_probe(struct platform_device *pdev)
