[PATCH 6.9 070/374] usb: xhci: check if requested segments exceeds ERST capacity

Greg Kroah-Hartman
2024-06-06T14:08:46Z

From: Niklas Neronin <niklas.neronin@linux.intel.com>

[ Upstream commit db4460b6ecf07574d580f01cd88054a62607068c ]

Check if requested segments ('segs' or 'ERST_DEFAULT_SEGS') exceeds the
maximum amount ERST supports.

When 'segs' is '0', 'ERST_DEFAULT_SEGS' is used instead. But both values
may not exceed ERST max.

Macro 'ERST_MAX_SEGS' is renamed to 'ERST_DEFAULT_SEGS'. The new name
better represents the macros, which is the number of Event Ring segments
to allocate, when the amount is not specified.

Additionally, rename and change xhci_create_secondary_interrupter()'s
argument 'int num_segs' to 'unsigned int segs'. This makes it the same
as its counter part in xhci_alloc_interrupter().

Fixes: c99b38c41234 ("xhci: add support to allocate several interrupters")
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240429140245.3955523-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/xhci-mem.c | 22 +++++++++++-----------
drivers/usb/host/xhci.h | 6 +++---
2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 69dd866698833..990008aebe8fd 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2269,24 +2269,24 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
}

static struct xhci_interrupter *
-xhci_alloc_interrupter(struct xhci_hcd *xhci, int segs, gfp_t flags)
+xhci_alloc_interrupter(struct xhci_hcd *xhci, unsigned int segs, gfp_t flags)
{
struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
struct xhci_interrupter *ir;
- unsigned int num_segs = segs;
+ unsigned int max_segs;
int ret;

+ if (!segs)
+ segs = ERST_DEFAULT_SEGS;
+
+ max_segs = BIT(HCS_ERST_MAX(xhci->hcs_params2));
+ segs = min(segs, max_segs);
+
ir = kzalloc_node(sizeof(*ir), flags, dev_to_node(dev));
if (!ir)
return NULL;

- /* number of ring segments should be greater than 0 */
- if (segs <= 0)
- num_segs = min_t(unsigned int, 1 << HCS_ERST_MAX(xhci->hcs_params2),
- ERST_MAX_SEGS);
-
- ir->event_ring = xhci_ring_alloc(xhci, num_segs, 1, TYPE_EVENT, 0,
- flags);
+ ir->event_ring = xhci_ring_alloc(xhci, segs, 1, TYPE_EVENT, 0, flags);
if (!ir->event_ring) {
xhci_warn(xhci, "Failed to allocate interrupter event ring\n");
kfree(ir);
@@ -2344,7 +2344,7 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
}

struct xhci_interrupter *
-xhci_create_secondary_interrupter(struct usb_hcd *hcd, int num_seg)
+xhci_create_secondary_interrupter(struct usb_hcd *hcd, unsigned int segs)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
struct xhci_interrupter *ir;
@@ -2354,7 +2354,7 @@ xhci_create_secondary_interrupter(struct usb_hcd *hcd, int num_seg)
if (!xhci->interrupters || xhci->max_interrupters <= 1)
return NULL;

- ir = xhci_alloc_interrupter(xhci, num_seg, GFP_KERNEL);
+ ir = xhci_alloc_interrupter(xhci, segs, GFP_KERNEL);
if (!ir)
return NULL;

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 6f4bf98a62824..31566e82bbd39 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1392,8 +1392,8 @@ struct urb_priv {
struct xhci_td td[] __counted_by(num_tds);
};

-/* Reasonable limit for number of Event Ring segments (spec allows 32k) */
-#define ERST_MAX_SEGS 2
+/* Number of Event Ring segments to allocate, when amount is not specified. (spec allows 32k) */
+#define ERST_DEFAULT_SEGS 2
/* Poll every 60 seconds */
#define POLL_TIMEOUT 60
/* Stop endpoint command timeout (secs) for URB cancellation watchdog timer */
@@ -1833,7 +1833,7 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
void xhci_free_container_ctx(struct xhci_hcd *xhci,
struct xhci_container_ctx *ctx);
struct xhci_interrupter *
-xhci_create_secondary_interrupter(struct usb_hcd *hcd, int num_seg);
+xhci_create_secondary_interrupter(struct usb_hcd *hcd, unsigned int segs);
void xhci_remove_secondary_interrupter(struct usb_hcd
*hcd, struct xhci_interrupter *ir);

--
2.43.0