From 1ce849c755342b236fc6236dfe39dbbf536b64b6 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Tue, 20 Jul 2021 05:27:54 +0200 Subject: 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 Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107191702020.9461@angie.orcam.me.uk --- include/linux/pci_ids.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') 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 -- cgit v1.2.3