From: Alex Elder <elder@linaro.org>
To: davem@davemloft.net, kuba@kernel.org
Cc: f.fainelli@gmail.com, bjorn.andersson@linaro.org,
evgreen@chromium.org, cpratapa@codeaurora.org,
subashab@codeaurora.org, elder@kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net-next v3 3/4] net: ipa: fix table alignment requirement
Date: Thu, 18 Mar 2021 13:59:29 -0500 [thread overview]
Message-ID: <20210318185930.891260-4-elder@linaro.org> (raw)
In-Reply-To: <20210318185930.891260-1-elder@linaro.org>
We currently have a build-time check to ensure that the minimum DMA
allocation alignment satisfies the constraint that IPA filter and
route tables must point to rules that are 128-byte aligned.
But what's really important is that the actual allocated DMA memory
has that alignment, even if the minimum is smaller than that.
Remove the BUILD_BUG_ON() call checking against minimim DMA alignment
and instead verify at rutime that the allocated memory is properly
aligned.
Signed-off-by: Alex Elder <elder@linaro.org>
---
drivers/net/ipa/ipa_table.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
index dd07fe9dd87a3..988f2c2886b95 100644
--- a/drivers/net/ipa/ipa_table.c
+++ b/drivers/net/ipa/ipa_table.c
@@ -118,14 +118,6 @@
/* Check things that can be validated at build time. */
static void ipa_table_validate_build(void)
{
- /* IPA hardware accesses memory 128 bytes at a time. Addresses
- * referred to by entries in filter and route tables must be
- * aligned on 128-byte byte boundaries. The only rule address
- * ever use is the "zero rule", and it's aligned at the base
- * of a coherent DMA allocation.
- */
- BUILD_BUG_ON(ARCH_DMA_MINALIGN % IPA_TABLE_ALIGN);
-
/* Filter and route tables contain DMA addresses that refer
* to filter or route rules. But the size of a table entry
* is 64 bits regardless of what the size of an AP DMA address
@@ -665,6 +657,18 @@ int ipa_table_init(struct ipa *ipa)
if (!virt)
return -ENOMEM;
+ /* We put the "zero rule" at the base of our table area. The IPA
+ * hardware requires rules to be aligned on a 128-byte boundary.
+ * Make sure the allocation satisfies this constraint.
+ */
+ if (addr % IPA_TABLE_ALIGN) {
+ dev_err(dev, "table address %pad not %u-byte aligned\n",
+ &addr, IPA_TABLE_ALIGN);
+ dma_free_coherent(dev, size, virt, addr);
+
+ return -ERANGE;
+ }
+
ipa->table_virt = virt;
ipa->table_addr = addr;
--
2.27.0
next prev parent reply other threads:[~2021-03-18 19:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 18:59 [PATCH net-next v3 0/4] net: ipa: support 32-bit targets Alex Elder
2021-03-18 18:59 ` [PATCH net-next v3 1/4] net: ipa: fix assumptions about DMA address size Alex Elder
2021-03-18 18:59 ` [PATCH net-next v3 2/4] net: ipa: use upper_32_bits() Alex Elder
2021-03-18 21:35 ` Florian Fainelli
2021-03-18 18:59 ` Alex Elder [this message]
2021-03-18 18:59 ` [PATCH net-next v3 4/4] net: ipa: relax 64-bit build requirement Alex Elder
2021-03-18 23:30 ` [PATCH net-next v3 0/4] net: ipa: support 32-bit targets patchwork-bot+netdevbpf
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