diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2020-10-25 00:35:21 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-10-28 22:26:27 +0300 |
| commit | 5d5a97133887b2dfd8e2ad0347c3a02cc7aaa0cb (patch) | |
| tree | 8d5dcf503609c3dbd615e5063a002c929d17a547 /drivers/iommu/amd | |
| parent | 341b4a7211b6ba3a7089e1dc09ac4bd576dfb05f (diff) | |
| download | linux-5d5a97133887b2dfd8e2ad0347c3a02cc7aaa0cb.tar.xz | |
x86/ioapic: Generate RTE directly from parent irqchip's MSI message
The I/O-APIC generates an MSI cycle with address/data bits taken from its
Redirection Table Entry in some combination which used to make sense, but
now is just a bunch of bits which get passed through in some seemingly
arbitrary order.
Instead of making IRQ remapping drivers directly frob the I/OA-PIC RTE, let
them just do their job and generate an MSI message. The bit swizzling to
turn that MSI message into the I/O-APIC's RTE is the same in all cases,
since it's a function of the I/O-APIC hardware. The IRQ remappers have no
real need to get involved with that.
The only slight caveat is that the I/OAPIC is interpreting some of those
fields too, and it does want the 'vector' field to be unique to make EOI
work. The AMD IOMMU happens to put its IRTE index in the bits that the
I/O-APIC thinks are the vector field, and accommodates this requirement by
reserving the first 32 indices for the I/O-APIC. The Intel IOMMU doesn't
actually use the bits that the I/O-APIC thinks are the vector field, so it
fills in the 'pin' value there instead.
[ tglx: Replaced the unreadably macro maze with the cleaned up RTE/msi_msg
bitfields and added commentry to explain the mapping magic ]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-22-dwmw2@infradead.org
Diffstat (limited to 'drivers/iommu/amd')
| -rw-r--r-- | drivers/iommu/amd/iommu.c | 12 |
1 files changed, 0 insertions, 12 deletions
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 3d72ec7bbbf8..9744cdbefd88 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -3669,7 +3669,6 @@ static void irq_remapping_prepare_irte(struct amd_ir_data *data, int devid, int index, int sub_handle) { struct irq_2_irte *irte_info = &data->irq_2_irte; - struct IO_APIC_route_entry *entry; struct amd_iommu *iommu = amd_iommu_rlookup_table[devid]; if (!iommu) @@ -3683,17 +3682,6 @@ static void irq_remapping_prepare_irte(struct amd_ir_data *data, switch (info->type) { case X86_IRQ_ALLOC_TYPE_IOAPIC: - /* Setup IOAPIC entry */ - entry = info->ioapic.entry; - info->ioapic.entry = NULL; - memset(entry, 0, sizeof(*entry)); - entry->vector = index; - entry->is_level = info->ioapic.is_level; - entry->active_low = info->ioapic.active_low; - /* Mask level triggered irqs. */ - entry->masked = info->ioapic.is_level; - break; - case X86_IRQ_ALLOC_TYPE_HPET: case X86_IRQ_ALLOC_TYPE_PCI_MSI: case X86_IRQ_ALLOC_TYPE_PCI_MSIX: |