From 07df385e645ed3b7fd3ac2d5c4c3e825b54bb7e4 Mon Sep 17 00:00:00 2001 From: Kanchana Velusamy Date: Thu, 12 Aug 2021 21:21:21 +0100 Subject: [PATCH] crypto: qat - protect interrupt mask CSRs with a spinlock 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 Co-developed-by: Marco Chiappero Signed-off-by: Marco Chiappero Co-developed-by: Giovanni Cabiddu Signed-off-by: Giovanni Cabiddu Reviewed-by: Fiona Trahe Signed-off-by: Herbert Xu --- drivers/crypto/qat/qat_c3xxx/adf_c3xxx_hw_data.c | 2 ++ drivers/crypto/qat/qat_c62x/adf_c62x_hw_data.c | 2 ++ drivers/crypto/qat/qat_common/adf_accel_devices.h | 2 ++ drivers/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 ++++++++++++++++++++-- .../crypto/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 1c7f6a6..912e84e 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 a202f91..069b5d6 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 180c7db..8250cf8 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 bd76b8a..3f62773 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 2302e43..c678d5c 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 0a927ed..1b0df4a 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 dced242..07e7ba5 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; } -- 2.7.4