[SRU] [I/Unstable/OEM-5.13] [PATCH 4/7] thunderbolt: Add vendor specific NHI quirk for auto-clearing interrupt status
Kai-Heng Feng
kai.heng.feng at canonical.com
Wed Aug 25 05:23:32 UTC 2021
From: Sanjay R Mehta <sanju.mehta at amd.com>
BugLink: https://bugs.launchpad.net/bugs/1941036
Introduce nhi_check_quirks() routine to handle any vendor specific quirks
to manage a hardware specific implementation.
On Intel hardware the USB4 controller supports clearing the interrupt
status register automatically right after it is being issued. For this
reason add a new quirk that does that on all Intel hardware.
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar at amd.com>
Signed-off-by: Sanjay R Mehta <sanju.mehta at amd.com>
Signed-off-by: Mika Westerberg <mika.westerberg at linux.intel.com>
(cherry picked from commit e390909ac763589558ffb91856f121820f933e4b linux-next)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
drivers/thunderbolt/nhi.c | 33 +++++++++++++++++++++++++--------
include/linux/thunderbolt.h | 2 ++
2 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index bfb780601e292..c044a64420752 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -36,6 +36,8 @@
#define NHI_MAILBOX_TIMEOUT 500 /* ms */
+#define QUIRK_AUTO_CLEAR_INT BIT(0)
+
static int ring_interrupt_index(struct tb_ring *ring)
{
int bit = ring->hop;
@@ -67,14 +69,17 @@ static void ring_interrupt_active(struct tb_ring *ring, bool active)
else
index = ring->hop + ring->nhi->hop_count;
- /*
- * Ask the hardware to clear interrupt status bits automatically
- * since we already know which interrupt was triggered.
- */
- misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
- if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
- misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
- iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
+ if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT) {
+ /*
+ * Ask the hardware to clear interrupt status
+ * bits automatically since we already know
+ * which interrupt was triggered.
+ */
+ misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
+ if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
+ misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
+ iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
+ }
}
ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
@@ -1075,6 +1080,16 @@ static void nhi_shutdown(struct tb_nhi *nhi)
nhi->ops->shutdown(nhi);
}
+static void nhi_check_quirks(struct tb_nhi *nhi)
+{
+ /*
+ * Intel hardware supports auto clear of the interrupt status
+ * reqister right after interrupt is being issued.
+ */
+ if (nhi->pdev->vendor == PCI_VENDOR_ID_INTEL)
+ nhi->quirks |= QUIRK_AUTO_CLEAR_INT;
+}
+
static int nhi_init_msi(struct tb_nhi *nhi)
{
struct pci_dev *pdev = nhi->pdev;
@@ -1254,6 +1269,8 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (!nhi->tx_rings || !nhi->rx_rings)
return -ENOMEM;
+ nhi_check_quirks(nhi);
+
res = nhi_init_msi(nhi);
if (res) {
dev_err(&pdev->dev, "cannot enable MSI, aborting\n");
diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
index e7c96c37174f1..124e13cb1469c 100644
--- a/include/linux/thunderbolt.h
+++ b/include/linux/thunderbolt.h
@@ -468,6 +468,7 @@ static inline struct tb_xdomain *tb_service_parent(struct tb_service *svc)
* @interrupt_work: Work scheduled to handle ring interrupt when no
* MSI-X is used.
* @hop_count: Number of rings (end point hops) supported by NHI.
+ * @quirks: NHI specific quirks if any
*/
struct tb_nhi {
spinlock_t lock;
@@ -480,6 +481,7 @@ struct tb_nhi {
bool going_away;
struct work_struct interrupt_work;
u32 hop_count;
+ unsigned long quirks;
};
/**
--
2.32.0
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