[PATCH] tee: ACPI support for optee driver

From: Mayuresh Chitale
Date: Thu Sep 21 2017 - 03:13:58 EST


This patch modifies the optee driver to add support for parsing
the conduit method from an ACPI node.

Signed-off-by: Mayuresh Chitale <mchitale@xxxxxxx>
---
drivers/tee/optee/core.c | 112 ++++++++++++++++++++++++++++++++---------------
1 file changed, 77 insertions(+), 35 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 58169e5..8b15c49 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -14,6 +14,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

+#include <linux/acpi.h>
#include <linux/arm-smccc.h>
#include <linux/errno.h>
#include <linux/io.h>
@@ -30,6 +31,7 @@
#include "optee_smc.h"

#define DRIVER_NAME "optee"
+#define OPTEE_DEVICE "\\_SB.OPTE"

#define OPTEE_SHM_NUM_PRIV_PAGES 1

@@ -425,29 +427,87 @@ static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
}

-static optee_invoke_fn *get_invoke_func(struct device_node *np)
+static const struct of_device_id optee_match[] = {
+ { .compatible = "linaro,optee-tz" },
+ {},
+};
+
+#ifdef CONFIG_ACPI
+static const char *get_invoke_str_acpi(void)
{
- const char *method;
+ struct acpi_device_info *info;
+ const union acpi_object *obj;
+ struct acpi_device *adev;
+ acpi_status status;
+ acpi_handle handle;

- pr_info("probing for conduit method from DT.\n");
+ status = acpi_get_handle(ACPI_ROOT_OBJECT, OPTEE_DEVICE, &handle);
+ if (ACPI_FAILURE(status))
+ return NULL;

- if (of_property_read_string(np, "method", &method)) {
+ status = acpi_get_object_info(handle, &info);
+ if (ACPI_FAILURE(status) || !(info->valid & ACPI_VALID_HID))
+ return NULL;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return NULL;
+
+ if (acpi_dev_get_property(adev, "method",
+ ACPI_TYPE_ANY, &obj))
+ return NULL;
+
+ return obj->string.pointer;
+}
+#endif
+
+static const char *get_invoke_str_of(void)
+{
+ struct device_node *fw_np;
+ const char *method = NULL;
+ struct device_node *np;
+
+ /* Node is supposed to be below /firmware */
+ fw_np = of_find_node_by_name(NULL, "firmware");
+ if (!fw_np)
+ return NULL;
+
+ np = of_find_matching_node(fw_np, optee_match);
+ of_node_put(fw_np);
+ if (!np)
+ return NULL;
+
+ pr_info("probing for conduit method from DT.\n");
+ if (of_property_read_string(np, "method", &method))
pr_warn("missing \"method\" property\n");
- return ERR_PTR(-ENXIO);
- }

- if (!strcmp("hvc", method))
- return optee_smccc_hvc;
- else if (!strcmp("smc", method))
- return optee_smccc_smc;
+ of_node_put(np);
+ return method;
+}
+
+static optee_invoke_fn *get_invoke_func(void)
+{
+ const char *method;
+
+#ifdef CONFIG_ACPI
+ if (!acpi_disabled)
+ method = get_invoke_str_acpi();
+ else
+#endif
+ method = get_invoke_str_of();
+
+ if (method) {
+ if (!strcmp("hvc", method))
+ return optee_smccc_hvc;
+ else if (!strcmp("smc", method))
+ return optee_smccc_smc;
+ }

pr_warn("invalid \"method\" property: %s\n", method);
return ERR_PTR(-EINVAL);
}

-static struct optee *optee_probe(struct device_node *np)
+static struct optee *optee_probe(optee_invoke_fn *invoke_fn)
{
- optee_invoke_fn *invoke_fn;
struct tee_shm_pool *pool;
struct optee *optee = NULL;
void *memremaped_shm = NULL;
@@ -455,10 +515,6 @@ static struct optee *optee_probe(struct device_node *np)
u32 sec_caps;
int rc;

- invoke_fn = get_invoke_func(np);
- if (IS_ERR(invoke_fn))
- return (void *)invoke_fn;
-
if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
pr_warn("api uid mismatch\n");
return ERR_PTR(-EINVAL);
@@ -570,32 +626,18 @@ static void optee_remove(struct optee *optee)
kfree(optee);
}

-static const struct of_device_id optee_match[] = {
- { .compatible = "linaro,optee-tz" },
- {},
-};
-
static struct optee *optee_svc;

static int __init optee_driver_init(void)
{
- struct device_node *fw_np;
- struct device_node *np;
+ optee_invoke_fn *invoke_fn;
struct optee *optee;

- /* Node is supposed to be below /firmware */
- fw_np = of_find_node_by_name(NULL, "firmware");
- if (!fw_np)
- return -ENODEV;
-
- np = of_find_matching_node(fw_np, optee_match);
- of_node_put(fw_np);
- if (!np)
- return -ENODEV;
-
- optee = optee_probe(np);
- of_node_put(np);
+ invoke_fn = get_invoke_func();
+ if (IS_ERR(invoke_fn))
+ return PTR_ERR(invoke_fn);

+ optee = optee_probe(invoke_fn);
if (IS_ERR(optee))
return PTR_ERR(optee);

--
1.9.1