On 2021-11-15 11:20, Andy Shevchenko wrote:
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.
FWIW, If you care about code quality and want the compiler to do the
obvious thing, why not specify it as the obvious thing:
u32 val = ~0 << msi->legacy_shift;
Personally I don't think that abusing BIT() in the context of setting
multiple bits is any better than abusing __GENMASK()...
Robin.
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@xxxxxxxxxxxxxxx>
---
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);
