[PATCH next v2 5/6] usb: xhci-mtk: Do not use xhci's virt_dev in drop_endpoint

From: Chunfeng Yun
Date: Wed Aug 25 2021 - 22:52:23 EST

xhci-mtk depends on xhci's internal virt_dev when it retrieves its
internal data from usb_host_endpoint both in add_endpoint and
drop_endpoint callbacks. But when setup packet was retired by
transaction errors in xhci_setup_device() path, a virt_dev for the slot
is newly created with real_port 0. This leads to xhci-mtks's NULL pointer
dereference from drop_endpoint callback as xhci-mtk assumes that virt_dev's
real_port is always started from one. The similar problems were addressed
by [1] but that can't cover the failure cases from setup_device.

This patch drops the usages of xhci's virt_dev in xhci-mtk's drop_endpoint
callback by adopting hashtable for searching mtk's schedule entity
from a given usb_host_endpoint pointer instead of searching a linked list.
So mtk's drop_endpoint callback doesn't have to rely on virt_dev at all.

[1] f351f4b63dac ("usb: xhci-mtk: fix oops when unbind driver")

Signed-off-by: Ikjoon Jang <ikjn@xxxxxxxxxxxx>
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
v2: use fixed size hash table instead of rhashtable;
fix some issues as described in this series [2/6]
---
drivers/usb/host/xhci-mtk-sch.c | 100 ++++++++++++++++----------------
drivers/usb/host/xhci-mtk.h | 11 +++-
2 files changed, 60 insertions(+), 51 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 54c521524bfc..f3c6f078f82d 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -80,7 +80,7 @@ decode_ep(struct usb_host_endpoint *ep, enum usb_device_speed speed)
interval /= 1000;
}

- snprintf(buf, DBG_BUF_EN, "%s ep%d%s %s, mpkt:%d, interval:%d/%d%s\n",
+ snprintf(buf, DBG_BUF_EN, "%s ep%d%s %s, mpkt:%d, interval:%d/%d%s",
usb_speed_string(speed), usb_endpoint_num(epd),
usb_endpoint_dir_in(epd) ? "in" : "out",
usb_ep_type_string(usb_endpoint_type(epd)),
@@ -129,6 +129,10 @@ get_bw_info(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
int bw_index;

virt_dev = xhci->devs[udev->slot_id];
+ if (!virt_dev->real_port) {
+ WARN_ONCE(1, "%s invalid real_port\n", dev_name(&udev->dev));
+ return NULL;
+ }

if (udev->speed >= USB_SPEED_SUPER) {
if (usb_endpoint_dir_out(&ep->desc))
@@ -236,14 +240,20 @@ static void drop_tt(struct usb_device *udev)
}
}

-static struct mu3h_sch_ep_info *create_sch_ep(struct usb_device *udev,
- struct usb_host_endpoint *ep, struct xhci_ep_ctx *ep_ctx)
+static struct mu3h_sch_ep_info *
+create_sch_ep(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
+ struct usb_host_endpoint *ep, struct xhci_ep_ctx *ep_ctx)
{
struct mu3h_sch_ep_info *sch_ep;
+ struct mu3h_sch_bw_info *bw_info;
struct mu3h_sch_tt *tt = NULL;
u32 len_bw_budget_table;
size_t mem_size;

+ bw_info = get_bw_info(mtk, udev, ep);
+ if (!bw_info)
+ return ERR_PTR(-ENODEV);
+
if (is_fs_or_ls(udev->speed))
len_bw_budget_table = TT_MICROFRAMES_MAX;
else if ((udev->speed >= USB_SPEED_SUPER)
@@ -266,11 +276,13 @@ static struct mu3h_sch_ep_info *create_sch_ep(struct usb_device *udev,
}
}

+ sch_ep->bw_info = bw_info;
sch_ep->sch_tt = tt;
sch_ep->ep = ep;
sch_ep->speed = udev->speed;
INIT_LIST_HEAD(&sch_ep->endpoint);
INIT_LIST_HEAD(&sch_ep->tt_endpoint);
+ INIT_HLIST_NODE(&sch_ep->hentry);

return sch_ep;
}
@@ -576,9 +588,9 @@ static u32 get_esit_boundary(struct mu3h_sch_ep_info *sch_ep)
return boundary;
}

-static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
- struct mu3h_sch_ep_info *sch_ep)
+static int check_sch_bw(struct mu3h_sch_ep_info *sch_ep)
{
+ struct mu3h_sch_bw_info *sch_bw = sch_ep->bw_info;
const u32 esit_boundary = get_esit_boundary(sch_ep);
const u32 bw_boundary = get_bw_boundary(sch_ep->speed);
u32 offset;
@@ -624,23 +636,26 @@ static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
return load_ep_bw(sch_bw, sch_ep, true);
}

-static void destroy_sch_ep(struct usb_device *udev,
- struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
+static void destroy_sch_ep(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
+ struct mu3h_sch_ep_info *sch_ep)
{
/* only release ep bw check passed by check_sch_bw() */
if (sch_ep->allocated)
- load_ep_bw(sch_bw, sch_ep, false);
+ load_ep_bw(sch_ep->bw_info, sch_ep, false);

if (sch_ep->sch_tt)
drop_tt(udev);

list_del(&sch_ep->endpoint);
+ hlist_del(&sch_ep->hentry);
kfree(sch_ep);
}

-static bool need_bw_sch(struct usb_host_endpoint *ep,
- enum usb_device_speed speed, int has_tt)
+static bool need_bw_sch(struct usb_device *udev,
+ struct usb_host_endpoint *ep)
{
+ bool has_tt = udev->tt && udev->tt->hub->parent;
+
/* only for periodic endpoints */
if (usb_endpoint_xfer_control(&ep->desc)
|| usb_endpoint_xfer_bulk(&ep->desc))
@@ -651,7 +666,7 @@ static bool need_bw_sch(struct usb_host_endpoint *ep,
* a TT are also ignored, root-hub will schedule them directly,
* but need set @bpkts field of endpoint context to 1.
*/
- if (is_fs_or_ls(speed) && !has_tt)
+ if (is_fs_or_ls(udev->speed) && !has_tt)
return false;

/* skip endpoint with zero maxpkt */
@@ -666,7 +681,6 @@ int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
struct mu3h_sch_bw_info *sch_array;
int num_usb_bus;
- int i;

/* ss IN and OUT are separated */
num_usb_bus = xhci->usb3_rhub.num_ports * 2 + xhci->usb2_rhub.num_ports;
@@ -675,12 +689,10 @@ int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
if (sch_array == NULL)
return -ENOMEM;

- for (i = 0; i < num_usb_bus; i++)
- INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
-
mtk->sch_array = sch_array;

INIT_LIST_HEAD(&mtk->bw_ep_chk_list);
+ hash_init(mtk->sch_ep_hash);

return 0;
}
@@ -704,9 +716,7 @@ static int add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
ep_index = xhci_get_endpoint_index(&ep->desc);
ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);

- xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
-
- if (!need_bw_sch(ep, udev->speed, !!virt_dev->tt_info)) {
+ if (!need_bw_sch(udev, ep)) {
/*
* set @bpkts to 1 if it is LS or FS periodic endpoint, and its
* device does not connected through an external HS hub
@@ -718,13 +728,16 @@ static int add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
return 0;
}

- sch_ep = create_sch_ep(udev, ep, ep_ctx);
+ xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
+
+ sch_ep = create_sch_ep(mtk, udev, ep, ep_ctx);
if (IS_ERR_OR_NULL(sch_ep))
return -ENOMEM;

setup_sch_info(ep_ctx, sch_ep);

list_add_tail(&sch_ep->endpoint, &mtk->bw_ep_chk_list);
+ hash_add(mtk->sch_ep_hash, &sch_ep->hentry, (unsigned long)ep);

return 0;
}
@@ -734,22 +747,18 @@ static void drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
{
struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
- struct xhci_virt_device *virt_dev;
- struct mu3h_sch_bw_info *sch_bw;
- struct mu3h_sch_ep_info *sch_ep, *tmp;
-
- virt_dev = xhci->devs[udev->slot_id];
-
- xhci_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));
+ struct mu3h_sch_ep_info *sch_ep;
+ struct hlist_node *hn;

- if (!need_bw_sch(ep, udev->speed, !!virt_dev->tt_info))
+ if (!need_bw_sch(udev, ep))
return;

- sch_bw = get_bw_info(mtk, udev, ep);
+ xhci_err(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));

- list_for_each_entry_safe(sch_ep, tmp, &sch_bw->bw_ep_list, endpoint) {
+ hash_for_each_possible_safe(mtk->sch_ep_hash, sch_ep,
+ hn, hentry, (unsigned long)ep) {
if (sch_ep->ep == ep) {
- destroy_sch_ep(udev, sch_bw, sch_ep);
+ destroy_sch_ep(mtk, udev, sch_ep);
break;
}
}
@@ -760,30 +769,22 @@ int xhci_mtk_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
struct xhci_virt_device *virt_dev = xhci->devs[udev->slot_id];
- struct mu3h_sch_bw_info *sch_bw;
- struct mu3h_sch_ep_info *sch_ep, *tmp;
+ struct mu3h_sch_ep_info *sch_ep;
int ret;

xhci_dbg(xhci, "%s() udev %s\n", __func__, dev_name(&udev->dev));

list_for_each_entry(sch_ep, &mtk->bw_ep_chk_list, endpoint) {
- sch_bw = get_bw_info(mtk, udev, sch_ep->ep);
+ struct xhci_ep_ctx *ep_ctx;
+ struct usb_host_endpoint *ep = sch_ep->ep;
+ unsigned int ep_index = xhci_get_endpoint_index(&ep->desc);

- ret = check_sch_bw(sch_bw, sch_ep);
+ ret = check_sch_bw(sch_ep);
if (ret) {
xhci_err(xhci, "Not enough bandwidth! (%s)\n",
sch_error_string(-ret));
return -ENOSPC;
}
- }
-
- list_for_each_entry_safe(sch_ep, tmp, &mtk->bw_ep_chk_list, endpoint) {
- struct xhci_ep_ctx *ep_ctx;
- struct usb_host_endpoint *ep = sch_ep->ep;
- unsigned int ep_index = xhci_get_endpoint_index(&ep->desc);
-
- sch_bw = get_bw_info(mtk, udev, ep);
- list_move_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);

ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
ep_ctx->reserved[0] = cpu_to_le32(EP_BPKTS(sch_ep->pkts)
@@ -797,22 +798,23 @@ int xhci_mtk_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
sch_ep->offset, sch_ep->repeat);
}

- return xhci_check_bandwidth(hcd, udev);
+ ret = xhci_check_bandwidth(hcd, udev);
+ if (!ret)
+ INIT_LIST_HEAD(&mtk->bw_ep_chk_list);
+
+ return ret;
}

void xhci_mtk_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
{
struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
- struct mu3h_sch_bw_info *sch_bw;
struct mu3h_sch_ep_info *sch_ep, *tmp;

xhci_dbg(xhci, "%s() udev %s\n", __func__, dev_name(&udev->dev));

- list_for_each_entry_safe(sch_ep, tmp, &mtk->bw_ep_chk_list, endpoint) {
- sch_bw = get_bw_info(mtk, udev, sch_ep->ep);
- destroy_sch_ep(udev, sch_bw, sch_ep);
- }
+ list_for_each_entry_safe(sch_ep, tmp, &mtk->bw_ep_chk_list, endpoint)
+ destroy_sch_ep(mtk, udev, sch_ep);

xhci_reset_bandwidth(hcd, udev);
}
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index eb05aaf6edbe..dc5e83f5c5cc 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -10,11 +10,15 @@
#define _XHCI_MTK_H_

#include <linux/clk.h>
+#include <linux/hashtable.h>

#include "xhci.h"

#define BULK_CLKS_NUM 5

+/* support at most 64 ep, use 32 size hash table */
+#define SCH_EP_HASH_BITS 5
+
/**
* To simplify scheduler algorithm, set a upper limit for ESIT,
* if a synchromous ep's ESIT is larger than @XHCI_MTK_MAX_ESIT,
@@ -36,14 +40,12 @@ struct mu3h_sch_tt {
* struct mu3h_sch_bw_info: schedule information for bandwidth domain
*
* @bus_bw: array to keep track of bandwidth already used at each uframes
- * @bw_ep_list: eps in the bandwidth domain
*
* treat a HS root port as a bandwidth domain, but treat a SS root port as
* two bandwidth domains, one for IN eps and another for OUT eps.
*/
struct mu3h_sch_bw_info {
u32 bus_bw[XHCI_MTK_MAX_ESIT];
- struct list_head bw_ep_list;
};

/**
@@ -54,8 +56,10 @@ struct mu3h_sch_bw_info {
* @num_budget_microframes: number of continuous uframes
* (@repeat==1) scheduled within the interval
* @bw_cost_per_microframe: bandwidth cost per microframe
+ * @hentry: hash table entry
* @endpoint: linked into bandwidth domain which it belongs to
* @tt_endpoint: linked into mu3h_sch_tt's list which it belongs to
+ * @bw_info: bandwidth domain which this endpoint belongs
* @sch_tt: mu3h_sch_tt linked into
* @ep_type: endpoint type
* @maxpkt: max packet size of endpoint
@@ -84,7 +88,9 @@ struct mu3h_sch_ep_info {
u32 num_budget_microframes;
u32 bw_cost_per_microframe;
struct list_head endpoint;
+ struct hlist_node hentry;
struct list_head tt_endpoint;
+ struct mu3h_sch_bw_info *bw_info;
struct mu3h_sch_tt *sch_tt;
u32 ep_type;
u32 maxpkt;
@@ -137,6 +143,7 @@ struct xhci_hcd_mtk {
struct usb_hcd *hcd;
struct mu3h_sch_bw_info *sch_array;
struct list_head bw_ep_chk_list;
+ DECLARE_HASHTABLE(sch_ep_hash, SCH_EP_HASH_BITS);
struct mu3c_ippc_regs __iomem *ippc_regs;
int num_u2_ports;
int num_u3_ports;
--
2.18.0