[PATCH 6.18 1031/1611] arm64/mm: Optimize TLB flush in unmap_hotplug_[pmd|pud]_range()

[PATCH 6.18 1031/1611] arm64/mm: Optimize TLB flush in unmap_hotplug_[pmd|pud]_range()

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Anshuman Khandual <anshuman.khandual@arm.com>

[ Upstream commit ff4c5a0de1f2ef7737a8688a86e19301e567020d ]

Commit 48478b9f7913 ("arm64/mm: Enable batched TLB flush in
unmap_hotplug_range") inadvertently introduced redundant TLB
invalidation when clearing a block entry, resulting in unnecessary
broadcast invalidation on CPUs without support for range-based
invalidation.

Re-introduce the old behaviour, along with some expanded comments to
help people working in this area next time around.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Closes: https://lore.kernel.org/all/b0d5836032ce3135bfc473f6bff791306d086925.camel@decadent.org.uk/
Fixes: 48478b9f7913 ("arm64/mm: Enable batched TLB flush in unmap_hotplug_range()")
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: Reword comments and commit message]
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/mm/mmu.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index ada93622ccf2c0..971cffdb8b48cc 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1515,7 +1515,13 @@ static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr,
 			if (free_mapped) {
 				/* CONT blocks are not supported in the vmemmap */
 				WARN_ON(pmd_cont(pmd));
-				flush_tlb_kernel_range(addr, addr + PMD_SIZE);
+				/*
+				 * Invalidating a block entry requires just
+				 * a single overlapping TLB invalidation,
+				 * so limit the range of the flush to a single
+				 * page.
+				 */
+				flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 				free_hotplug_page_range(pmd_page(pmd),
 							PMD_SIZE, altmap);
 			}
@@ -1545,7 +1551,8 @@ static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr,
 		if (pud_sect(pud)) {
 			pud_clear(pudp);
 			if (free_mapped) {
-				flush_tlb_kernel_range(addr, addr + PUD_SIZE);
+				/* See comment in unmap_hotplug_pmd_range(). */
+				flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 				free_hotplug_page_range(pud_page(pud),
 							PUD_SIZE, altmap);
 			}
-- 
2.53.0

[PATCH 6.18 1400/1611] net: ethernet: ti: icssg: guard PA stat lookups

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Philippe Schenker <philippe.schenker@impulsing.ch>

commit 27b9daba50609335db6ca81e4cccf50ded21ec76 upstream.

icssg_ndo_get_stats64() unconditionally calls emac_get_stat_by_name()
with FW PA stat names regardless of whether the PA stats block is
present on the hardware.  emac_get_stat_by_name() already guards the
PA stats lookup with `if (emac->prueth->pa_stats)`; when that pointer
is NULL the lookup falls through to netdev_err() and returns -EINVAL.
Because ndo_get_stats64 is polled regularly by the networking stack
this produces thousands of log entries of the form:

  icssg-prueth icssg1-eth end0: Invalid stats FW_RX_ERROR

A secondary consequence is that the int(-EINVAL) return value is
implicitly widened to a near-ULLONG_MAX unsigned value when accumulated
into the __u64 fields of rtnl_link_stats64, silently corrupting the
rx_errors, rx_dropped and tx_dropped counters reported by `ip -s link`.

Every other PA-aware code path in the driver is already guarded with
the same `if (emac->prueth->pa_stats)` check.  Apply the same guard
here.

Fixes: 0d15a26b247d ("net: ti: icssg-prueth: Add ICSSG FW Stats")
Signed-off-by: Philippe Schenker <philippe.schenker@impulsing.ch>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Cc: danishanwar@ti.com
Cc: rogerq@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260618093037.3448858-1-dev@pschenker.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/ti/icssg/icssg_common.c |   49 +++++++++++++++------------
 1 file changed, 28 insertions(+), 21 deletions(-)

--- a/drivers/net/ethernet/ti/icssg/icssg_common.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_common.c
@@ -1315,28 +1315,35 @@ void icssg_ndo_get_stats64(struct net_de
 	stats->rx_over_errors = emac_get_stat_by_name(emac, "rx_over_errors");
 	stats->multicast      = emac_get_stat_by_name(emac, "rx_multicast_frames");
 
-	stats->rx_errors  = ndev->stats.rx_errors +
-			    emac_get_stat_by_name(emac, "FW_RX_ERROR") +
-			    emac_get_stat_by_name(emac, "FW_RX_EOF_SHORT_FRMERR") +
-			    emac_get_stat_by_name(emac, "FW_RX_B0_DROP_EARLY_EOF") +
-			    emac_get_stat_by_name(emac, "FW_RX_EXP_FRAG_Q_DROP") +
-			    emac_get_stat_by_name(emac, "FW_RX_FIFO_OVERRUN");
-	stats->rx_dropped = ndev->stats.rx_dropped +
-			    emac_get_stat_by_name(emac, "FW_DROPPED_PKT") +
-			    emac_get_stat_by_name(emac, "FW_INF_PORT_DISABLED") +
-			    emac_get_stat_by_name(emac, "FW_INF_SAV") +
-			    emac_get_stat_by_name(emac, "FW_INF_SA_DL") +
-			    emac_get_stat_by_name(emac, "FW_INF_PORT_BLOCKED") +
-			    emac_get_stat_by_name(emac, "FW_INF_DROP_TAGGED") +
-			    emac_get_stat_by_name(emac, "FW_INF_DROP_PRIOTAGGED") +
-			    emac_get_stat_by_name(emac, "FW_INF_DROP_NOTAG") +
-			    emac_get_stat_by_name(emac, "FW_INF_DROP_NOTMEMBER");
+	stats->rx_errors  = ndev->stats.rx_errors;
+	stats->rx_dropped = ndev->stats.rx_dropped;
 	stats->tx_errors  = ndev->stats.tx_errors;
-	stats->tx_dropped = ndev->stats.tx_dropped +
-			    emac_get_stat_by_name(emac, "FW_RTU_PKT_DROP") +
-			    emac_get_stat_by_name(emac, "FW_TX_DROPPED_PACKET") +
-			    emac_get_stat_by_name(emac, "FW_TX_TS_DROPPED_PACKET") +
-			    emac_get_stat_by_name(emac, "FW_TX_JUMBO_FRM_CUTOFF");
+	stats->tx_dropped = ndev->stats.tx_dropped;
+
+	if (!emac->prueth->pa_stats)
+		return;
+
+	stats->rx_errors  +=
+			emac_get_stat_by_name(emac, "FW_RX_ERROR") +
+			emac_get_stat_by_name(emac, "FW_RX_EOF_SHORT_FRMERR") +
+			emac_get_stat_by_name(emac, "FW_RX_B0_DROP_EARLY_EOF") +
+			emac_get_stat_by_name(emac, "FW_RX_EXP_FRAG_Q_DROP") +
+			emac_get_stat_by_name(emac, "FW_RX_FIFO_OVERRUN");
+	stats->rx_dropped +=
+			emac_get_stat_by_name(emac, "FW_DROPPED_PKT") +
+			emac_get_stat_by_name(emac, "FW_INF_PORT_DISABLED") +
+			emac_get_stat_by_name(emac, "FW_INF_SAV") +
+			emac_get_stat_by_name(emac, "FW_INF_SA_DL") +
+			emac_get_stat_by_name(emac, "FW_INF_PORT_BLOCKED") +
+			emac_get_stat_by_name(emac, "FW_INF_DROP_TAGGED") +
+			emac_get_stat_by_name(emac, "FW_INF_DROP_PRIOTAGGED") +
+			emac_get_stat_by_name(emac, "FW_INF_DROP_NOTAG") +
+			emac_get_stat_by_name(emac, "FW_INF_DROP_NOTMEMBER");
+	stats->tx_dropped +=
+			emac_get_stat_by_name(emac, "FW_RTU_PKT_DROP") +
+			emac_get_stat_by_name(emac, "FW_TX_DROPPED_PACKET") +
+			emac_get_stat_by_name(emac, "FW_TX_TS_DROPPED_PACKET") +
+			emac_get_stat_by_name(emac, "FW_TX_JUMBO_FRM_CUTOFF");
 }
 EXPORT_SYMBOL_GPL(icssg_ndo_get_stats64);