From: Bjorn Helgaas <helgaas@kernel.org>
To: Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
Vinod Koul <vkoul@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
dmaengine@vger.kernel.org
Subject: Re: [PATCH 04/15] PCI: Add pci_find_vsec_capability() to find a specific VSEC
Date: Mon, 1 Feb 2021 16:39:20 -0600 [thread overview]
Message-ID: <20210201223920.GA46282@bjorn-Precision-5520> (raw)
In-Reply-To: <cc4b62f333342df8e029b175079203cfe2bd095c.1608053262.git.gustavo.pimentel@synopsys.com>
[+cc Vinod, Dan, dmaengine]
On Tue, Dec 15, 2020 at 06:30:13PM +0100, Gustavo Pimentel wrote:
> Add pci_find_vsec_capability() that crawls through the device config
> space searching in all Vendor-Specific Extended Capabilities for a
> particular capability ID.
>
> Vendor-Specific Extended Capability (VSEC) is a PCIe capability (acts
> like a wrapper) specified by PCI-SIG that allows the vendor to create
> their own and specific capability in the device config space.
>
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
If you fix the below, feel free to add my
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Otherwise, I can take it myself. But that will be an ordering issue
in the merge window if you merge the rest of the series via another
tree.
> ---
> drivers/pci/pci.c | 29 +++++++++++++++++++++++++++++
> include/linux/pci.h | 1 +
> include/uapi/linux/pci_regs.h | 5 +++++
> 3 files changed, 35 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 6d4d5a2..235d0b2 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -623,6 +623,35 @@ u64 pci_get_dsn(struct pci_dev *dev)
> }
> EXPORT_SYMBOL_GPL(pci_get_dsn);
>
> +/**
> + * pci_find_vsec_capability - Find a vendor-specific extended capability
> + * @dev: PCI device to query
> + * @cap: vendor-specific capability id code
s/id/ID/
> + *
> + * Returns the address of the vendor-specific structure that matches the
> + * requested capability id code within the device's PCI configuration space
s/id/ID/
> + * or 0 if it does not find a match.
> + */
> +int pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id)
> +{
> + u32 header;
> + int vsec;
int vsec;
u32 header;
since that's the order they're used.
> +
> + vsec = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VNDR);
> + while (vsec) {
> + if (pci_read_config_dword(dev, vsec + 0x4,
s/0x4/PCI_VSEC_HDR/
> + &header) == PCIBIOS_SUCCESSFUL &&
> + PCI_VSEC_CAP_ID(header) == vsec_cap_id)
> + break;
return vsec;
> +
> + vsec = pci_find_next_ext_capability(dev, vsec,
> + PCI_EXT_CAP_ID_VNDR);
> + }
> +
> + return vsec;
return 0;
> +}
> +EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
> +
> static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
> {
> int rc, ttl = PCI_FIND_CAP_TTL;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 22207a7..effecb0 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1067,6 +1067,7 @@ int pci_find_capability(struct pci_dev *dev, int cap);
> int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);
> int pci_find_ext_capability(struct pci_dev *dev, int cap);
> int pci_find_next_ext_capability(struct pci_dev *dev, int pos, int cap);
> +int pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id);
> int pci_find_ht_capability(struct pci_dev *dev, int ht_cap);
> int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap);
> struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index a95d55f..f5d17be 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -730,6 +730,11 @@
> #define PCI_EXT_CAP_DSN_SIZEOF 12
> #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40
>
> +/* Vendor-Specific Extended Capabilities */
> +#define PCI_VSEC_CAP_ID(header) (header & 0x0000ffff)
> +#define PCI_VSEC_CAP_REV(header) ((header >> 16) & 0xf)
> +#define PCI_VSEC_CAP_LEN(header) ((header >> 20) & 0xffc)
Please put these next to the existing PCI_VSEC_HDR.
Why does PCI_VSEC_CAP_LEN mask with 0xffc instead of 0xfff? I don't
see anything in the spec about VSEC Length having to be a multiple of
4 (PCIe r5.0, sec 7.9.5.2).
But you don't use this anyway, so I'd just drop it (and
PCI_VSEC_CAP_REV) altogether.
> /* Advanced Error Reporting */
> #define PCI_ERR_UNCOR_STATUS 4 /* Uncorrectable Error Status */
> #define PCI_ERR_UNC_UND 0x00000001 /* Undefined */
> --
> 2.7.4
>
next prev parent reply other threads:[~2021-02-01 22:40 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 17:30 [PATCH 00/15] dmaengine: dw-edma: HDMA support Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 01/15] dmaengine: dw-edma: Add writeq() and readq() for 64 bits architectures Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 02/15] dmaengine: dw-edma: Fix comments offset characters' alignment Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 03/15] dmaengine: dw-edma: Add support for the HDMA feature Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 04/15] PCI: Add pci_find_vsec_capability() to find a specific VSEC Gustavo Pimentel
2021-02-01 22:39 ` Bjorn Helgaas [this message]
2021-02-01 23:24 ` Dan Williams
2021-02-01 23:29 ` Ben Widawsky
2021-02-02 12:25 ` Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 05/15] dmaengine: dw-edma: Add PCIe VSEC data retrieval support Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 06/15] dmaengine: dw-edma: Add device_prep_interleave_dma() support Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 07/15] dmaengine: dw-edma: Improve number of channels check Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 08/15] dmaengine: dw-edma: Reorder variables to keep consistency Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 09/15] dmaengine: dw-edma: Improve the linked list and data blocks definition Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 10/15] dmaengine: dw-edma: Change linked list and data blocks offset and sizes Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 11/15] dmaengine: dw-edma: Move struct dentry variable from static definition into dw_edma struct Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 12/15] dmaengine: dw-edma: Fix crash on loading/unloading driver Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 13/15] dmaengine: dw-edma: Change DMA abreviation from lower into upper case Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 14/15] dmaengine: dw-edma: Revert fix scatter-gather address calculation Gustavo Pimentel
2020-12-15 17:30 ` [PATCH 15/15] dmaengine: dw-edma: Add pcim_iomap_table return checker Gustavo Pimentel
2021-02-01 7:16 ` [PATCH 00/15] dmaengine: dw-edma: HDMA support Vinod Koul
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