[PATCH v2 1/1] PCI: brcmstb: Use BIT() as __GENMASK() is for internal use only

Andy Shevchenko andriy.shevchenko at linux.intel.com
Mon Nov 15 03:20:00 PST 2021


Use BIT() as __GENMASK() is for internal use only. The rationale
of switching to BIT() is to provide better generated code. The
GENMASK() against non-constant numbers may produce an ugly assembler
code. On contrary the BIT() is simply converted to corresponding shift
operation.

Note, it's the only user of __GENMASK() in the kernel outside of its own realm.

Fixes: 3baec684a531 ("PCI: brcmstb: Accommodate MSI for older chips")
Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
---
v2: switched to BIT() and elaborated why, hence not included tag
 drivers/pci/controller/pcie-brcmstb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 1fc7bd49a7ad..0c49fc65792c 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -619,7 +619,7 @@ static void brcm_msi_remove(struct brcm_pcie *pcie)
 
 static void brcm_msi_set_regs(struct brcm_msi *msi)
 {
-	u32 val = __GENMASK(31, msi->legacy_shift);
+	u32 val = ~(BIT(msi->legacy_shift) - 1);
 
 	writel(val, msi->intr_base + MSI_INT_MASK_CLR);
 	writel(val, msi->intr_base + MSI_INT_CLR);
-- 
2.33.0




More information about the linux-arm-kernel mailing list