This is a note to let you know that I've just added the patch titled
wifi: mt76: mt7996: add locking for accessing mapped registers
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
wifi-mt76-mt7996-add-locking-for-accessing-mapped-re.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dfc0f43c69ba4ecc8c37179309bdb3f0c1ae41e8
Author: Shayne Chen <shayne.chen@xxxxxxxxxxxx>
Date: Fri Jan 26 17:09:21 2024 +0800
wifi: mt76: mt7996: add locking for accessing mapped registers
[ Upstream commit 3687854d3e7e7fd760d939dd9e5a3520d5ab60fe ]
A race condition was observed when accessing mapped registers, so add
locking to protect against concurrent access.
Signed-off-by: Shayne Chen <shayne.chen@xxxxxxxxxxxx>
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
index 9f2abfa273c9b..efd4a767eb37d 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
@@ -140,7 +140,6 @@ static u32 mt7996_reg_map_l1(struct mt7996_dev *dev, u32 addr)
u32 offset = FIELD_GET(MT_HIF_REMAP_L1_OFFSET, addr);
u32 base = FIELD_GET(MT_HIF_REMAP_L1_BASE, addr);
- dev->reg_l1_backup = dev->bus_ops->rr(&dev->mt76, MT_HIF_REMAP_L1);
dev->bus_ops->rmw(&dev->mt76, MT_HIF_REMAP_L1,
MT_HIF_REMAP_L1_MASK,
FIELD_PREP(MT_HIF_REMAP_L1_MASK, base));
@@ -155,7 +154,6 @@ static u32 mt7996_reg_map_l2(struct mt7996_dev *dev, u32 addr)
u32 offset = FIELD_GET(MT_HIF_REMAP_L2_OFFSET, addr);
u32 base = FIELD_GET(MT_HIF_REMAP_L2_BASE, addr);
- dev->reg_l2_backup = dev->bus_ops->rr(&dev->mt76, MT_HIF_REMAP_L2);
dev->bus_ops->rmw(&dev->mt76, MT_HIF_REMAP_L2,
MT_HIF_REMAP_L2_MASK,
FIELD_PREP(MT_HIF_REMAP_L2_MASK, base));
@@ -165,26 +163,10 @@ static u32 mt7996_reg_map_l2(struct mt7996_dev *dev, u32 addr)
return MT_HIF_REMAP_BASE_L2 + offset;
}
-static void mt7996_reg_remap_restore(struct mt7996_dev *dev)
-{
- /* remap to ori status */
- if (unlikely(dev->reg_l1_backup)) {
- dev->bus_ops->wr(&dev->mt76, MT_HIF_REMAP_L1, dev->reg_l1_backup);
- dev->reg_l1_backup = 0;
- }
-
- if (dev->reg_l2_backup) {
- dev->bus_ops->wr(&dev->mt76, MT_HIF_REMAP_L2, dev->reg_l2_backup);
- dev->reg_l2_backup = 0;
- }
-}
-
static u32 __mt7996_reg_addr(struct mt7996_dev *dev, u32 addr)
{
int i;
- mt7996_reg_remap_restore(dev);
-
if (addr < 0x100000)
return addr;
@@ -201,6 +183,11 @@ static u32 __mt7996_reg_addr(struct mt7996_dev *dev, u32 addr)
return dev->reg.map[i].mapped + ofs;
}
+ return 0;
+}
+
+static u32 __mt7996_reg_remap_addr(struct mt7996_dev *dev, u32 addr)
+{
if ((addr >= MT_INFRA_BASE && addr < MT_WFSYS0_PHY_START) ||
(addr >= MT_WFSYS0_PHY_START && addr < MT_WFSYS1_PHY_START) ||
(addr >= MT_WFSYS1_PHY_START && addr <= MT_WFSYS1_PHY_END))
@@ -225,28 +212,60 @@ void mt7996_memcpy_fromio(struct mt7996_dev *dev, void *buf, u32 offset,
{
u32 addr = __mt7996_reg_addr(dev, offset);
- memcpy_fromio(buf, dev->mt76.mmio.regs + addr, len);
+ if (addr) {
+ memcpy_fromio(buf, dev->mt76.mmio.regs + addr, len);
+ return;
+ }
+
+ spin_lock_bh(&dev->reg_lock);
+ memcpy_fromio(buf, dev->mt76.mmio.regs +
+ __mt7996_reg_remap_addr(dev, offset), len);
+ spin_unlock_bh(&dev->reg_lock);
}
static u32 mt7996_rr(struct mt76_dev *mdev, u32 offset)
{
struct mt7996_dev *dev = container_of(mdev, struct mt7996_dev, mt76);
+ u32 addr = __mt7996_reg_addr(dev, offset), val;
+
+ if (addr)
+ return dev->bus_ops->rr(mdev, addr);
- return dev->bus_ops->rr(mdev, __mt7996_reg_addr(dev, offset));
+ spin_lock_bh(&dev->reg_lock);
+ val = dev->bus_ops->rr(mdev, __mt7996_reg_remap_addr(dev, offset));
+ spin_unlock_bh(&dev->reg_lock);
+
+ return val;
}
static void mt7996_wr(struct mt76_dev *mdev, u32 offset, u32 val)
{
struct mt7996_dev *dev = container_of(mdev, struct mt7996_dev, mt76);
+ u32 addr = __mt7996_reg_addr(dev, offset);
- dev->bus_ops->wr(mdev, __mt7996_reg_addr(dev, offset), val);
+ if (addr) {
+ dev->bus_ops->wr(mdev, addr, val);
+ return;
+ }
+
+ spin_lock_bh(&dev->reg_lock);
+ dev->bus_ops->wr(mdev, __mt7996_reg_remap_addr(dev, offset), val);
+ spin_unlock_bh(&dev->reg_lock);
}
static u32 mt7996_rmw(struct mt76_dev *mdev, u32 offset, u32 mask, u32 val)
{
struct mt7996_dev *dev = container_of(mdev, struct mt7996_dev, mt76);
+ u32 addr = __mt7996_reg_addr(dev, offset);
+
+ if (addr)
+ return dev->bus_ops->rmw(mdev, addr, mask, val);
+
+ spin_lock_bh(&dev->reg_lock);
+ val = dev->bus_ops->rmw(mdev, __mt7996_reg_remap_addr(dev, offset), mask, val);
+ spin_unlock_bh(&dev->reg_lock);
- return dev->bus_ops->rmw(mdev, __mt7996_reg_addr(dev, offset), mask, val);
+ return val;
}
#ifdef CONFIG_NET_MEDIATEK_SOC_WED
@@ -421,6 +440,7 @@ static int mt7996_mmio_init(struct mt76_dev *mdev,
dev = container_of(mdev, struct mt7996_dev, mt76);
mt76_mmio_init(&dev->mt76, mem_base);
+ spin_lock_init(&dev->reg_lock);
switch (device_id) {
case 0x7990:
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
index 8154ad37827f0..36d1f247d55aa 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
@@ -325,8 +325,7 @@ struct mt7996_dev {
u8 n_agrt;
} twt;
- u32 reg_l1_backup;
- u32 reg_l2_backup;
+ spinlock_t reg_lock;
u8 wtbl_size_group;
};
