From: Kanchana Velusamy <kanchanax.velusamy@xxxxxxxxx>
In the PF interrupt handler, the interrupt is disabled for a set of VFs
by writing to the interrupt source mask register, ERRMSK.
The interrupt is re-enabled in the bottom half handler by writing to the
same CSR. This is done through the functions enable_vf2pf_interrupts()
and disable_vf2pf_interrupts() which perform a read-modify-write
operation on the ERRMSK registers to mask and unmask the source of
interrupt.
There can be a race condition where the top half handler for one VF
interrupt runs just as the bottom half for another VF is about to
re-enable the interrupt. Depending on whether the top or bottom half
updates the CSR first, this would result either in a spurious interrupt
or in the interrupt not being re-enabled.
This patch protects the access of ERRMSK with a spinlock.
The functions adf_enable_vf2pf_interrupts() and
adf_disable_vf2pf_interrupts() have been changed to acquire a spin lock
before accessing and modifying the ERRMSK registers. These functions use
spin_lock_irqsave() to disable IRQs and avoid potential deadlocks.
In addition, the function adf_disable_vf2pf_interrupts_irq() has been
added. This uses spin_lock() and it is meant to be used in the top half
only.
Signed-off-by: Kanchana Velusamy <kanchanax.velusamy@xxxxxxxxx>
Co-developed-by: Marco Chiappero <marco.chiappero@xxxxxxxxx>
Signed-off-by: Marco Chiappero <marco.chiappero@xxxxxxxxx>
Co-developed-by: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx>
Reviewed-by: Fiona Trahe <fiona.trahe@xxxxxxxxx>
---
.../crypto/qat/qat_c3xxx/adf_c3xxx_hw_data.c | 2 ++
.../crypto/qat/qat_c62x/adf_c62x_hw_data.c | 2 ++
.../crypto/qat/qat_common/adf_accel_devices.h | 2 ++
.../crypto/qat/qat_common/adf_common_drv.h | 2 ++
drivers/crypto/qat/qat_common/adf_isr.c | 2 +-
drivers/crypto/qat/qat_common/adf_pf2vf_msg.c | 33 +++++++++++++++++--
.../qat/qat_dh895xcc/adf_dh895xcc_hw_data.c | 2 ++
7 files changed, 41 insertions(+), 4 deletions(-)
diff --git a/drivers/crypto/qat/qat_c3xxx/adf_c3xxx_hw_data.c b/drivers/crypto/qat/qat_c3xxx/adf_c3xxx_hw_data.c
index 1c7f6a6f6f2d..912e84ecb9a3 100644
--- a/drivers/crypto/qat/qat_c3xxx/adf_c3xxx_hw_data.c
+++ b/drivers/crypto/qat/qat_c3xxx/adf_c3xxx_hw_data.c
@@ -161,6 +161,8 @@ static void adf_enable_ints(struct adf_accel_dev *accel_dev)
static int adf_pf_enable_vf2pf_comms(struct adf_accel_dev *accel_dev)
{
+ spin_lock_init(&accel_dev->pf.vf2pf_ints_lock);
+
return 0;
}
diff --git a/drivers/crypto/qat/qat_c62x/adf_c62x_hw_data.c b/drivers/crypto/qat/qat_c62x/adf_c62x_hw_data.c
index a202f912820c..069b5d6857e8 100644
--- a/drivers/crypto/qat/qat_c62x/adf_c62x_hw_data.c
+++ b/drivers/crypto/qat/qat_c62x/adf_c62x_hw_data.c
@@ -163,6 +163,8 @@ static void adf_enable_ints(struct adf_accel_dev *accel_dev)
static int adf_pf_enable_vf2pf_comms(struct adf_accel_dev *accel_dev)
{
+ spin_lock_init(&accel_dev->pf.vf2pf_ints_lock);
+
return 0;
}
diff --git a/drivers/crypto/qat/qat_common/adf_accel_devices.h b/drivers/crypto/qat/qat_common/adf_accel_devices.h
index 180c7dba3ff2..8250cf856e07 100644
--- a/drivers/crypto/qat/qat_common/adf_accel_devices.h
+++ b/drivers/crypto/qat/qat_common/adf_accel_devices.h
@@ -246,6 +246,8 @@ struct adf_accel_dev {
struct adf_accel_pci accel_pci_dev;
union {
struct {
+ /* protects VF2PF interrupts access */
+ spinlock_t vf2pf_ints_lock;
/* vf_info is non-zero when SR-IOV is init'ed */
struct adf_accel_vf_info *vf_info;
} pf;
diff --git a/drivers/crypto/qat/qat_common/adf_common_drv.h b/drivers/crypto/qat/qat_common/adf_common_drv.h
index bd76b8a86b86..3f6277347278 100644
--- a/drivers/crypto/qat/qat_common/adf_common_drv.h
+++ b/drivers/crypto/qat/qat_common/adf_common_drv.h
@@ -193,6 +193,8 @@ int adf_sriov_configure(struct pci_dev *pdev, int numvfs);
void adf_disable_sriov(struct adf_accel_dev *accel_dev);
void adf_disable_vf2pf_interrupts(struct adf_accel_dev *accel_dev,
u32 vf_mask);
+void adf_disable_vf2pf_interrupts_irq(struct adf_accel_dev *accel_dev,
+ u32 vf_mask);
void adf_enable_vf2pf_interrupts(struct adf_accel_dev *accel_dev,
u32 vf_mask);
void adf_enable_pf2vf_interrupts(struct adf_accel_dev *accel_dev);
diff --git a/drivers/crypto/qat/qat_common/adf_isr.c b/drivers/crypto/qat/qat_common/adf_isr.c
index 2302e43dfaf4..c678d5c531aa 100644
--- a/drivers/crypto/qat/qat_common/adf_isr.c
+++ b/drivers/crypto/qat/qat_common/adf_isr.c
@@ -103,7 +103,7 @@ static irqreturn_t adf_msix_isr_ae(int irq, void *dev_ptr)
int i;
/* Disable VF2PF interrupts for VFs with pending ints */
- adf_disable_vf2pf_interrupts(accel_dev, vf_mask);
+ adf_disable_vf2pf_interrupts_irq(accel_dev, vf_mask);
/*
* Handle VF2PF interrupt unless the VF is malicious and
diff --git a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
index 0a927ed91b19..1b0df4a5b8b7 100644
--- a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
+++ b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
@@ -11,8 +11,8 @@
#define ADF_DH895XCC_ERRMSK5 (ADF_DH895XCC_EP_OFFSET + 0xDC)
#define ADF_DH895XCC_ERRMSK5_VF2PF_U_MASK(vf_mask) (vf_mask >> 16)
-void adf_enable_vf2pf_interrupts(struct adf_accel_dev *accel_dev,
- u32 vf_mask)
+static void __adf_enable_vf2pf_interrupts(struct adf_accel_dev *accel_dev,
+ u32 vf_mask)
{
struct adf_hw_device_data *hw_data = accel_dev->hw_device;
struct adf_bar *pmisc =
@@ -35,7 +35,17 @@ void adf_enable_vf2pf_interrupts(struct adf_accel_dev *accel_dev,
}
}
-void adf_disable_vf2pf_interrupts(struct adf_accel_dev *accel_dev, u32 vf_mask)
+void adf_enable_vf2pf_interrupts(struct adf_accel_dev *accel_dev, u32 vf_mask)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&accel_dev->pf.vf2pf_ints_lock, flags);
+ __adf_enable_vf2pf_interrupts(accel_dev, vf_mask);
+ spin_unlock_irqrestore(&accel_dev->pf.vf2pf_ints_lock, flags);
+}
+
+static void __adf_disable_vf2pf_interrupts(struct adf_accel_dev *accel_dev,
+ u32 vf_mask)
{
struct adf_hw_device_data *hw_data = accel_dev->hw_device;
struct adf_bar *pmisc =
@@ -58,6 +68,22 @@ void adf_disable_vf2pf_interrupts(struct adf_accel_dev *accel_dev, u32 vf_mask)
}
}
+void adf_disable_vf2pf_interrupts(struct adf_accel_dev *accel_dev, u32 vf_mask)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&accel_dev->pf.vf2pf_ints_lock, flags);
+ __adf_disable_vf2pf_interrupts(accel_dev, vf_mask);
+ spin_unlock_irqrestore(&accel_dev->pf.vf2pf_ints_lock, flags);
+}
+
+void adf_disable_vf2pf_interrupts_irq(struct adf_accel_dev *accel_dev, u32 vf_mask)
+{
+ spin_lock(&accel_dev->pf.vf2pf_ints_lock);
+ __adf_disable_vf2pf_interrupts(accel_dev, vf_mask);
+ spin_unlock(&accel_dev->pf.vf2pf_ints_lock);
+}
+
static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
{
struct adf_accel_pci *pci_info = &accel_dev->accel_pci_dev;
@@ -264,6 +290,7 @@ void adf_vf2pf_req_hndl(struct adf_accel_vf_info *vf_info)
/* re-enable interrupt on PF from this VF */
adf_enable_vf2pf_interrupts(accel_dev, (1 << vf_nr));
+
return;
err:
dev_dbg(&GET_DEV(accel_dev), "Unknown message from VF%d (0x%x);\n",
diff --git a/drivers/crypto/qat/qat_dh895xcc/adf_dh895xcc_hw_data.c b/drivers/crypto/qat/qat_dh895xcc/adf_dh895xcc_hw_data.c
index dced2426edc1..07e7ba5c057d 100644
--- a/drivers/crypto/qat/qat_dh895xcc/adf_dh895xcc_hw_data.c
+++ b/drivers/crypto/qat/qat_dh895xcc/adf_dh895xcc_hw_data.c
@@ -182,6 +182,8 @@ static void adf_enable_ints(struct adf_accel_dev *accel_dev)
static int adf_pf_enable_vf2pf_comms(struct adf_accel_dev *accel_dev)
{
+ spin_lock_init(&accel_dev->pf.vf2pf_ints_lock);
+
return 0;
}
--
2.31.1
