[PATCH 6.6 003/273] arm64/mm: Ensure adequate HUGE_MAX_HSTATE

[PATCH 6.6 003/273] arm64/mm: Ensure adequate HUGE_MAX_HSTATE

[Greg Kroah-Hartman]

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

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

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

[ Upstream commit 1e5823c8e86de83a43d59a522b4de29066d3b306 ]

This asserts that HUGE_MAX_HSTATE is sufficient enough preventing potential
hugetlb_max_hstate runtime overflow in hugetlb_add_hstate() thus triggering
a BUG_ON() there after.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20241202064407.53807-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/mm/hugetlbpage.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 13fd592228b18..a5e1588780b2c 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -526,6 +526,18 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 
 static int __init hugetlbpage_init(void)
 {
+	/*
+	 * HugeTLB pages are supported on maximum four page table
+	 * levels (PUD, CONT PMD, PMD, CONT PTE) for a given base
+	 * page size, corresponding to hugetlb_add_hstate() calls
+	 * here.
+	 *
+	 * HUGE_MAX_HSTATE should at least match maximum supported
+	 * HugeTLB page sizes on the platform. Any new addition to
+	 * supported HugeTLB page sizes will also require changing
+	 * HUGE_MAX_HSTATE as well.
+	 */
+	BUILD_BUG_ON(HUGE_MAX_HSTATE < 4);
 	if (pud_sect_supported())
 		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
 
-- 
2.39.5

[PATCH 6.6 092/273] drm/rockchip: cdn-dp: Use drm_connector_helper_hpd_irq_event()

[Greg Kroah-Hartman]

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

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

From: Thomas Zimmermann <tzimmermann@suse.de>

commit 666e1960464140cc4bc9203c203097e70b54c95a upstream.

The code for detecting and updating the connector status in
cdn_dp_pd_event_work() has a number of problems.

- It does not aquire the locks to call the detect helper and update
the connector status. These are struct drm_mode_config.connection_mutex
and struct drm_mode_config.mutex.

- It does not use drm_helper_probe_detect(), which helps with the
details of locking and detection.

- It uses the connector's status field to determine a change to
the connector status. The epoch_counter field is the correct one. The
field signals a change even if the connector status' value did not
change.

Replace the code with a call to drm_connector_helper_hpd_irq_event(),
which fixes all these problems.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 81632df69772 ("drm/rockchip: cdn-dp: do not use drm_helper_hpd_irq_event")
Cc: Chris Zhong <zyw@rock-chips.com>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Andy Yan <andy.yan@rock-chips.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241105133848.480407-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/rockchip/cdn-dp-core.c |    9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -946,9 +946,6 @@ static void cdn_dp_pd_event_work(struct
 {
 	struct cdn_dp_device *dp = container_of(work, struct cdn_dp_device,
 						event_work);
-	struct drm_connector *connector = &dp->connector;
-	enum drm_connector_status old_status;
-
 	int ret;
 
 	mutex_lock(&dp->lock);
@@ -1010,11 +1007,7 @@ static void cdn_dp_pd_event_work(struct
 
 out:
 	mutex_unlock(&dp->lock);
-
-	old_status = connector->status;
-	connector->status = connector->funcs->detect(connector, false);
-	if (old_status != connector->status)
-		drm_kms_helper_hotplug_event(dp->drm_dev);
+	drm_connector_helper_hpd_irq_event(&dp->connector);
 }
 
 static int cdn_dp_pd_event(struct notifier_block *nb,