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| author | Maciej W. Rozycki <macro@orcam.me.uk> | 2021-07-20 06:27:54 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-08-11 00:31:43 +0300 |
| commit | 1ce849c755342b236fc6236dfe39dbbf536b64b6 (patch) | |
| tree | b9a0c5c7332439f59986bebfc54c9247684c51ca /include/linux/pci_ids.h | |
| parent | fb6a0408eac284688d5262519cbb3be0250e4caf (diff) | |
| download | linux-1ce849c755342b236fc6236dfe39dbbf536b64b6.tar.xz | |
x86/PCI: Add support for the ALi M1487 (IBC) PIRQ router
The ALi M1487 ISA Bus Controller (IBC), a part of the ALi FinALi 486
chipset, implements PCI interrupt steering with a PIRQ router[1] in the
form of four 4-bit mappings, spread across two PCI INTx Routing Table
Mapping Registers, available in the port I/O space accessible indirectly
via the index/data register pair at 0x22/0x23, located at indices 0x42
and 0x43 for the INT1/INT2 and INT3/INT4 lines respectively.
Additionally there is a separate PCI INTx Sensitivity Register at index
0x44 in the same port I/O space, whose bits 3:0 select the trigger mode
for INT[4:1] lines respectively[2]. Manufacturer's documentation says
that this register has to be set consistently with the relevant ELCR
register[3]. Add a router-specific hook then and use it to handle this
register.
Accesses to the port I/O space concerned here need to be unlocked by
writing the value of 0xc5 to the Lock Register at index 0x03
beforehand[4]. Do so then and then lock access after use for safety.
The IBC is implemented as a peer bridge on the host bus rather than a
southbridge on PCI and therefore it does not itself appear in the PCI
configuration space. It is complemented by the M1489 Cache-Memory PCI
Controller (CMP) host-to-PCI bridge, so use that device's identification
for determining the presence of the IBC.
References:
[1] "M1489/M1487: 486 PCI Chip Set", Version 1.2, Acer Laboratories
Inc., July 1997, Section 4: "Configuration Registers", pp. 76-77
[2] same, p. 77
[3] same, Section 5: "M1489/M1487 Software Programming Guide", pp.
99-100
[4] same, Section 4: "Configuration Registers", p. 37
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107191702020.9461@angie.orcam.me.uk
Diffstat (limited to 'include/linux/pci_ids.h')
| -rw-r--r-- | include/linux/pci_ids.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index 4bac1831de80..256fa4d7e86c 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -1121,6 +1121,7 @@ #define PCI_DEVICE_ID_3COM_3CR990SVR 0x990a #define PCI_VENDOR_ID_AL 0x10b9 +#define PCI_DEVICE_ID_AL_M1489 0x1489 #define PCI_DEVICE_ID_AL_M1533 0x1533 #define PCI_DEVICE_ID_AL_M1535 0x1535 #define PCI_DEVICE_ID_AL_M1541 0x1541 |