diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2025-11-12 18:14:43 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2025-11-14 15:06:57 -0800 |
| commit | 079115370d00c78ef69b31dd15def90adf2aa579 (patch) | |
| tree | e1e4858d3ede2d62add04710f764eb9985e0df76 /include | |
| parent | f86e51399c2a911a5b01d441de513f17bf773856 (diff) | |
PCI/IDE: Initialize an ID for all IDE streams
The PCIe spec defines two types of streams - selective and link. Each
stream has an ID from the same bucket so a stream ID does not tell the
type. The spec defines an "enable" bit for every stream and required
stream IDs to be unique among all enabled stream but there is no such
requirement for disabled streams.
However, when IDE_KM is programming keys, an IDE-capable device needs
to know the type of stream being programmed to write it directly to
the hardware as keys are relatively large, possibly many of them and
devices often struggle with keeping around rather big data not being
used.
Walk through all streams on a device and initialise the IDs to some
unique number, both link and selective.
The weakest part of this proposal is the host bridge ide_stream_ids_ida.
Technically, a Stream ID only needs to be unique within a given partner
pair. However, with "anonymous" / unassigned streams there is no convenient
place to track the available ids. Proceed with an ida in the host bridge
for now, but consider moving this tracking to be an ide_stream_ids_ida per
device.
Co-developed-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20251113021446.436830-6-dan.j.williams@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pci-ide.h | 6 | ||||
| -rw-r--r-- | include/linux/pci.h | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/pci-ide.h b/include/linux/pci-ide.h index 93194338e4d0..37a1ad9501b0 100644 --- a/include/linux/pci-ide.h +++ b/include/linux/pci-ide.h @@ -97,6 +97,12 @@ struct pci_ide { struct tsm_dev *tsm_dev; }; +/* + * Some devices need help with aliased stream-ids even for idle streams. Use + * this id as the "never enabled" place holder. + */ +#define PCI_IDE_RESERVED_STREAM_ID 255 + void pci_ide_set_nr_streams(struct pci_host_bridge *hb, u16 nr); struct pci_ide_partner *pci_ide_to_settings(struct pci_dev *pdev, struct pci_ide *ide); diff --git a/include/linux/pci.h b/include/linux/pci.h index ba39ca78b382..52a235c61023 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -619,6 +619,7 @@ struct pci_host_bridge { #ifdef CONFIG_PCI_IDE u16 nr_ide_streams; /* Max streams possibly active in @ide_stream_ida */ struct ida ide_stream_ida; + struct ida ide_stream_ids_ida; /* track unique ids per domain */ #endif u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */ int (*map_irq)(const struct pci_dev *, u8, u8); |