[tip: irq/core] net/mlx4: Replace irq_to_desc() abuse

From: tip-bot2 for Thomas Gleixner
Date: Sat Dec 12 2020 - 08:07:49 EST


The following commit has been merged into the irq/core branch of tip:

Commit-ID: 5ea444c8f27b50f14ccfece192a6199d3ada9253
Gitweb: https://git.kernel.org/tip/5ea444c8f27b50f14ccfece192a6199d3ada9253
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 10 Dec 2020 20:25:56 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Sat, 12 Dec 2020 12:59:05 +01:00

net/mlx4: Replace irq_to_desc() abuse

No driver has any business with the internals of an interrupt
descriptor. Storing a pointer to it just to use yet another helper at the
actual usage site to retrieve the affinity mask is creative at best. Just
because C does not allow encapsulation does not mean that the kernel has no
limits.

Retrieve a pointer to the affinity mask itself and use that. It's still
using an interface which is usually not for random drivers, but definitely
less hideous than the previous hack.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tariq Toukan <tariqt@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20201210194044.580936243@xxxxxxxxxxxxx

---
drivers/net/ethernet/mellanox/mlx4/en_cq.c | 8 +++-----
drivers/net/ethernet/mellanox/mlx4/en_rx.c | 6 +-----
drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 3 ++-
3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index 74d4667..2a250f3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -90,7 +90,7 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,
int cq_idx)
{
struct mlx4_en_dev *mdev = priv->mdev;
- int err = 0;
+ int irq, err = 0;
int timestamp_en = 0;
bool assigned_eq = false;

@@ -116,10 +116,8 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,

assigned_eq = true;
}
-
- cq->irq_desc =
- irq_to_desc(mlx4_eq_get_irq(mdev->dev,
- cq->vector));
+ irq = mlx4_eq_get_irq(mdev->dev, cq->vector);
+ cq->aff_mask = irq_get_affinity_mask(irq);
} else {
/* For TX we use the same irq per
ring we assigned for the RX */
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 502d1b9..399459a 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -959,8 +959,6 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)

/* If we used up all the quota - we're probably not done yet... */
if (done == budget || !clean_complete) {
- const struct cpumask *aff;
- struct irq_data *idata;
int cpu_curr;

/* in case we got here because of !clean_complete */
@@ -969,10 +967,8 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
INC_PERF_COUNTER(priv->pstats.napi_quota);

cpu_curr = smp_processor_id();
- idata = irq_desc_get_irq_data(cq->irq_desc);
- aff = irq_data_get_affinity_mask(idata);

- if (likely(cpumask_test_cpu(cpu_curr, aff)))
+ if (likely(cpumask_test_cpu(cpu_curr, cq->aff_mask)))
return budget;

/* Current cpu is not according to smp_irq_affinity -
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index a46efe3..48d71e0 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -46,6 +46,7 @@
#endif
#include <linux/cpu_rmap.h>
#include <linux/ptp_clock_kernel.h>
+#include <linux/irq.h>
#include <net/xdp.h>

#include <linux/mlx4/device.h>
@@ -380,7 +381,7 @@ struct mlx4_en_cq {
struct mlx4_cqe *buf;
#define MLX4_EN_OPCODE_ERROR 0x1e

- struct irq_desc *irq_desc;
+ const struct cpumask *aff_mask;
};

struct mlx4_en_port_profile {