[RFC PATCH v2 01/22] xhci: fix event ring segment table related masks and variables in header

From: Wesley Cheng
Date: Wed Jan 25 2023 - 22:16:43 EST


From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

xHC controller can supports up to 1024 interrupters.
To fit these change the max_interrupters varable from u8 to u16.

Add a separate mask for the reserve and preserve bits [5:0] in the erst
base register and use it instead of the ERST_PRT_MASK.
ERSR_PTR_MASK [3:0] is intended for masking bits in the
event ring dequeue pointer register.

Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-mem.c | 4 ++--
drivers/usb/host/xhci.h | 5 ++++-
2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 81ca2bc1f0be..679befa97c7a 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2529,8 +2529,8 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
"// Set ERST base address for ir_set 0 = 0x%llx",
(unsigned long long)xhci->erst.erst_dma_addr);
val_64 = xhci_read_64(xhci, &xhci->ir_set->erst_base);
- val_64 &= ERST_PTR_MASK;
- val_64 |= (xhci->erst.erst_dma_addr & (u64) ~ERST_PTR_MASK);
+ val_64 &= ERST_BASE_RSVDP;
+ val_64 |= (xhci->erst.erst_dma_addr & (u64) ~ERST_BASE_RSVDP);
xhci_write_64(xhci, val_64, &xhci->ir_set->erst_base);

/* Set the event ring dequeue address */
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index c9f06c5e4e9d..e1362e0c50e1 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -513,6 +513,9 @@ struct xhci_intr_reg {
/* Preserve bits 16:31 of erst_size */
#define ERST_SIZE_MASK (0xffff << 16)

+/* erst_base bitmasks */
+#define ERST_BASE_RSVDP (0x3f)
+
/* erst_dequeue bitmasks */
/* Dequeue ERST Segment Index (DESI) - Segment number (or alias)
* where the current dequeue pointer lies. This is an optional HW hint.
@@ -1773,7 +1776,7 @@ struct xhci_hcd {
u8 sbrn;
u16 hci_version;
u8 max_slots;
- u8 max_interrupters;
+ u16 max_interrupters;
u8 max_ports;
u8 isoc_threshold;
/* imod_interval in ns (I * 250ns) */