linux-kernel - [PATCH v5 04/17] firmware: qcom_scm-64: Make SMC macros less magical

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Message-Id: <1578431066-19600-5-git-send-email-eberman@codeaurora.org>
Date:   Tue,  7 Jan 2020 13:04:13 -0800
From:   Elliot Berman <eberman@...eaurora.org>
To:     Bjorn Andersson <bjorn.andersson@...aro.org>, agross@...nel.org,
        swboyd@...omium.org, Stephan Gerhold <stephan@...hold.net>
Cc:     Elliot Berman <eberman@...eaurora.org>,
        saiprakash.ranjan@...eaurora.org, tsoni@...eaurora.org,
        sidgup@...eaurora.org, psodagud@...eaurora.org,
        Brian Masney <masneyb@...tation.org>,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v5 04/17] firmware: qcom_scm-64: Make SMC macros less magical

Improve understandability of SMC macros by reversing the logic as they
are all functions of how many arguments can be shoved in registers and
how many SCM arguments are supported.

There aren't 4 register arguments because are 7 arguments that go into a
buffer - there are up to 7 arguments that are overflowed into a buffer
because only 4 registers are allocated for arguments.

Change-Id: Iac0378fc4c5e20943a64b98223d53caa4955dd53
Reviewed-by: Stephen Boyd <swboyd@...omium.org>
Tested-by: Brian Masney <masneyb@...tation.org> # arm32
Tested-by: Stephan Gerhold <stephan@...hold.net>
Signed-off-by: Elliot Berman <eberman@...eaurora.org>
---
 drivers/firmware/qcom_scm-64.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index 976c2b9..3101f36 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -58,9 +58,9 @@ static DEFINE_MUTEX(qcom_scm_lock);
 #define QCOM_SCM_EBUSY_WAIT_MS 30
 #define QCOM_SCM_EBUSY_MAX_RETRY 20
 
-#define SCM_SMC_N_EXT_ARGS 7
-#define SCM_SMC_FIRST_EXT_IDX 3
-#define SCM_SMC_N_REG_ARGS (MAX_QCOM_SCM_ARGS - SCM_SMC_N_EXT_ARGS + 1)
+#define SCM_SMC_N_REG_ARGS	4
+#define SCM_SMC_FIRST_EXT_IDX	(SCM_SMC_N_REG_ARGS - 1)
+#define SCM_SMC_N_EXT_ARGS	(MAX_QCOM_SCM_ARGS - SCM_SMC_N_REG_ARGS + 1)
 
 static void __scm_smc_do_quirk(const struct qcom_scm_desc *desc,
 			       struct arm_smccc_res *res, u32 fn_id,
-- 
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