Merge tag 'qcom-drivers-fixes-for-6.9' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux into for-next

Qualcomm driver fix for v6.9

This reworks the memory layout of the argument buffers passed to trusted
applications in QSEECOM, to avoid failures and system crashes.

* tag 'qcom-drivers-fixes-for-6.9' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux:
  firmware: qcom: uefisecapp: Fix memory related IO errors and crashes

Link: https://lore.kernel.org/r/20240420163816.1133528-1-andersson@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 56 insertions, 9 deletions

diff --git a/include/linux/firmware/qcom/qcom_qseecom.h b/include/linux/firmware/qcom/qcom_qseecom.h
index 5c28298a98be..366243ee9609 100644
--- a/include/linux/firmware/qcom/qcom_qseecom.h
+++ b/include/linux/firmware/qcom/qcom_qseecom.h
@@ -10,6 +10,7 @@
 #define __QCOM_QSEECOM_H
 
 #include <linux/auxiliary_bus.h>
+#include <linux/dma-mapping.h>
 #include <linux/types.h>
 
 #include <linux/firmware/qcom/qcom_scm.h>
@@ -25,11 +26,56 @@ struct qseecom_client {
 };
 
 /**
+ * qseecom_scm_dev() - Get the SCM device associated with the QSEECOM client.
+ * @client: The QSEECOM client device.
+ *
+ * Returns the SCM device under which the provided QSEECOM client device
+ * operates. This function is intended to be used for DMA allocations.
+ */
+static inline struct device *qseecom_scm_dev(struct qseecom_client *client)
+{
+	return client->aux_dev.dev.parent->parent;
+}
+
+/**
+ * qseecom_dma_alloc() - Allocate DMA memory for a QSEECOM client.
+ * @client:     The QSEECOM client to allocate the memory for.
+ * @size:       The number of bytes to allocate.
+ * @dma_handle: Pointer to where the DMA address should be stored.
+ * @gfp:        Allocation flags.
+ *
+ * Wrapper function for dma_alloc_coherent(), allocating DMA memory usable for
+ * TZ/QSEECOM communication. Refer to dma_alloc_coherent() for details.
+ */
+static inline void *qseecom_dma_alloc(struct qseecom_client *client, size_t size,
+				      dma_addr_t *dma_handle, gfp_t gfp)
+{
+	return dma_alloc_coherent(qseecom_scm_dev(client), size, dma_handle, gfp);
+}
+
+/**
+ * dma_free_coherent() - Free QSEECOM DMA memory.
+ * @client:     The QSEECOM client for which the memory has been allocated.
+ * @size:       The number of bytes allocated.
+ * @cpu_addr:   Virtual memory address to free.
+ * @dma_handle: DMA memory address to free.
+ *
+ * Wrapper function for dma_free_coherent(), freeing memory previously
+ * allocated with qseecom_dma_alloc(). Refer to dma_free_coherent() for
+ * details.
+ */
+static inline void qseecom_dma_free(struct qseecom_client *client, size_t size,
+				    void *cpu_addr, dma_addr_t dma_handle)
+{
+	return dma_free_coherent(qseecom_scm_dev(client), size, cpu_addr, dma_handle);
+}
+
+/**
  * qcom_qseecom_app_send() - Send to and receive data from a given QSEE app.
  * @client:   The QSEECOM client associated with the target app.
- * @req:      Request buffer sent to the app (must be DMA-mappable).
+ * @req:      DMA address of the request buffer sent to the app.
  * @req_size: Size of the request buffer.
- * @rsp:      Response buffer, written to by the app (must be DMA-mappable).
+ * @rsp:      DMA address of the response buffer, written to by the app.
  * @rsp_size: Size of the response buffer.
  *
  * Sends a request to the QSEE app associated with the given client and read
@@ -43,8 +89,9 @@ struct qseecom_client {
  *
  * Return: Zero on success, nonzero on failure.
  */
-static inline int qcom_qseecom_app_send(struct qseecom_client *client, void *req, size_t req_size,
-					void *rsp, size_t rsp_size)
+static inline int qcom_qseecom_app_send(struct qseecom_client *client,
+					dma_addr_t req, size_t req_size,
+					dma_addr_t rsp, size_t rsp_size)
 {
 	return qcom_scm_qseecom_app_send(client->app_id, req, req_size, rsp, rsp_size);
 }
diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h
index ccaf28846054..aaa19f93ac43 100644
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -118,8 +118,8 @@ bool qcom_scm_lmh_dcvsh_available(void);
 #ifdef CONFIG_QCOM_QSEECOM
 
 int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id);
-int qcom_scm_qseecom_app_send(u32 app_id, void *req, size_t req_size, void *rsp,
-			      size_t rsp_size);
+int qcom_scm_qseecom_app_send(u32 app_id, dma_addr_t req, size_t req_size,
+			      dma_addr_t rsp, size_t rsp_size);
 
 #else /* CONFIG_QCOM_QSEECOM */
 
@@ -128,9 +128,9 @@ static inline int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id)
 	return -EINVAL;
 }
 
-static inline int qcom_scm_qseecom_app_send(u32 app_id, void *req,
-					    size_t req_size, void *rsp,
-					    size_t rsp_size)
+static inline int qcom_scm_qseecom_app_send(u32 app_id,
+					    dma_addr_t req, size_t req_size,
+					    dma_addr_t rsp, size_t rsp_size)
 {
 	return -EINVAL;
 }