[PATCH AUTOSEL 4.19 1/3] Drivers: hv: Never allocate anything besides framebuffer from framebuffer memory region

[PATCH AUTOSEL 4.19 1/3] Drivers: hv: Never allocate anything besides framebuffer from framebuffer memory region

[Sasha Levin]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

[ Upstream commit f0880e2cb7e1f8039a048fdd01ce45ab77247221 ]

Passed through PCI device sometimes misbehave on Gen1 VMs when Hyper-V
DRM driver is also loaded. Looking at IOMEM assignment, we can see e.g.

$ cat /proc/iomem
...
f8000000-fffbffff : PCI Bus 0000:00
  f8000000-fbffffff : 0000:00:08.0
    f8000000-f8001fff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe
...
fe0000000-fffffffff : PCI Bus 0000:00
  fe0000000-fe07fffff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe
    fe0000000-fe07fffff : 2ba2:00:02.0
      fe0000000-fe07fffff : mlx4_core

the interesting part is the 'f8000000' region as it is actually the
VM's framebuffer:

$ lspci -v
...
0000:00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual VGA (prog-if 00 [VGA controller])
	Flags: bus master, fast devsel, latency 0, IRQ 11
	Memory at f8000000 (32-bit, non-prefetchable) [size=64M]
...

 hv_vmbus: registering driver hyperv_drm
 hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] Synthvid Version major 3, minor 5
 hyperv_drm 0000:00:08.0: vgaarb: deactivate vga console
 hyperv_drm 0000:00:08.0: BAR 0: can't reserve [mem 0xf8000000-0xfbffffff]
 hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] Cannot request framebuffer, boot fb still active?

Note: "Cannot request framebuffer" is not a fatal error in
hyperv_setup_gen1() as the code assumes there's some other framebuffer
device there but we actually have some other PCI device (mlx4 in this
case) config space there!

The problem appears to be that vmbus_allocate_mmio() can use dedicated
framebuffer region to serve any MMIO request from any device. The
semantics one might assume of a parameter named "fb_overlap_ok"
aren't implemented because !fb_overlap_ok essentially has no effect.
The existing semantics are really "prefer_fb_overlap". This patch
implements the expected and needed semantics, which is to not allocate
from the frame buffer space when !fb_overlap_ok.

Note, Gen2 VMs are usually unaffected by the issue because
framebuffer region is already taken by EFI fb (in case kernel supports
it) but Gen1 VMs may have this region unclaimed by the time Hyper-V PCI
pass-through driver tries allocating MMIO space if Hyper-V DRM/FB drivers
load after it. Devices can be brought up in any sequence so let's
resolve the issue by always ignoring 'fb_mmio' region for non-FB
requests, even if the region is unclaimed.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20220827130345.1320254-4-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hv/vmbus_drv.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index fca092cfe200..9cbe0b00ebf7 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1846,7 +1846,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 			bool fb_overlap_ok)
 {
 	struct resource *iter, *shadow;
-	resource_size_t range_min, range_max, start;
+	resource_size_t range_min, range_max, start, end;
 	const char *dev_n = dev_name(&device_obj->device);
 	int retval;
 
@@ -1881,6 +1881,14 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 		range_max = iter->end;
 		start = (range_min + align - 1) & ~(align - 1);
 		for (; start + size - 1 <= range_max; start += align) {
+			end = start + size - 1;
+
+			/* Skip the whole fb_mmio region if not fb_overlap_ok */
+			if (!fb_overlap_ok && fb_mmio &&
+			    (((start >= fb_mmio->start) && (start <= fb_mmio->end)) ||
+			     ((end >= fb_mmio->start) && (end <= fb_mmio->end))))
+				continue;
+
 			shadow = __request_region(iter, start, size, NULL,
 						  IORESOURCE_BUSY);
 			if (!shadow)
-- 
2.35.1

[PATCH AUTOSEL 4.19 2/3] drm/amd/display: Limit user regamma to a valid value

[Sasha Levin]

From: Yao Wang1 <Yao.Wang1@amd.com>

[ Upstream commit 3601d620f22e37740cf73f8278eabf9f2aa19eb7 ]

[Why]
For HDR mode, we get total 512 tf_point and after switching to SDR mode
we actually get 400 tf_point and the rest of points(401~512) still use
dirty value from HDR mode. We should limit the rest of the points to max
value.

[How]
Limit the value when coordinates_x.x > 1, just like what we do in
translate_from_linear_space for other re-gamma build paths.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Yao Wang1 <Yao.Wang1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
index 11ea1a0e629b..4e866317ec25 100644
--- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
+++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
@@ -1206,6 +1206,7 @@ static void interpolate_user_regamma(uint32_t hw_points_num,
 	struct fixed31_32 lut2;
 	struct fixed31_32 delta_lut;
 	struct fixed31_32 delta_index;
+	const struct fixed31_32 one = dc_fixpt_from_int(1);
 
 	i = 0;
 	/* fixed_pt library has problems handling too small values */
@@ -1234,6 +1235,9 @@ static void interpolate_user_regamma(uint32_t hw_points_num,
 			} else
 				hw_x = coordinates_x[i].x;
 
+			if (dc_fixpt_le(one, hw_x))
+				hw_x = one;
+
 			norm_x = dc_fixpt_mul(norm_factor, hw_x);
 			index = dc_fixpt_floor(norm_x);
 			if (index < 0 || index > 255)
-- 
2.35.1

[PATCH AUTOSEL 4.19 3/3] drm/rockchip: Fix return type of cdn_dp_connector_mode_valid

[Sasha Levin]

From: Nathan Huckleberry <nhuck@google.com>

[ Upstream commit b0b9408f132623dc88e78adb5282f74e4b64bb57 ]

The mode_valid field in drm_connector_helper_funcs is expected to be of
type:
enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
				     struct drm_display_mode *mode);

The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition.

The return type of cdn_dp_connector_mode_valid should be changed from
int to enum drm_mode_status.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@lists.linux.dev
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220913205555.155149-1-nhuck@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/rockchip/cdn-dp-core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index 3feab563e50a..3f992e5a75c9 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -284,8 +284,9 @@ static int cdn_dp_connector_get_modes(struct drm_connector *connector)
 	return ret;
 }
 
-static int cdn_dp_connector_mode_valid(struct drm_connector *connector,
-				       struct drm_display_mode *mode)
+static enum drm_mode_status
+cdn_dp_connector_mode_valid(struct drm_connector *connector,
+			    struct drm_display_mode *mode)
 {
 	struct cdn_dp_device *dp = connector_to_dp(connector);
 	struct drm_display_info *display_info = &dp->connector.display_info;
-- 
2.35.1