Re: [PATCH v4 8/8] linux/log2.h: Use roundup/dow_pow_two() on 64bit calculations
From: Nicolas Saenz Julienne <hidden>
Date: 2019-12-12 13:21:08
Also in:
linux-acpi, linux-devicetree, linux-iommu, linux-pci, linux-rdma, linux-rockchip, lkml, netdev
On Thu, 2019-12-05 at 14:38 -0600, Bjorn Helgaas wrote:
The subject contains a couple typos: it's missing "of" and it's missing the "n" on "down".
Noted >
On Tue, Dec 03, 2019 at 12:47:41PM +0100, Nicolas Saenz Julienne wrote:quoted
The function now is safe to use while expecting a 64bit value. Use it where relevant.Please include the function names ("roundup_pow_of_two()", "rounddown_pow_of_two()") in the changelog so it is self-contained and doesn't depend on the subject.
Noted
quoted
Signed-off-by: Nicolas Saenz Julienne <redacted>With the nits above and below addressed, Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci
Thanks!
quoted
--- drivers/acpi/arm64/iort.c | 2 +- drivers/net/ethernet/mellanox/mlx4/en_clock.c | 3 ++- drivers/of/device.c | 3 ++- drivers/pci/controller/cadence/pcie-cadence-ep.c | 3 ++- drivers/pci/controller/cadence/pcie-cadence.c | 3 ++- drivers/pci/controller/pcie-brcmstb.c | 3 ++- drivers/pci/controller/pcie-rockchip-ep.c | 5 +++-- kernel/dma/direct.c | 2 +- 8 files changed, 15 insertions(+), 9 deletions(-)--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c@@ -10,6 +10,7 @@ #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/sizes.h> +#include <linux/log2.h> #include "pcie-cadence.h"@@ -65,7 +66,7 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8fn, * roundup_pow_of_two() returns an unsigned long, which is not suited * for 64bit values. */Please remove the comment above since it no longer applies.
Noted [...]
quoted
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 6af7ae83c4ad..056886c4efec 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c@@ -53,7 +53,7 @@ u64 dma_direct_get_required_mask(struct device *dev) { u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT); - return (1ULL << (fls64(max_dma) - 1)) * 2 - 1; + return rounddown_pow_of_two(max_dma) * 2 - 1;Personally I would probably make this one a separate patch since it's qualitatively different than the others and it would avoid the slight awkwardness of the non-greppable "roundup/down_pow_of_two()" construction in the commit subject. But it's fine either way.
I'll split it into two parts, as RobH made a similar complaint. Regards, Nicolas