bnxt: fix bnxt_get_avail_msix() returning negative values

Current net-next/main does not boot for older chipsets e.g. Stratus.

Sample dmesg:
[   11.368315] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): Able to reserve only 0 out of 9 requested RX rings
[   11.390181] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): Unable to reserve tx rings
[   11.438780] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): 2nd rings reservation failed.
[   11.487559] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): Not enough rings available.
[   11.506012] bnxt_en 0000:02:00.0: probe with driver bnxt_en failed with error -12

This is caused by bnxt_get_avail_msix() returning a negative value for
these chipsets not using the new resource manager i.e. !BNXT_NEW_RM.
This in turn causes hwr.cp in __bnxt_reserve_rings() to be set to 0.

In the current call stack, __bnxt_reserve_rings() is called from
bnxt_set_dflt_rings() before bnxt_init_int_mode(). Therefore,
bp->total_irqs is always 0 and for !BNXT_NEW_RM bnxt_get_avail_msix()
always returns a negative number.

Historically, MSIX vectors were requested by the RoCE driver during
run-time and bnxt_get_avail_msix() was used for this purpose. Today,
RoCE MSIX vectors are statically allocated. bnxt_get_avail_msix() should
only be called for the BNXT_NEW_RM() case to reserve the MSIX ahead of
time for RoCE use.

bnxt_get_avail_msix() is also be simplified to handle the BNXT_NEW_RM()
case only.

Fixes: d630624ebd70 ("bnxt_en: Utilize ulp client resources if RoCE is not registered")
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20240502203757.3761827-1-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 78ba383d2fa064c03c8deb53804fe7b801538da7..0d1ed6e5dfbd286499c0d74cf571e2d77fbe767b 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -7469,6 +7469,8 @@ static bool bnxt_rings_ok(struct bnxt *bp, struct bnxt_hw_rings *hwr)
               hwr->stat && (hwr->cp_p5 || !(bp->flags & BNXT_FLAG_CHIP_P5_PLUS));
 }
 
+static int bnxt_get_avail_msix(struct bnxt *bp, int num);
+
 static int __bnxt_reserve_rings(struct bnxt *bp)
 {
        struct bnxt_hw_rings hwr = {0};
@@ -7481,7 +7483,7 @@ static int __bnxt_reserve_rings(struct bnxt *bp)
        if (!bnxt_need_reserve_rings(bp))
                return 0;
 
-       if (!bnxt_ulp_registered(bp->edev)) {
+       if (BNXT_NEW_RM(bp) && !bnxt_ulp_registered(bp->edev)) {
                ulp_msix = bnxt_get_avail_msix(bp, bp->ulp_num_msix_want);
                if (!ulp_msix)
                        bnxt_set_ulp_stat_ctxs(bp, 0);
@@ -10484,19 +10486,10 @@ unsigned int bnxt_get_avail_stat_ctxs_for_en(struct bnxt *bp)
        return bnxt_get_max_func_stat_ctxs(bp) - bnxt_get_func_stat_ctxs(bp);
 }
 
-int bnxt_get_avail_msix(struct bnxt *bp, int num)
+static int bnxt_get_avail_msix(struct bnxt *bp, int num)
 {
-       int max_cp = bnxt_get_max_func_cp_rings(bp);
        int max_irq = bnxt_get_max_func_irqs(bp);
        int total_req = bp->cp_nr_rings + num;
-       int max_idx, avail_msix;
-
-       max_idx = bp->total_irqs;
-       if (!(bp->flags & BNXT_FLAG_CHIP_P5_PLUS))
-               max_idx = min_t(int, bp->total_irqs, max_cp);
-       avail_msix = max_idx - bp->cp_nr_rings;
-       if (!BNXT_NEW_RM(bp) || avail_msix >= num)
-               return avail_msix;
 
        if (max_irq < total_req) {
                num = max_irq - bp->cp_nr_rings;
@@ -10629,7 +10622,7 @@ int bnxt_reserve_rings(struct bnxt *bp, bool irq_re_init)
        if (!bnxt_need_reserve_rings(bp))
                return 0;
 
-       if (!bnxt_ulp_registered(bp->edev)) {
+       if (BNXT_NEW_RM(bp) && !bnxt_ulp_registered(bp->edev)) {
                int ulp_msix = bnxt_get_avail_msix(bp, bp->ulp_num_msix_want);
 
                if (ulp_msix > bp->ulp_num_msix_want)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 34d82aaa49edd7eeead93ad2f311cb08d823222b..656ab81c0272d93d435ea6161f22e3a04c5def74 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -2738,7 +2738,6 @@ unsigned int bnxt_get_max_func_stat_ctxs(struct bnxt *bp);
 unsigned int bnxt_get_avail_stat_ctxs_for_en(struct bnxt *bp);
 unsigned int bnxt_get_max_func_cp_rings(struct bnxt *bp);
 unsigned int bnxt_get_avail_cp_rings_for_en(struct bnxt *bp);
-int bnxt_get_avail_msix(struct bnxt *bp, int num);
 int bnxt_reserve_rings(struct bnxt *bp, bool irq_re_init);
 void bnxt_tx_disable(struct bnxt *bp);
 void bnxt_tx_enable(struct bnxt *bp);