net/mlx5: Free used cpus mask when an IRQ is released

Each EQ table maintains a cpumask of the already used CPUs that are mapped
to IRQs to ensure that each IRQ gets mapped to a unique CPU.

However, on IRQ release, the said cpumask is not updated by clearing the
CPU from the mask to allow future IRQ request, causing the following
error when a SF is reloaded after it has utilized all CPUs for its IRQs:

mlx5_irq_affinity_request:135:(pid 306010): Didn't find a matching IRQ.
err = -28

Thus, when releasing an IRQ, clear its mapped CPU from the used CPUs
mask, to prevent the case described above.

While at it, move the used cpumask update to the EQ layer as it is more
fitting and preserves symmetricity of the IRQ request/release API.

Fixes: a1772de78d73 ("net/mlx5: Refactor completion IRQ request/release API")
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20231114215846.5902-3-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mlx5: Handle SF IRQ request in the absence of SF IRQ pool

In case the SF IRQ pool is not available due to setup limitations,
SF currently relies on the already allocated PF IRQs to fulfill
its IRQ vector requests.

However, with the dynamic EQ allocation introduced in the next patch,
it is possible that not all IRQs of PF will be allocated after the driver
is loaded. In such case, if a SF requests a completion IRQ without having
its own independent IRQ pool, SF will lack a PF IRQ to utilize.

To address this scenario, allocate an IRQ for the SF from the PF's IRQ pool
on demand. The new IRQ will be shared between the SF and it's PF.

Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5: Refactor completion IRQ request/release API

Introduce a per-vector completion IRQ request API that requests a
single IRQ for a given vector index instead of multiple IRQs request API.
On driver load, loop over all completion vectors and request an IRQ for
each one via the newly introduced API.

Symmetrically, introduce an IRQ release API per vector. On driver
unload, loop over all vectors and release each completion IRQ via
the new per-vector API.

As IRQ vectors will be requested dynamically later in the patchset,
add a cpumask of the bounded CPUs to avoid the possible mapping of
two IRQs of the same device to the same cpu.

Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5: Use dynamic msix vectors allocation

Current implementation calculates the number and the partitioaning of
available interrupts vectors and then allocates all the interrupt
vectors.

Here, whenever dynamic msix allocation is supported, we change this to
use msix vectors dynamically so a vectors is actually allocated only
when needed. The current pool logic is kept in place to take care of
partitioning the vectors between the consumers and take care of
reference counting. However, the vectors are allocated only when needed.

Subsequent patches will make use of this to allocate vectors for VDPA.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>

net/mlx5: Use newer affinity descriptor

Use the more refined struct irq_affinity_desc to describe the required
IRQ affinity. For the async IRQs request unmanaged affinity and for
completion queues use managed affinity.

No functionality changes introduced. It will be used in a subsequent
patch when we use dynamic MSIX allocation.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>

net/mlx5: SF, Use all available cpu for setting cpu affinity

Currently all SFs are using the same CPUs. Spreading SF over CPUs, in
round-robin manner, in order to achieve better distribution of the SFs
over available CPUs.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5: Split irq_pool_affinity logic to new file

The downstream patches add more functionality to irq_pool_affinity.
Move the irq_pool_affinity logic to a new file in order to ease the
coding and maintenance of it.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>