diff mbox series

[v2,net,5/5] net: ipa: avoid going past end of resource group array

Message ID 20201028194148.6659-6-elder@linaro.org
State Superseded
Headers show
Series net: ipa: minor bug fixes | expand

Commit Message

Alex Elder Oct. 28, 2020, 7:41 p.m. UTC 
The minimum and maximum limits for resources assigned to a given
resource group are programmed in pairs, with the limits for two
groups set in a single register.

If the number of supported resource groups is odd, only half of the
register that defines these limits is valid for the last group; that
group has no second group in the pair.

Currently we ignore this constraint, and it turns out to be harmless,
but it is not guaranteed to be.  This patch addresses that, and adds
support for programming the 5th resource group's limits.

Rework how the resource group limit registers are programmed by
having a single function program all group pairs rather than having
one function program each pair.  Add the programming of the 4-5
resource group pair limits to this function.  If a resource group is
not supported, pass a null pointer to ipa_resource_config_common()
for that group and have that function write zeroes in that case.

Fixes: cdf2e9419dd91 ("soc: qcom: ipa: main code")
Tested-by: Sujit Kautkar <sujitka@chromium.org>
Signed-off-by: Alex Elder <elder@linaro.org>
---
v2: Fixed comparison error identified by Willem de Bruijn.

 drivers/net/ipa/ipa_main.c | 89 +++++++++++++++++++++++---------------
 1 file changed, 53 insertions(+), 36 deletions(-)

Comments

Willem de Bruijn Oct. 28, 2020, 8:37 p.m. UTC | #1 
On Wed, Oct 28, 2020 at 3:42 PM Alex Elder <elder@linaro.org> wrote:
>

> The minimum and maximum limits for resources assigned to a given

> resource group are programmed in pairs, with the limits for two

> groups set in a single register.

>

> If the number of supported resource groups is odd, only half of the

> register that defines these limits is valid for the last group; that

> group has no second group in the pair.

>

> Currently we ignore this constraint, and it turns out to be harmless,

> but it is not guaranteed to be.  This patch addresses that, and adds

> support for programming the 5th resource group's limits.

>

> Rework how the resource group limit registers are programmed by

> having a single function program all group pairs rather than having

> one function program each pair.  Add the programming of the 4-5

> resource group pair limits to this function.  If a resource group is

> not supported, pass a null pointer to ipa_resource_config_common()

> for that group and have that function write zeroes in that case.

>

> Fixes: cdf2e9419dd91 ("soc: qcom: ipa: main code")

> Tested-by: Sujit Kautkar <sujitka@chromium.org>

> Signed-off-by: Alex Elder <elder@linaro.org>


Acked-by: Willem de Bruijn <willemb@google.com>
diff mbox series

Patch

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 74b1e15ebd6b2..f4dd14d9550fe 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -370,8 +370,11 @@  static bool ipa_resource_limits_valid(struct ipa *ipa,
 	u32 i;
 	u32 j;
 
+	/* We program at most 6 source or destination resource group limits */
+	BUILD_BUG_ON(IPA_RESOURCE_GROUP_SRC_MAX > 6);
+
 	group_count = ipa_resource_group_src_count(ipa->version);
-	if (!group_count)
+	if (!group_count || group_count > IPA_RESOURCE_GROUP_SRC_MAX)
 		return false;
 
 	/* Return an error if a non-zero resource limit is specified
@@ -387,7 +390,7 @@  static bool ipa_resource_limits_valid(struct ipa *ipa,
 	}
 
 	group_count = ipa_resource_group_dst_count(ipa->version);
-	if (!group_count)
+	if (!group_count || group_count > IPA_RESOURCE_GROUP_DST_MAX)
 		return false;
 
 	for (i = 0; i < data->resource_dst_count; i++) {
@@ -421,46 +424,64 @@  ipa_resource_config_common(struct ipa *ipa, u32 offset,
 
 	val = u32_encode_bits(xlimits->min, X_MIN_LIM_FMASK);
 	val |= u32_encode_bits(xlimits->max, X_MAX_LIM_FMASK);
-	val |= u32_encode_bits(ylimits->min, Y_MIN_LIM_FMASK);
-	val |= u32_encode_bits(ylimits->max, Y_MAX_LIM_FMASK);
+	if (ylimits) {
+		val |= u32_encode_bits(ylimits->min, Y_MIN_LIM_FMASK);
+		val |= u32_encode_bits(ylimits->max, Y_MAX_LIM_FMASK);
+	}
 
 	iowrite32(val, ipa->reg_virt + offset);
 }
 
-static void ipa_resource_config_src_01(struct ipa *ipa,
-				       const struct ipa_resource_src *resource)
+static void ipa_resource_config_src(struct ipa *ipa,
+				    const struct ipa_resource_src *resource)
 {
-	u32 offset = IPA_REG_SRC_RSRC_GRP_01_RSRC_TYPE_N_OFFSET(resource->type);
+	u32 group_count = ipa_resource_group_src_count(ipa->version);
+	const struct ipa_resource_limits *ylimits;
+	u32 offset;
 
-	ipa_resource_config_common(ipa, offset,
-				   &resource->limits[0], &resource->limits[1]);
-}
+	offset = IPA_REG_SRC_RSRC_GRP_01_RSRC_TYPE_N_OFFSET(resource->type);
+	ylimits = group_count == 1 ? NULL : &resource->limits[1];
+	ipa_resource_config_common(ipa, offset, &resource->limits[0], ylimits);
 
-static void ipa_resource_config_src_23(struct ipa *ipa,
-				       const struct ipa_resource_src *resource)
-{
-	u32 offset = IPA_REG_SRC_RSRC_GRP_23_RSRC_TYPE_N_OFFSET(resource->type);
+	if (group_count < 2)
+		return;
 
-	ipa_resource_config_common(ipa, offset,
-				   &resource->limits[2], &resource->limits[3]);
-}
+	offset = IPA_REG_SRC_RSRC_GRP_23_RSRC_TYPE_N_OFFSET(resource->type);
+	ylimits = group_count == 3 ? NULL : &resource->limits[3];
+	ipa_resource_config_common(ipa, offset, &resource->limits[2], ylimits);
 
-static void ipa_resource_config_dst_01(struct ipa *ipa,
-				       const struct ipa_resource_dst *resource)
-{
-	u32 offset = IPA_REG_DST_RSRC_GRP_01_RSRC_TYPE_N_OFFSET(resource->type);
+	if (group_count < 4)
+		return;
 
-	ipa_resource_config_common(ipa, offset,
-				   &resource->limits[0], &resource->limits[1]);
+	offset = IPA_REG_SRC_RSRC_GRP_45_RSRC_TYPE_N_OFFSET(resource->type);
+	ylimits = group_count == 5 ? NULL : &resource->limits[5];
+	ipa_resource_config_common(ipa, offset, &resource->limits[4], ylimits);
 }
 
-static void ipa_resource_config_dst_23(struct ipa *ipa,
-				       const struct ipa_resource_dst *resource)
+static void ipa_resource_config_dst(struct ipa *ipa,
+				    const struct ipa_resource_dst *resource)
 {
-	u32 offset = IPA_REG_DST_RSRC_GRP_23_RSRC_TYPE_N_OFFSET(resource->type);
+	u32 group_count = ipa_resource_group_dst_count(ipa->version);
+	const struct ipa_resource_limits *ylimits;
+	u32 offset;
+
+	offset = IPA_REG_DST_RSRC_GRP_01_RSRC_TYPE_N_OFFSET(resource->type);
+	ylimits = group_count == 1 ? NULL : &resource->limits[1];
+	ipa_resource_config_common(ipa, offset, &resource->limits[0], ylimits);
+
+	if (group_count < 2)
+		return;
+
+	offset = IPA_REG_DST_RSRC_GRP_23_RSRC_TYPE_N_OFFSET(resource->type);
+	ylimits = group_count == 3 ? NULL : &resource->limits[3];
+	ipa_resource_config_common(ipa, offset, &resource->limits[2], ylimits);
+
+	if (group_count < 4)
+		return;
 
-	ipa_resource_config_common(ipa, offset,
-				   &resource->limits[2], &resource->limits[3]);
+	offset = IPA_REG_DST_RSRC_GRP_45_RSRC_TYPE_N_OFFSET(resource->type);
+	ylimits = group_count == 5 ? NULL : &resource->limits[5];
+	ipa_resource_config_common(ipa, offset, &resource->limits[4], ylimits);
 }
 
 static int
@@ -471,15 +492,11 @@  ipa_resource_config(struct ipa *ipa, const struct ipa_resource_data *data)
 	if (!ipa_resource_limits_valid(ipa, data))
 		return -EINVAL;
 
-	for (i = 0; i < data->resource_src_count; i++) {
-		ipa_resource_config_src_01(ipa, &data->resource_src[i]);
-		ipa_resource_config_src_23(ipa, &data->resource_src[i]);
-	}
+	for (i = 0; i < data->resource_src_count; i++)
+		ipa_resource_config_src(ipa, data->resource_src);
 
-	for (i = 0; i < data->resource_dst_count; i++) {
-		ipa_resource_config_dst_01(ipa, &data->resource_dst[i]);
-		ipa_resource_config_dst_23(ipa, &data->resource_dst[i]);
-	}
+	for (i = 0; i < data->resource_dst_count; i++)
+		ipa_resource_config_dst(ipa, data->resource_dst);
 
 	return 0;
 }