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usb: xhci-mtk: Do not use xhci's virt_dev in drop_endpoint
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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 rhashtable 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] https://lore.kernel.org/r/1617179142-2681-2-git-send-email-chunfeng.yun@mediatek.com

Signed-off-by: Ikjoon Jang <ikjn@chromium.org>
Link: https://lore.kernel.org/r/20210805133731.1.Icc0f080e75b1312692d4c7c7d25e7df9fe1a05c2@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@ikjn-cros @gregkh
ikjn-cros authored and gregkh committed Aug 5, 2021
1 parent 177cd47 commit b873120
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Showing 2 changed files with 86 additions and 69 deletions.
140 changes: 78 additions & 62 deletions drivers/usb/host/xhci-mtk-sch.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)),
Expand Down Expand Up @@ -129,6 +129,12 @@ get_bw_info(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
int bw_index;

virt_dev = xhci->devs[udev->slot_id];
if (WARN_ONCE(!virt_dev, "xhci-mtk: usb %s has no virt_dev\n",
dev_name(&udev->dev)))
return NULL;
if (WARN_ONCE(!virt_dev->real_port, "xhci-mtk: usb %s has invalid port number\n",
dev_name(&udev->dev)))
return NULL;

if (udev->speed >= USB_SPEED_SUPER) {
if (usb_endpoint_dir_out(&ep->desc))
Expand Down Expand Up @@ -194,7 +200,6 @@ static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
}
return ERR_PTR(-ENOMEM);
}
INIT_LIST_HEAD(&tt->ep_list);
*ptt = tt;
}

Expand Down Expand Up @@ -224,7 +229,7 @@ static void drop_tt(struct usb_device *udev)
}

tt = *ptt;
if (!tt || !list_empty(&tt->ep_list))
if (!tt || tt->nr_eps > 0)
return; /* never allocated , or still in use*/

*ptt = NULL;
Expand All @@ -236,13 +241,19 @@ 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_tt *tt = NULL;
u32 len_bw_budget_table;
size_t mem_size;
struct mu3h_sch_bw_info *bw_info;

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;
Expand All @@ -266,11 +277,10 @@ 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);

return sch_ep;
}
Expand Down Expand Up @@ -552,9 +562,9 @@ static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
}

if (used)
list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
else
list_del(&sch_ep->tt_endpoint);
tt->nr_eps++;
else if (!WARN_ONCE(tt->nr_eps < 1, "unbalanced sch_tt's ep count"))
tt->nr_eps--;
}

static int load_ep_bw(struct mu3h_sch_bw_info *sch_bw,
Expand Down Expand Up @@ -585,9 +595,9 @@ 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;
Expand Down Expand Up @@ -633,23 +643,33 @@ 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 const struct rhashtable_params sch_ep_table_param = {
.key_len = sizeof(struct usb_host_endpoint *),
.key_offset = offsetof(struct mu3h_sch_ep_info, ep),
.head_offset = offsetof(struct mu3h_sch_ep_info, ep_link),
};

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);
rhashtable_remove_fast(&mtk->sch_ep_table, &sch_ep->ep_link,
sch_ep_table_param);
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))
Expand All @@ -660,7 +680,7 @@ 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 */
Expand All @@ -675,7 +695,12 @@ 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;
int ret;

/* mu3h_sch_ep_info table, 'usb_host_endpoint*' as a key */
ret = rhashtable_init(&mtk->sch_ep_table, &sch_ep_table_param);
if (ret)
return ret;

/* ss IN and OUT are separated */
num_usb_bus = xhci->usb3_rhub.num_ports * 2 + xhci->usb2_rhub.num_ports;
Expand All @@ -684,9 +709,6 @@ 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);
Expand All @@ -696,6 +718,7 @@ int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)

void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
{
rhashtable_destroy(&mtk->sch_ep_table);
kfree(mtk->sch_array);
}

Expand All @@ -713,9 +736,7 @@ 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
Expand All @@ -727,14 +748,22 @@ 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;

if (rhashtable_insert_fast(&mtk->sch_ep_table, &sch_ep->ep_link,
sch_ep_table_param))
return -EEXIST;

setup_sch_info(ep_ctx, sch_ep);

list_add_tail(&sch_ep->endpoint, &mtk->bw_ep_chk_list);

xhci_dbg(xhci, "added sch_ep %p : %p\n", sch_ep, ep);

return 0;
}

Expand All @@ -743,56 +772,43 @@ 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;
void *key = ep;

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_dbg(xhci, "%s %s\n", __func__, decode_ep(ep, udev->speed));

list_for_each_entry_safe(sch_ep, tmp, &sch_bw->bw_ep_list, endpoint) {
if (sch_ep->ep == ep) {
destroy_sch_ep(udev, sch_bw, sch_ep);
break;
}
}
sch_ep = rhashtable_lookup_fast(&mtk->sch_ep_table, &key,
sch_ep_table_param);
if (sch_ep)
destroy_sch_ep(mtk, udev, sch_ep);
else
xhci_dbg(xhci, "ep %p is not on the bw table\n", ep);
}

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)
Expand All @@ -806,22 +822,23 @@ 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);
}
Expand Down Expand Up @@ -850,8 +867,7 @@ int xhci_mtk_drop_ep(struct usb_hcd *hcd, struct usb_device *udev,
if (ret)
return ret;

if (ep->hcpriv)
drop_ep_quirk(hcd, udev, ep);
drop_ep_quirk(hcd, udev, ep);

return 0;
}
15 changes: 8 additions & 7 deletions drivers/usb/host/xhci-mtk.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@
#define _XHCI_MTK_H_

#include <linux/clk.h>
#include <linux/rhashtable.h>

#include "xhci.h"

Expand All @@ -25,36 +26,34 @@

/**
* @fs_bus_bw: array to keep track of bandwidth already used for FS
* @ep_list: Endpoints using this TT
* @nr_eps: number of endpoints using this TT
*/
struct mu3h_sch_tt {
u32 fs_bus_bw[XHCI_MTK_MAX_ESIT];
struct list_head ep_list;
int nr_eps;
};

/**
* 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;
};

/**
* struct mu3h_sch_ep_info: schedule information for endpoint
*
* @bw_info: bandwidth domain which this endpoint belongs
* @esit: unit is 125us, equal to 2 << Interval field in ep-context
* @num_budget_microframes: number of continuous uframes
* (@repeat==1) scheduled within the interval
* @bw_cost_per_microframe: bandwidth cost per microframe
* @endpoint: linked into bandwidth domain which it belongs to
* @tt_endpoint: linked into mu3h_sch_tt's list which it belongs to
* @endpoint: linked into bw_ep_chk_list, used by check_bandwidth hook
* @sch_tt: mu3h_sch_tt linked into
* @ep_type: endpoint type
* @maxpkt: max packet size of endpoint
Expand Down Expand Up @@ -82,11 +81,12 @@ struct mu3h_sch_ep_info {
u32 num_budget_microframes;
u32 bw_cost_per_microframe;
struct list_head endpoint;
struct list_head tt_endpoint;
struct mu3h_sch_bw_info *bw_info;
struct mu3h_sch_tt *sch_tt;
u32 ep_type;
u32 maxpkt;
struct usb_host_endpoint *ep;
struct rhash_head ep_link;
enum usb_device_speed speed;
bool allocated;
/*
Expand Down Expand Up @@ -134,6 +134,7 @@ struct xhci_hcd_mtk {
struct device *dev;
struct usb_hcd *hcd;
struct mu3h_sch_bw_info *sch_array;
struct rhashtable sch_ep_table;
struct list_head bw_ep_chk_list;
struct mu3c_ippc_regs __iomem *ippc_regs;
int num_u2_ports;
Expand Down

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