[PATCH 6.8 033/143] wifi: mt76: mt7915: add locking for accessing mapped registers

Greg Kroah-Hartman
2024-04-11T10:08:16Z

From: Shayne Chen <shayne.chen@mediatek.com>

[ Upstream commit 0937f95ab07af6e663ae932d592f630d9eb591da ]

Sicne the mapping is global, mapped register access needs to be protected
against concurrent access, otherwise a race condition might cause the reads
or writes to go towards the wrong register

Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/wireless/mediatek/mt76/mt7915/mmio.c | 45 ++++++++++++++++---
.../wireless/mediatek/mt76/mt7915/mt7915.h | 1 +
2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mmio.c b/drivers/net/wireless/mediatek/mt76/mt7915/mmio.c
index 3039f53e22454..dceb505987b19 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mmio.c
@@ -490,6 +490,11 @@ static u32 __mt7915_reg_addr(struct mt7915_dev *dev, u32 addr)
return dev->reg.map[i].maps + ofs;
}

+ return 0;
+}
+
+static u32 __mt7915_reg_remap_addr(struct mt7915_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))
@@ -514,15 +519,30 @@ void mt7915_memcpy_fromio(struct mt7915_dev *dev, void *buf, u32 offset,
{
u32 addr = __mt7915_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 +
+ __mt7915_reg_remap_addr(dev, offset), len);
+ spin_unlock_bh(&dev->reg_lock);
}

static u32 mt7915_rr(struct mt76_dev *mdev, u32 offset)
{
struct mt7915_dev *dev = container_of(mdev, struct mt7915_dev, mt76);
- u32 addr = __mt7915_reg_addr(dev, offset);
+ u32 addr = __mt7915_reg_addr(dev, offset), val;

- return dev->bus_ops->rr(mdev, addr);
+ if (addr)
+ return dev->bus_ops->rr(mdev, addr);
+
+ spin_lock_bh(&dev->reg_lock);
+ val = dev->bus_ops->rr(mdev, __mt7915_reg_remap_addr(dev, offset));
+ spin_unlock_bh(&dev->reg_lock);
+
+ return val;
}

static void mt7915_wr(struct mt76_dev *mdev, u32 offset, u32 val)
@@ -530,7 +550,14 @@ static void mt7915_wr(struct mt76_dev *mdev, u32 offset, u32 val)
struct mt7915_dev *dev = container_of(mdev, struct mt7915_dev, mt76);
u32 addr = __mt7915_reg_addr(dev, offset);

- dev->bus_ops->wr(mdev, addr, val);
+ if (addr) {
+ dev->bus_ops->wr(mdev, addr, val);
+ return;
+ }
+
+ spin_lock_bh(&dev->reg_lock);
+ dev->bus_ops->wr(mdev, __mt7915_reg_remap_addr(dev, offset), val);
+ spin_unlock_bh(&dev->reg_lock);
}

static u32 mt7915_rmw(struct mt76_dev *mdev, u32 offset, u32 mask, u32 val)
@@ -538,7 +565,14 @@ static u32 mt7915_rmw(struct mt76_dev *mdev, u32 offset, u32 mask, u32 val)
struct mt7915_dev *dev = container_of(mdev, struct mt7915_dev, mt76);
u32 addr = __mt7915_reg_addr(dev, offset);

- return dev->bus_ops->rmw(mdev, addr, mask, val);
+ if (addr)
+ return dev->bus_ops->rmw(mdev, addr, mask, val);
+
+ spin_lock_bh(&dev->reg_lock);
+ val = dev->bus_ops->rmw(mdev, __mt7915_reg_remap_addr(dev, offset), mask, val);
+ spin_unlock_bh(&dev->reg_lock);
+
+ return val;
}

#ifdef CONFIG_NET_MEDIATEK_SOC_WED
@@ -707,6 +741,7 @@ static int mt7915_mmio_init(struct mt76_dev *mdev,

dev = container_of(mdev, struct mt7915_dev, mt76);
mt76_mmio_init(&dev->mt76, mem_base);
+ spin_lock_init(&dev->reg_lock);

switch (device_id) {
case 0x7915:
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h b/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h
index 4727d9c7b11de..6e79bc65f5a51 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h
@@ -287,6 +287,7 @@ struct mt7915_dev {

struct list_head sta_rc_list;
struct list_head twt_list;
+ spinlock_t reg_lock;

u32 hw_pattern;

--
2.43.0