Commit 4969e223 authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Thomas Gleixner
Browse files

x86/PCI: Fix ALi M1487 (IBC) PIRQ router link value interpretation 



Fix an issue with commit 1ce849c7 ("x86/PCI: Add support for the ALi 
M1487 (IBC) PIRQ router") and correct ALi M1487 (IBC) PIRQ router link 
value (`pirq' cookie) interpretation according to findings in the BIOS.

Credit to Nikolai Zhubr for the detective work as to the bit layout.

Fixes: 1ce849c7 ("x86/PCI: Add support for the ALi M1487 (IBC) PIRQ router")
Signed-off-by: default avatarMaciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2203310013270.44113@angie.orcam.me.uk
parent b584db0c

arch/x86/pci/irq.c

+16 −3
Original line number Diff line number Diff line
@@ -337,6 +337,15 @@ static void write_pc_conf_nybble(u8 base, u8 index, u8 val) 
	pc_conf_set(reg, x);

}



/*

 * FinALi pirq rules are as follows:

 *

 * - bit 0 selects between INTx Routing Table Mapping Registers,

 *

 * - bit 3 selects the nibble within the INTx Routing Table Mapping Register,

 *

 * - bits 7:4 map to bits 3:0 of the PCI INTx Sensitivity Register.

 */

static int pirq_finali_get(struct pci_dev *router, struct pci_dev *dev,

			   int pirq)

{
@@ -344,11 +353,13 @@ static int pirq_finali_get(struct pci_dev *router, struct pci_dev *dev, 
		0, 9, 3, 10, 4, 5, 7, 6, 0, 11, 0, 12, 0, 14, 0, 15

	};

	unsigned long flags;

	u8 index;

	u8 x;



	index = (pirq & 1) << 1 | (pirq & 8) >> 3;

	raw_spin_lock_irqsave(&pc_conf_lock, flags);

	pc_conf_set(PC_CONF_FINALI_LOCK, PC_CONF_FINALI_LOCK_KEY);

	x = irqmap[read_pc_conf_nybble(PC_CONF_FINALI_PCI_INTX_RT1, pirq - 1)];

	x = irqmap[read_pc_conf_nybble(PC_CONF_FINALI_PCI_INTX_RT1, index)];

	pc_conf_set(PC_CONF_FINALI_LOCK, 0);

	raw_spin_unlock_irqrestore(&pc_conf_lock, flags);

	return x;
@@ -362,13 +373,15 @@ static int pirq_finali_set(struct pci_dev *router, struct pci_dev *dev, 
	};

	u8 val = irqmap[irq];

	unsigned long flags;

	u8 index;



	if (!val)

		return 0;



	index = (pirq & 1) << 1 | (pirq & 8) >> 3;

	raw_spin_lock_irqsave(&pc_conf_lock, flags);

	pc_conf_set(PC_CONF_FINALI_LOCK, PC_CONF_FINALI_LOCK_KEY);

	write_pc_conf_nybble(PC_CONF_FINALI_PCI_INTX_RT1, pirq - 1, val);

	write_pc_conf_nybble(PC_CONF_FINALI_PCI_INTX_RT1, index, val);

	pc_conf_set(PC_CONF_FINALI_LOCK, 0);

	raw_spin_unlock_irqrestore(&pc_conf_lock, flags);

	return 1;
@@ -377,7 +390,7 @@ static int pirq_finali_set(struct pci_dev *router, struct pci_dev *dev, 
static int pirq_finali_lvl(struct pci_dev *router, struct pci_dev *dev,

			   int pirq, int irq)

{

	u8 mask = ~(1u << (pirq - 1));

	u8 mask = ~((pirq & 0xf0u) >> 4);

	unsigned long flags;

	u8 trig;