| Message ID | 20211119193732.12343-1-refactormyself@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | PCI/ASPM: Remove struct aspm_latency | expand |
On Fri, Nov 19, 2021 at 08:37:28PM +0100, Saheed O. Bolarinwa wrote: > To validate and set link latency capability, `struct aspm_latency` and > related members defined within `struct pcie_link_state` are used. > However, since there are not many access to theses values, it is > possible to directly access and compute these values. > > Doing this will also reduce the dependency on `struct pcie_link_state`. > > The series removes `struct aspm_latency` and related members within > `struct pcie_link_state`. All latencies are now calculated when needed. > > > VERSION CHANGES: > - v2: > » - directly access downstream by calling `pci_function_0()` > » instead of using the `struct pcie_link_state` > - v3: > » - rebase on Linux 5.15-rc2 > - v4 > » - Create a seprate path to move pci_function_0() upward > - v5 > - shorten long lines as noted in the review > > MERGE NOTICE: > These series are based on > » 'commit fa55b7dcdc43 ("Linux 5.16-rc1")' > > Reviewed-by: Christoph Hellwig <hch@lst.de> > > Bolarinwa O. Saheed (1): > PCI/ASPM: Move pci_function_0() upward > > Saheed O. Bolarinwa (3): > PCI/ASPM: Do not cache link latencies > PCI/ASPM: Remove struct pcie_link_state.acceptable > PCI/ASPM: Remove struct aspm_latency > > drivers/pci/pcie/aspm.c | 95 +++++++++++++++++++---------------------- > 1 file changed, 44 insertions(+), 51 deletions(-) Applied to pci/aspm for v5.17, thanks very much! We're chipping away at the cruft in aspm.c little by little. I made the following changes. Some whitespace; the rest to take advantage of the fact that Device Capabilities is read-only and Amey added a cache of it with 691392448065 ("PCI: Cache PCIe Device Capabilities register") That commit uses FIELD_GET(), which is kind of slick and might be useful in aspm.c as well. diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index e29611080a90..c6d2e76e0502 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -378,7 +378,7 @@ static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value) static void pcie_aspm_check_latency(struct pci_dev *endpoint) { - u32 reg32, latency, encoding, lnkcap_up, lnkcap_dw; + u32 latency, encoding, lnkcap_up, lnkcap_dw; u32 l1_switch_latency = 0, latency_up_l0s; u32 latency_up_l1, latency_dw_l0s, latency_dw_l1; u32 acceptable_l0s, acceptable_l1; @@ -390,24 +390,22 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint) return; link = endpoint->bus->self->link_state; - pcie_capability_read_dword(endpoint, PCI_EXP_DEVCAP, ®32); + /* Calculate endpoint L0s acceptable latency */ - encoding = (reg32 & PCI_EXP_DEVCAP_L0S) >> 6; + encoding = (endpoint->devcap & PCI_EXP_DEVCAP_L0S) >> 6; acceptable_l0s = calc_l0s_acceptable(encoding); + /* Calculate endpoint L1 acceptable latency */ - encoding = (reg32 & PCI_EXP_DEVCAP_L1) >> 9; + encoding = (endpoint->devcap & PCI_EXP_DEVCAP_L1) >> 9; acceptable_l1 = calc_l1_acceptable(encoding); while (link) { - struct pci_dev *dev = pci_function_0( - link->pdev->subordinate); + struct pci_dev *dev = pci_function_0(link->pdev->subordinate); /* Read direction exit latencies */ - pcie_capability_read_dword(link->pdev, - PCI_EXP_LNKCAP, + pcie_capability_read_dword(link->pdev, PCI_EXP_LNKCAP, &lnkcap_up); - pcie_capability_read_dword(dev, - PCI_EXP_LNKCAP, + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap_dw); latency_up_l0s = calc_l0s_latency(lnkcap_up); latency_up_l1 = calc_l1_latency(lnkcap_up);
To validate and set link latency capability, `struct aspm_latency` and related members defined within `struct pcie_link_state` are used. However, since there are not many access to theses values, it is possible to directly access and compute these values. Doing this will also reduce the dependency on `struct pcie_link_state`. The series removes `struct aspm_latency` and related members within `struct pcie_link_state`. All latencies are now calculated when needed. VERSION CHANGES: - v2: » - directly access downstream by calling `pci_function_0()` » instead of using the `struct pcie_link_state` - v3: » - rebase on Linux 5.15-rc2 - v4 » - Create a seprate path to move pci_function_0() upward - v5 - shorten long lines as noted in the review MERGE NOTICE: These series are based on » 'commit fa55b7dcdc43 ("Linux 5.16-rc1")' Reviewed-by: Christoph Hellwig <hch@lst.de> Bolarinwa O. Saheed (1): PCI/ASPM: Move pci_function_0() upward Saheed O. Bolarinwa (3): PCI/ASPM: Do not cache link latencies PCI/ASPM: Remove struct pcie_link_state.acceptable PCI/ASPM: Remove struct aspm_latency drivers/pci/pcie/aspm.c | 95 +++++++++++++++++++---------------------- 1 file changed, 44 insertions(+), 51 deletions(-)