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| author | Marek Behún <kabel@kernel.org> | 2021-10-28 20:56:53 +0200 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2021-10-29 10:25:31 +0100 |
| commit | 7a41ae80bdcb17e14dd7d83239b8a0cf368f18be (patch) | |
| tree | 3b9c4d9144556f0574f11cc0c1e9dcfe62c46b06 | |
| parent | 2b650b7ff20eb7ea8ef9031d20fb657286ab90cc (diff) | |
| download | linux-stable-7a41ae80bdcb17e14dd7d83239b8a0cf368f18be.tar.gz linux-stable-7a41ae80bdcb17e14dd7d83239b8a0cf368f18be.tar.bz2 linux-stable-7a41ae80bdcb17e14dd7d83239b8a0cf368f18be.zip | |
PCI: pci-bridge-emul: Fix emulation of W1C bits
The pci_bridge_emul_conf_write() function correctly clears W1C bits in
cfgspace cache, but it does not inform the underlying implementation
about the clear request: the .write_op() method is given the value with
these bits cleared.
This is wrong if the .write_op() needs to know which bits were requested
to be cleared.
Fix the value to be passed into the .write_op() method to have requested
W1C bits set, so that it can clear them.
Both pci-bridge-emul users (mvebu and aardvark) are compatible with this
change.
Link: https://lore.kernel.org/r/20211028185659.20329-2-kabel@kernel.org
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Cc: Russell King <rmk+kernel@armlinux.org.uk>
| -rw-r--r-- | drivers/pci/pci-bridge-emul.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c index fdaf86a888b7..db97cddfc85e 100644 --- a/drivers/pci/pci-bridge-emul.c +++ b/drivers/pci/pci-bridge-emul.c @@ -431,8 +431,21 @@ int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where, /* Clear the W1C bits */ new &= ~((value << shift) & (behavior[reg / 4].w1c & mask)); + /* Save the new value with the cleared W1C bits into the cfgspace */ cfgspace[reg / 4] = cpu_to_le32(new); + /* + * Clear the W1C bits not specified by the write mask, so that the + * write_op() does not clear them. + */ + new &= ~(behavior[reg / 4].w1c & ~mask); + + /* + * Set the W1C bits specified by the write mask, so that write_op() + * knows about that they are to be cleared. + */ + new |= (value << shift) & (behavior[reg / 4].w1c & mask); + if (write_op) write_op(bridge, reg, old, new, mask); |