Fix an issue with commit 1ce849c75534 ("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.
Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
Cc: Nikolai Zhubr <zhubr.2@xxxxxxxxx>
Fixes: 1ce849c75534 ("x86/PCI: Add support for the ALi M1487 (IBC) PIRQ router")
Cc: stable@xxxxxxxxxxxxxxx # v5.15+
---
New change in v3.
---
arch/x86/pci/irq.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
linux-x86-pirq-router-finali-link.diff
Index: linux-macro/arch/x86/pci/irq.c
===================================================================
--- linux-macro.orig/arch/x86/pci/irq.c
+++ linux-macro/arch/x86/pci/irq.c
@@ -325,6 +325,15 @@ static void write_pc_conf_nybble(u8 base
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)
{
@@ -332,11 +341,13 @@ static int pirq_finali_get(struct pci_de
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;
@@ -350,13 +361,15 @@ static int pirq_finali_set(struct pci_de
};
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;
@@ -365,7 +378,7 @@ static int pirq_finali_set(struct pci_de
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;
