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From:   Alex Elder <elder@linaro.org>
To:     davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com
Cc:     mka@chromium.org, evgreen@chromium.org, bjorn.andersson@linaro.org,
        quic_cpratapa@quicinc.com, quic_avuyyuru@quicinc.com,
        quic_jponduru@quicinc.com, quic_subashab@quicinc.com,
        elder@kernel.org, netdev@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net] net: ipa: don't assume SMEM is page-aligned
Date:   Thu, 18 Aug 2022 08:42:05 -0500
Message-Id: <20220818134206.567618-1-elder@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In ipa_smem_init(), a Qualcomm SMEM region is allocated (if needed)
and then its virtual address is fetched using qcom_smem_get().  The
physical address associated with that region is also fetched.

The physical address is adjusted so that it is page-aligned, and an
attempt is made to update the size of the region to compensate for
any non-zero adjustment.

But that adjustment isn't done properly.  The physical address is
aligned twice, and as a result the size is never actually adjusted.

Fix this by *not* aligning the "addr" local variable, and instead
making the "phys" local variable be the adjusted "addr" value.

Fixes: a0036bb413d5b ("net: ipa: define SMEM memory region for IPA")
Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_mem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
index 1e9eae208e44f..53a1dbeaffa6d 100644
--- a/drivers/net/ipa/ipa_mem.c
+++ b/drivers/net/ipa/ipa_mem.c
@@ -568,7 +568,7 @@ static int ipa_smem_init(struct ipa *ipa, u32 item, size_t size)
 	}
 
 	/* Align the address down and the size up to a page boundary */
-	addr = qcom_smem_virt_to_phys(virt) & PAGE_MASK;
+	addr = qcom_smem_virt_to_phys(virt);
 	phys = addr & PAGE_MASK;
 	size = PAGE_ALIGN(size + addr - phys);
 	iova = phys;	/* We just want a direct mapping */
-- 
2.34.1