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authorGiovanni Cabiddu2021-08-12 21:21:15 +0100
committerHerbert Xu2021-08-21 15:44:55 +0800
commit7eadcfd633d8ef0082b194693c5057c9652fe243 (patch)
treee9cff2fdd337d835de5a4699028c0a16638bff23
parent0a73c762e1eee33a5e5dc0e3488f1b7cd17249b3 (diff)
crypto: qat - prevent spurious MSI interrupt in VF
QAT GEN2 devices suffer from a defect where the MSI interrupt can be sent multiple times. If the second (spurious) interrupt is handled before the bottom half handler runs, then the extra interrupt is effectively ignored because the bottom half is only scheduled once. However, if the top half runs again after the bottom half runs, this will appear as a spurious PF to VF interrupt. This can be avoided by checking the interrupt mask register in addition to the interrupt source register in the interrupt handler. This patch is based on earlier work done by Conor McLoughlin. Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Co-developed-by: Marco Chiappero <marco.chiappero@intel.com> Signed-off-by: Marco Chiappero <marco.chiappero@intel.com> Reviewed-by: Fiona Trahe <fiona.trahe@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--drivers/crypto/qat/qat_common/adf_vf_isr.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/crypto/qat/qat_common/adf_vf_isr.c b/drivers/crypto/qat/qat_common/adf_vf_isr.c
index 3e4f64d248f9..4359ca633ea9 100644
--- a/drivers/crypto/qat/qat_common/adf_vf_isr.c
+++ b/drivers/crypto/qat/qat_common/adf_vf_isr.c
@@ -18,6 +18,7 @@
#include "adf_pf2vf_msg.h"
#define ADF_VINTSOU_OFFSET 0x204
+#define ADF_VINTMSK_OFFSET 0x208
#define ADF_VINTSOU_BUN BIT(0)
#define ADF_VINTSOU_PF2VF BIT(1)
@@ -161,11 +162,20 @@ static irqreturn_t adf_isr(int irq, void *privdata)
&GET_BARS(accel_dev)[hw_data->get_misc_bar_id(hw_data)];
void __iomem *pmisc_bar_addr = pmisc->virt_addr;
bool handled = false;
- u32 v_int;
+ u32 v_int, v_mask;
/* Read VF INT source CSR to determine the source of VF interrupt */
v_int = ADF_CSR_RD(pmisc_bar_addr, ADF_VINTSOU_OFFSET);
+ /* Read VF INT mask CSR to determine which sources are masked */
+ v_mask = ADF_CSR_RD(pmisc_bar_addr, ADF_VINTMSK_OFFSET);
+
+ /*
+ * Recompute v_int ignoring sources that are masked. This is to
+ * avoid rescheduling the tasklet for interrupts already handled
+ */
+ v_int &= ~v_mask;
+
/* Check for PF2VF interrupt */
if (v_int & ADF_VINTSOU_PF2VF) {
/* Disable PF to VF interrupt */