Merge "soc: qcom: scm: Add a noretry variant for scm_call2" into msm-4.14 (7602e342) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/soc/qcom/scm.c

+44 −25

Original line number	Diff line number	Diff line
		/* Copyright (c) 2010-2017, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2010-2018, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -357,28 +357,7 @@ static int allocate_extra_arg_buffer(struct scm_desc *desc, gfp_t flags)
		return 0;
		}

		/**
		* scm_call2() - Invoke a syscall in the secure world
		* @fn_id: The function ID for this syscall
		* @desc: Descriptor structure containing arguments and return values
		*
		* Sends a command to the SCM and waits for the command to finish processing.
		* This should only be called in pre-emptible context.
		*
		* A note on cache maintenance:
		* Note that any buffers that are expected to be accessed by the secure world
		* must be flushed before invoking scm_call and invalidated in the cache
		* immediately after scm_call returns. An important point that must be noted
		* is that on ARMV8 architectures, invalidation actually also causes a dirty
		* cache line to be cleaned (flushed + unset-dirty-bit). Therefore it is of
		* paramount importance that the buffer be flushed before invoking scm_call2,
		* even if you don't care about the contents of that buffer.
		*
		* Note that cache maintenance on the argument buffer (desc->args) is taken care
		* of by scm_call2; however, callers are responsible for any other cached
		* buffers passed over to the secure world.
		*/
		int scm_call2(u32 fn_id, struct scm_desc *desc)
		static int __scm_call2(u32 fn_id, struct scm_desc *desc, bool retry)
		{
		int arglen = desc->arginfo & 0xf;
		int ret, retry_count = 0;
		@@ -419,13 +398,15 @@ int scm_call2(u32 fn_id, struct scm_desc *desc)
		mutex_unlock(&scm_lmh_lock);

		mutex_unlock(&scm_lock);
		if (!retry)
		goto out;

		if (ret == SCM_V2_EBUSY)
		msleep(SCM_EBUSY_WAIT_MS);
		if (retry_count == 33)
		pr_warn("scm: secure world has been busy for 1 second!\n");
		} while (ret == SCM_V2_EBUSY && (retry_count++ < SCM_EBUSY_MAX_RETRY));

		out:
		trace_scm_call_end(desc);
		if (ret < 0)
		pr_err("scm_call failed: func id %#llx, ret: %d, syscall returns: %#llx, %#llx, %#llx\n",
		@@ -437,8 +418,46 @@ int scm_call2(u32 fn_id, struct scm_desc *desc)
		return scm_remap_error(ret);
		return 0;
		}

		/**
		* scm_call2() - Invoke a syscall in the secure world
		* @fn_id: The function ID for this syscall
		* @desc: Descriptor structure containing arguments and return values
		*
		* Sends a command to the SCM and waits for the command to finish processing.
		* This should only be called in pre-emptible context.
		*
		* A note on cache maintenance:
		* Note that any buffers that are expected to be accessed by the secure world
		* must be flushed before invoking scm_call and invalidated in the cache
		* immediately after scm_call returns. An important point that must be noted
		* is that on ARMV8 architectures, invalidation actually also causes a dirty
		* cache line to be cleaned (flushed + unset-dirty-bit). Therefore it is of
		* paramount importance that the buffer be flushed before invoking scm_call2,
		* even if you don't care about the contents of that buffer.
		*
		* Note that cache maintenance on the argument buffer (desc->args) is taken care
		* of by scm_call2; however, callers are responsible for any other cached
		* buffers passed over to the secure world.
		*/
		int scm_call2(u32 fn_id, struct scm_desc *desc)
		{
		return __scm_call2(fn_id, desc, true);
		}
		EXPORT_SYMBOL(scm_call2);

		/**
		* scm_call2_noretry() - Invoke a syscall in the secure world
		*
		* Similar to scm_call2 except that there is no retry mechanism
		* implemented.
		*/
		int scm_call2_noretry(u32 fn_id, struct scm_desc *desc)
		{
		return __scm_call2(fn_id, desc, false);
		}
		EXPORT_SYMBOL(scm_call2_noretry);

		/**
		* scm_call2_atomic() - Invoke a syscall in the secure world
		*

include/soc/qcom/scm.h

+7 −1

Original line number	Diff line number	Diff line
		/* Copyright (c) 2010-2017, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2010-2018, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -98,6 +98,7 @@ struct scm_desc {

		#define SCM_VERSION(major, minor) (((major) << 16) \| ((minor) & 0xFF))
		extern int scm_call2(u32 cmd_id, struct scm_desc *desc);
		extern int scm_call2_noretry(u32 cmd_id, struct scm_desc *desc);
		extern int scm_call2_atomic(u32 cmd_id, struct scm_desc *desc);
		extern u32 scm_get_version(void);
		extern int scm_is_call_available(u32 svc_id, u32 cmd_id);
		@@ -114,6 +115,11 @@ static inline int scm_call2(u32 cmd_id, struct scm_desc *desc)
		return 0;
		}

		static inline int scm_call2_noretry(u32 cmd_id, struct scm_desc *desc)
		{
		return 0;
		}

		static inline int scm_call2_atomic(u32 cmd_id, struct scm_desc *desc)
		{
		return 0;