On Thu, Jun 06, 2024 at 05:33:34PM +0100, Simon Horman wrote:

On Wed, Jun 05, 2024 at 01:39:06AM -0700, Shradha Gupta wrote:

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On Tue, Jun 04, 2024 at 10:33:49AM +0100, Simon Horman wrote:

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On Fri, May 31, 2024 at 08:37:41AM -0700, Shradha Gupta wrote:

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Allow variable size indirection table allocation in MANA instead
of using a constant value MANA_INDIRECT_TABLE_SIZE.
The size is now derived from the MANA_QUERY_VPORT_CONFIG and the
indirection table is allocated dynamically.

Signed-off-by: Shradha Gupta <redacted>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>

...

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diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c

...

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@@ -2344,11 +2352,33 @@ static int mana_create_vport(struct mana_port_context *apc,
 	return mana_create_txq(apc, net);
 }
 
+static int mana_rss_table_alloc(struct mana_port_context *apc)
+{
+	if (!apc->indir_table_sz) {
+		netdev_err(apc->ndev,
+			   "Indirection table size not set for vPort %d\n",
+			   apc->port_idx);
+		return -EINVAL;
+	}
+
+	apc->indir_table = kcalloc(apc->indir_table_sz, sizeof(u32), GFP_KERNEL);
+	if (!apc->indir_table)
+		return -ENOMEM;
+
+	apc->rxobj_table = kcalloc(apc->indir_table_sz, sizeof(mana_handle_t), GFP_KERNEL);
+	if (!apc->rxobj_table) {
+		kfree(apc->indir_table);

Hi, Shradha

Perhaps I am on the wrong track here, but I have some concerns
about clean-up paths.

Firstly.  I think that apc->indir_table should be to NULL here for
consistency with other clean-up paths. Or alternatively, fields of apc
should not set to NULL elsewhere after being freed.

Hi Simon,

Thanks for the comments. This makes sense, I am planning of consistently
removing the NULLify from other places too as per Leon's comments.

Great!

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In looking into this I noticed that mana_probe() does not call
mana_remove() or return an error in the cases where mana_probe_port()
or mana_attach() fail unless add_adev also fails. If so, is that
intentional?

Right, so most calls like mana_probe_port(), mana_attach() cleanup after
themselves in the code if there is any error. So, not having to call
mana_remove() in these cases in mana_probe() is intentional. But I do
agree that an error is returned in mana_probe() only if add_adev also
fails. I'll fix that too in the next version

I'm not entirely sure, but perhaps that is a candidate for a separate patch.

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In any case, I would suggest as a follow-up, arranging things so that
when an error occurs in a function, anything that was allocated is
unwound before returning an error.

I think this would make allocation/deallocation easier to reason with.
And I suspect it would avoid both the need for fields of structures to
be zeroed after being freed, and the need to call mana_remove() from
mana_probe().

Agreed

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+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 static void mana_rss_table_init(struct mana_port_context *apc)
 {
 	int i;
 
-	for (i = 0; i < MANA_INDIRECT_TABLE_SIZE; i++)
+	for (i = 0; i < apc->indir_table_sz; i++)
 		apc->indir_table[i] =
 			ethtool_rxfh_indir_default(i, apc->num_queues);
 }

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@@ -2739,11 +2772,17 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	err = register_netdev(ndev);
 	if (err) {
 		netdev_err(ndev, "Unable to register netdev.\n");
-		goto reset_apc;
+		goto free_indir;
 	}
 
 	return 0;
 
+free_indir:
+	apc->indir_table_sz = 0;
+	kfree(apc->indir_table);
+	apc->indir_table = NULL;
+	kfree(apc->rxobj_table);
+	apc->rxobj_table = NULL;
 reset_apc:
 	kfree(apc->rxqs);
 	apc->rxqs = NULL;

nit: Not strictly related to this patch, but the reset_apc code should
     probably be a call to mana_cleanup_port_context() as it is the dual of
     mana_init_port_context() which is called earlier in mana_probe_port()

Sure, let me do that too.

FWIIW, I think it would be appropriate to put that change in a separate patch.

Fixing this and other similar changes in a different patch. Thanks

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@@ -2931,6 +2972,11 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
 		}
 
 		unregister_netdevice(ndev);
+		apc->indir_table_sz = 0;
+		kfree(apc->indir_table);
+		apc->indir_table = NULL;
+		kfree(apc->rxobj_table);
+		apc->rxobj_table = NULL;

The code to free and zero indir_table_sz and indir_table appears twice
in this patch. Perhaps a helper to do this, which would be the dual
of mana_rss_table_alloc is in order.

Makes sense, will change this too.

Thanks.