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From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Elliot Berman <quic_eberman@quicinc.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Guru Das Srinagesh <quic_gurus@quicinc.com>,
	Andrew Halaney <ahalaney@redhat.com>,
	Maximilian Luz <luzmaximilian@gmail.com>,
	Alex Elder <elder@linaro.org>,
	Srini Kandagatla <srinivas.kandagatla@linaro.org>,
	Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kernel@quicinc.com,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>,
	Deepti Jaggi <quic_djaggi@quicinc.com>
Subject: [PATCH v9 05/13] firmware: qcom: scm: make qcom_scm_ice_set_key() use the TZ allocator
Date: Mon, 25 Mar 2024 11:03:51 +0100
Message-Id: <20240325100359.17001-6-brgl@bgdev.pl>
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From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Let's use the new TZ memory allocator to obtain a buffer for this call
instead of using dma_alloc_coherent().

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com> # sc8280xp-lenovo-thinkpad-x13s
Tested-by: Deepti Jaggi <quic_djaggi@quicinc.com> #sa8775p-ride
Reviewed-by: Elliot Berman <quic_eberman@quicinc.com>
---
 drivers/firmware/qcom/qcom_scm.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index cd47389ac80c..de66319cbfb9 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -1200,32 +1200,21 @@ int qcom_scm_ice_set_key(u32 index, const u8 *key, u32 key_size,
 		.args[4] = data_unit_size,
 		.owner = ARM_SMCCC_OWNER_SIP,
 	};
-	void *keybuf;
-	dma_addr_t key_phys;
+
 	int ret;
 
-	/*
-	 * 'key' may point to vmalloc()'ed memory, but we need to pass a
-	 * physical address that's been properly flushed.  The sanctioned way to
-	 * do this is by using the DMA API.  But as is best practice for crypto
-	 * keys, we also must wipe the key after use.  This makes kmemdup() +
-	 * dma_map_single() not clearly correct, since the DMA API can use
-	 * bounce buffers.  Instead, just use dma_alloc_coherent().  Programming
-	 * keys is normally rare and thus not performance-critical.
-	 */
-
-	keybuf = dma_alloc_coherent(__scm->dev, key_size, &key_phys,
-				    GFP_KERNEL);
+	void *keybuf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool,
+							   key_size,
+							   GFP_KERNEL);
 	if (!keybuf)
 		return -ENOMEM;
 	memcpy(keybuf, key, key_size);
-	desc.args[1] = key_phys;
+	desc.args[1] = qcom_tzmem_to_phys(keybuf);
 
 	ret = qcom_scm_call(__scm->dev, &desc, NULL);
 
 	memzero_explicit(keybuf, key_size);
 
-	dma_free_coherent(__scm->dev, key_size, keybuf, key_phys);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(qcom_scm_ice_set_key);
-- 
2.40.1