[PATCH net 0/4] net: ipa: a few bug fixes

[PATCH net 0/4] net: ipa: a few bug fixes

[Alex Elder]

This series fixes four minor bugs.  The first two are things that
sparse points out.  All four are very simple and each patch should
explain itself pretty well.

					-Alex

Alex Elder (4):
  net: ipa: add a missing __iomem attribute
  net: ipa: be explicit about endianness
  net: ipa: use the right accessor in ipa_endpoint_status_skip()
  net: ipa: fix two format specifier errors

 drivers/net/ipa/gsi.c          | 2 +-
 drivers/net/ipa/ipa_endpoint.c | 6 +++---
 drivers/net/ipa/ipa_mem.c      | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

-- 
2.27.0

[PATCH net 1/4] net: ipa: add a missing __iomem attribute

[Alex Elder]

The virt local variable in gsi_channel_state() does not have an
__iomem attribute but should.  Fix this.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 14d9a791924bf..e2e77f09077a9 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -440,7 +440,7 @@ static void gsi_evt_ring_de_alloc_command(struct gsi *gsi, u32 evt_ring_id)
 static enum gsi_channel_state gsi_channel_state(struct gsi_channel *channel)
 {
 	u32 channel_id = gsi_channel_id(channel);
-	void *virt = channel->gsi->virt;
+	void __iomem *virt = channel->gsi->virt;
 	u32 val;
 
 	val = ioread32(virt + GSI_CH_C_CNTXT_0_OFFSET(channel_id));
-- 
2.27.0

[PATCH net 2/4] net: ipa: be explicit about endianness

[Alex Elder]

Sparse warns that the assignment of the metadata mask for a QMAP
endpoint in ipa_endpoint_init_hdr_metadata_mask() is a bad
assignment.  We know we want the mask value to be big endian, even
though the value we write is in host byte order.  Use a __force
tag to indicate we really mean it.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_endpoint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index 9f4be9812a1f3..448d89da1e456 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -588,7 +588,7 @@ static void ipa_endpoint_init_hdr_metadata_mask(struct ipa_endpoint *endpoint)
 
 	/* Note that HDR_ENDIANNESS indicates big endian header fields */
 	if (endpoint->data->qmap)
-		val = cpu_to_be32(IPA_ENDPOINT_QMAP_METADATA_MASK);
+		val = (__force u32)cpu_to_be32(IPA_ENDPOINT_QMAP_METADATA_MASK);
 
 	iowrite32(val, endpoint->ipa->reg_virt + offset);
 }
-- 
2.27.0

[PATCH net 3/4] net: ipa: use the right accessor in ipa_endpoint_status_skip()

[Alex Elder]

When extracting the destination endpoint ID from the status in
ipa_endpoint_status_skip(), u32_get_bits() is used.  This happens to
work, but it's wrong: the structure field is only 8 bits wide
instead of 32.

Fix this by using u8_get_bits() to get the destination endpoint ID.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_endpoint.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index 448d89da1e456..612afece303f3 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -1164,8 +1164,8 @@ static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
 		return true;
 	if (!status->pkt_len)
 		return true;
-	endpoint_id = u32_get_bits(status->endp_dst_idx,
-				   IPA_STATUS_DST_IDX_FMASK);
+	endpoint_id = u8_get_bits(status->endp_dst_idx,
+				  IPA_STATUS_DST_IDX_FMASK);
 	if (endpoint_id != endpoint->endpoint_id)
 		return true;
 
-- 
2.27.0

[PATCH net 4/4] net: ipa: fix two format specifier errors

[Alex Elder]

Fix two format specifiers that used %lu for a size_t in "ipa_mem.c".

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_mem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
index 0cc3a3374caa2..f25029b9ec857 100644
--- a/drivers/net/ipa/ipa_mem.c
+++ b/drivers/net/ipa/ipa_mem.c
@@ -336,7 +336,7 @@ static void ipa_imem_exit(struct ipa *ipa)
 
 		size = iommu_unmap(domain, ipa->imem_iova, ipa->imem_size);
 		if (size != ipa->imem_size)
-			dev_warn(dev, "unmapped %zu IMEM bytes, expected %lu\n",
+			dev_warn(dev, "unmapped %zu IMEM bytes, expected %zu\n",
 				 size, ipa->imem_size);
 	} else {
 		dev_err(dev, "couldn't get IPA IOMMU domain for IMEM\n");
@@ -440,7 +440,7 @@ static void ipa_smem_exit(struct ipa *ipa)
 
 		size = iommu_unmap(domain, ipa->smem_iova, ipa->smem_size);
 		if (size != ipa->smem_size)
-			dev_warn(dev, "unmapped %zu SMEM bytes, expected %lu\n",
+			dev_warn(dev, "unmapped %zu SMEM bytes, expected %zu\n",
 				 size, ipa->smem_size);
 
 	} else {
-- 
2.27.0

Re: [PATCH net 3/4] net: ipa: use the right accessor in ipa_endpoint_status_skip()

[Amy Parker]

On Mon, Feb 1, 2021 at 3:32 PM Alex Elder <elder@linaro.org> wrote:
>
> When extracting the destination endpoint ID from the status in
> ipa_endpoint_status_skip(), u32_get_bits() is used.  This happens to
> work, but it's wrong: the structure field is only 8 bits wide
> instead of 32.
>
> Fix this by using u8_get_bits() to get the destination endpoint ID.

Isn't

>
> Signed-off-by: Alex Elder <elder@linaro.org>
> ---
>  drivers/net/ipa/ipa_endpoint.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
> index 448d89da1e456..612afece303f3 100644
> --- a/drivers/net/ipa/ipa_endpoint.c
> +++ b/drivers/net/ipa/ipa_endpoint.c
> @@ -1164,8 +1164,8 @@ static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
>                 return true;

A few lines above this, endpoint_id is initialized as u32. If we're
going for "correctness", endpoint_id should be a u8. But of course,
this would contrast with ipa_endpoint having it as a u32.


>         if (!status->pkt_len)
>                 return true;
> -       endpoint_id = u32_get_bits(status->endp_dst_idx,
> -                                  IPA_STATUS_DST_IDX_FMASK);
> +       endpoint_id = u8_get_bits(status->endp_dst_idx,
> +                                 IPA_STATUS_DST_IDX_FMASK);
>         if (endpoint_id != endpoint->endpoint_id)
>                 return true;
>
> --
> 2.27.0
>

As far as I see it, using u32_get_bits instead of u8_get_bits simply
eliminates confusion about the type of endpoint_id. Perhaps instead of
this patch, send a patch with a comment that while u32_get_bits is
used, the field is only 8 bits?

Best regards,
Amy Parker
(she/her/hers)

Re: [PATCH net 3/4] net: ipa: use the right accessor in ipa_endpoint_status_skip()

[Amy Parker]

On Mon, Feb 1, 2021 at 4:02 PM Amy Parker <enbyamy@gmail.com> wrote:

> > Fix this by using u8_get_bits() to get the destination endpoint ID.
>
> Isn't
>

Apologies about this - premature email sending. This was simply going
to be "Isn't endpoint_id u32?", which was addressed later anyways.

Best regards,
Amy Parker
(she/her/hers)

Re: [PATCH net 1/4] net: ipa: add a missing __iomem attribute

[Amy Parker]

On Mon, Feb 1, 2021 at 3:29 PM Alex Elder <elder@linaro.org> wrote:
>
> The virt local variable in gsi_channel_state() does not have an
> __iomem attribute but should.  Fix this.
>
> Signed-off-by: Alex Elder <elder@linaro.org>
> ---
>  drivers/net/ipa/gsi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
> index 14d9a791924bf..e2e77f09077a9 100644
> --- a/drivers/net/ipa/gsi.c
> +++ b/drivers/net/ipa/gsi.c
> @@ -440,7 +440,7 @@ static void gsi_evt_ring_de_alloc_command(struct gsi *gsi, u32 evt_ring_id)
>  static enum gsi_channel_state gsi_channel_state(struct gsi_channel *channel)
>  {
>         u32 channel_id = gsi_channel_id(channel);
> -       void *virt = channel->gsi->virt;
> +       void __iomem *virt = channel->gsi->virt;
>         u32 val;
>
>         val = ioread32(virt + GSI_CH_C_CNTXT_0_OFFSET(channel_id));
> --
> 2.27.0
>

Seems pretty straightforward to me, ioread32 expects an
__iomem-annotated pointer.

Reviewed-by: Amy Parker <enbyamy@gmail.com>

Re: [PATCH net 3/4] net: ipa: use the right accessor in ipa_endpoint_status_skip()

[Alex Elder]

On 2/1/21 6:02 PM, Amy Parker wrote:
> On Mon, Feb 1, 2021 at 3:32 PM Alex Elder <elder@linaro.org> wrote:
>>
>> When extracting the destination endpoint ID from the status in
>> ipa_endpoint_status_skip(), u32_get_bits() is used.  This happens to
>> work, but it's wrong: the structure field is only 8 bits wide
>> instead of 32.
>>
>> Fix this by using u8_get_bits() to get the destination endpoint ID.
> 
> Isn't

(I saw your second message.)

>> Signed-off-by: Alex Elder <elder@linaro.org>
>> ---
>>   drivers/net/ipa/ipa_endpoint.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
>> index 448d89da1e456..612afece303f3 100644
>> --- a/drivers/net/ipa/ipa_endpoint.c
>> +++ b/drivers/net/ipa/ipa_endpoint.c
>> @@ -1164,8 +1164,8 @@ static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
>>                  return true;
> 
> A few lines above this, endpoint_id is initialized as u32. If we're
> going for "correctness", endpoint_id should be a u8. But of course,
> this would contrast with ipa_endpoint having it as a u32.

You are correct, endpoint_id is *defined* as type u32.

But the issue here is that the field status->endp_dst_idx
has type u8.  u32_get_bits() assumes the field it is
passed has type u32; while u8_get_bits() takes a u8.

The return value of u8_get_bits() is u8, as you might
suspect.  The C standard guarantees that the u8 value
will be promoted to the u32 target type here.

>>          if (!status->pkt_len)
>>                  return true;
>> -       endpoint_id = u32_get_bits(status->endp_dst_idx,
>> -                                  IPA_STATUS_DST_IDX_FMASK);
>> +       endpoint_id = u8_get_bits(status->endp_dst_idx,
>> +                                 IPA_STATUS_DST_IDX_FMASK);
>>          if (endpoint_id != endpoint->endpoint_id)
>>                  return true;
>>
>> --
>> 2.27.0
>>
> 
> As far as I see it, using u32_get_bits instead of u8_get_bits simply
> eliminates confusion about the type of endpoint_id. Perhaps instead of
> this patch, send a patch with a comment that while u32_get_bits is
> used, the field is only 8 bits?

No.  We really want to extract a sub-field from the u8
value passed to u8_get_bits() (not u32_get_bits()).

Does that make sense?

					-Alex


> Best regards,
> Amy Parker
> (she/her/hers)
> 

Re: [PATCH net 3/4] net: ipa: use the right accessor in ipa_endpoint_status_skip()

[Amy Parker]

On Mon, Feb 1, 2021 at 4:15 PM Alex Elder <elder@linaro.org> wrote:
>
> On 2/1/21 6:02 PM, Amy Parker wrote:
> > On Mon, Feb 1, 2021 at 3:32 PM Alex Elder <elder@linaro.org> wrote:
> >>
> >> When extracting the destination endpoint ID from the status in
> >> ipa_endpoint_status_skip(), u32_get_bits() is used.  This happens to
> >> work, but it's wrong: the structure field is only 8 bits wide
> >> instead of 32.
> >>
> >> Fix this by using u8_get_bits() to get the destination endpoint ID.
> >
> > Isn't
>
> (I saw your second message.)
>
> >> Signed-off-by: Alex Elder <elder@linaro.org>
> >> ---
> >>   drivers/net/ipa/ipa_endpoint.c | 4 ++--
> >>   1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
> >> index 448d89da1e456..612afece303f3 100644
> >> --- a/drivers/net/ipa/ipa_endpoint.c
> >> +++ b/drivers/net/ipa/ipa_endpoint.c
> >> @@ -1164,8 +1164,8 @@ static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
> >>                  return true;
> >
> > A few lines above this, endpoint_id is initialized as u32. If we're
> > going for "correctness", endpoint_id should be a u8. But of course,
> > this would contrast with ipa_endpoint having it as a u32.
>
> You are correct, endpoint_id is *defined* as type u32.
>
> But the issue here is that the field status->endp_dst_idx
> has type u8.  u32_get_bits() assumes the field it is
> passed has type u32; while u8_get_bits() takes a u8.

Ah, missed that bit. Thanks for clarifying.

>
> The return value of u8_get_bits() is u8, as you might
> suspect.  The C standard guarantees that the u8 value
> will be promoted to the u32 target type here.

Yes, it does, and so it wouldn't be a theoretical issue - just an
issue of developer confusion at first when working with it. But the
above outlined point of the types taken is more important.

>
> >>          if (!status->pkt_len)
> >>                  return true;
> >> -       endpoint_id = u32_get_bits(status->endp_dst_idx,
> >> -                                  IPA_STATUS_DST_IDX_FMASK);
> >> +       endpoint_id = u8_get_bits(status->endp_dst_idx,
> >> +                                 IPA_STATUS_DST_IDX_FMASK);
> >>          if (endpoint_id != endpoint->endpoint_id)
> >>                  return true;
> >>
> >> --
> >> 2.27.0
> >>
> >
> > As far as I see it, using u32_get_bits instead of u8_get_bits simply
> > eliminates confusion about the type of endpoint_id. Perhaps instead of
> > this patch, send a patch with a comment that while u32_get_bits is
> > used, the field is only 8 bits?
>
> No.  We really want to extract a sub-field from the u8
> value passed to u8_get_bits() (not u32_get_bits()).
>
> Does that make sense?
>
>                                         -Alex

Yes, it does. Thank you.

Best regards,
Amy Parker
(she/her/hers)

Re: [PATCH net 0/4] net: ipa: a few bug fixes

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Mon,  1 Feb 2021 17:26:05 -0600 you wrote:
> This series fixes four minor bugs.  The first two are things that
> sparse points out.  All four are very simple and each patch should
> explain itself pretty well.
> 
> 					-Alex
> 
> Alex Elder (4):
>   net: ipa: add a missing __iomem attribute
>   net: ipa: be explicit about endianness
>   net: ipa: use the right accessor in ipa_endpoint_status_skip()
>   net: ipa: fix two format specifier errors
> 
> [...]

Here is the summary with links:
  - [net,1/4] net: ipa: add a missing __iomem attribute
    https://git.kernel.org/netdev/net/c/e6cdd6d80bae
  - [net,2/4] net: ipa: be explicit about endianness
    https://git.kernel.org/netdev/net/c/088f8a2396d8
  - [net,3/4] net: ipa: use the right accessor in ipa_endpoint_status_skip()
    https://git.kernel.org/netdev/net/c/c13899f18728
  - [net,4/4] net: ipa: fix two format specifier errors
    https://git.kernel.org/netdev/net/c/113b6ea09ccd

You are awesome, thank you!
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