[PATCH 2/6] remoteproc: qcom: Add iommu map_unmap helper function

[Mukesh Ojha <quic_mojha@xxxxxxxxxxx>]

From: Komal Bajaj <quic_kbajaj@xxxxxxxxxxx>

Qualcomm remote processor's IOMMU translation running on Linux KVM host
should be managed by PAS driver and to do this PAS driver need to do map
and unmap remoteproc carveout memory region. Similar map and unmap
private functions for the similar purpose are already available in
qcom_q6v5_adsp.c. So, in motivation to reuse code, introduce common
exported functions like qcom_map_unmap_carveout() such that it can be
used by both qcom_q6v5_adsp and qcom_q6v5_pas.

Signed-off-by: Komal Bajaj <quic_kbajaj@xxxxxxxxxxx>
Co-Developed-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
---
 drivers/remoteproc/qcom_common.c | 52 ++++++++++++++++++++++++++++++++
 drivers/remoteproc/qcom_common.h |  3 ++
 2 files changed, 55 insertions(+)

diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
index 8c8688f99f0a..1c7887dc65b4 100644
--- a/drivers/remoteproc/qcom_common.c
+++ b/drivers/remoteproc/qcom_common.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/firmware.h>
+#include <linux/iommu.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
@@ -35,6 +36,8 @@
 #define MINIDUMP_SS_ENCR_DONE		('D' << 24 | 'O' << 16 | 'N' << 8 | 'E' << 0)
 #define MINIDUMP_SS_ENABLED		('E' << 24 | 'N' << 16 | 'B' << 8 | 'L' << 0)
 
+#define SID_MASK_DEFAULT	0xfUL
+
 /**
  * struct minidump_region - Minidump region
  * @name		: Name of the region to be dumped
@@ -606,5 +609,54 @@ void qcom_remove_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm)
 }
 EXPORT_SYMBOL_GPL(qcom_remove_pdm_subdev);
 
+/**
+ * qcom_map_unmap_carveout() - iommu map and unmap carveout region
+ *
+ * @rproc:	rproc handle
+ * @mem_phys:	starting physical address of carveout region
+ * @mem_size:	size of carveout region
+ * @map:	if true, map otherwise, unmap
+ * @use_sid:	decision to append sid to iova
+ * @sid:	SID value
+ */
+int qcom_map_unmap_carveout(struct rproc *rproc, phys_addr_t mem_phys, size_t mem_size,
+			    bool map, bool use_sid, unsigned long sid)
+{
+	unsigned long iova = mem_phys;
+	unsigned long sid_def_val;
+	int ret;
+
+	if (!rproc->has_iommu)
+		return 0;
+
+	if (!rproc->domain)
+		return -EINVAL;
+
+	/*
+	 * Remote processor like ADSP supports upto 36 bit device
+	 * address space and some of its clients like fastrpc uses
+	 * upper 32-35 bits to keep lower 4 bits of its SID to use
+	 * larger address space. To keep this consistent across other
+	 * use cases add remoteproc SID configuration for firmware
+	 * to IOMMU for carveouts.
+	 */
+	if (use_sid && sid) {
+		sid_def_val = sid & SID_MASK_DEFAULT;
+		iova |= (sid_def_val << 32);
+	}
+
+	if (map)
+		ret = iommu_map(rproc->domain, iova, mem_phys, mem_size, IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
+	else
+		ret = iommu_unmap(rproc->domain, iova, mem_size);
+
+	if (ret)
+		dev_err(&rproc->dev, "Unable to %s IOVA Memory, ret: %d\n",
+			map ? "map" : "unmap", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_map_unmap_carveout);
+
 MODULE_DESCRIPTION("Qualcomm Remoteproc helper driver");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/remoteproc/qcom_common.h b/drivers/remoteproc/qcom_common.h
index b07fbaa091a0..bbc41054e1ea 100644
--- a/drivers/remoteproc/qcom_common.h
+++ b/drivers/remoteproc/qcom_common.h
@@ -59,6 +59,9 @@ void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
 			 const char *ssr_name);
 void qcom_remove_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr);
 
+int qcom_map_unmap_carveout(struct rproc *rproc, phys_addr_t mem_phys, size_t mem_size,
+			    bool map, bool use_sid, unsigned long sid);
+
 void qcom_add_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm);
 void qcom_remove_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm);
 
-- 
2.34.1