From: eberman@codeaurora.org
To: Stephen Boyd <swboyd@chromium.org>
Cc: agross@kernel.org, bjorn.andersson@linaro.org,
saiprakash.ranjan@codeaurora.org, tsoni@codeaurora.org,
sidgup@codeaurora.org, psodagud@codeaurora.org,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 10/18] firmware: qcom_scm-64: Improve SMC convention detection
Date: Fri, 15 Nov 2019 17:29:03 -0800 [thread overview]
Message-ID: <9b17a38238447780199a7902d8ca0943@codeaurora.org> (raw)
In-Reply-To: <5dcf4109.1c69fb81.ef683.dbd7@mx.google.com>
On 2019-11-15 16:21, Stephen Boyd wrote:
> Quoting Elliot Berman (2019-11-12 13:22:46)
>> diff --git a/drivers/firmware/qcom_scm-64.c
>> b/drivers/firmware/qcom_scm-64.c
>> index 977654bb..b82b450 100644
>> --- a/drivers/firmware/qcom_scm-64.c
>> +++ b/drivers/firmware/qcom_scm-64.c
>> @@ -302,21 +302,20 @@ int __qcom_scm_hdcp_req(struct device *dev,
>> struct qcom_scm_hdcp_req *req,
>>
>> void __qcom_scm_init(void)
>> {
>> - u64 cmd;
>> - struct arm_smccc_res res;
>> - u32 function = SMCCC_FUNCNUM(QCOM_SCM_SVC_INFO,
>> QCOM_SCM_INFO_IS_CALL_AVAIL);
>> -
>> - /* First try a SMC64 call */
>> - cmd = ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,
>> ARM_SMCCC_SMC_64,
>> - ARM_SMCCC_OWNER_SIP, function);
>> -
>> - arm_smccc_smc(cmd, QCOM_SCM_ARGS(1), cmd &
>> (~BIT(ARM_SMCCC_TYPE_SHIFT)),
>> - 0, 0, 0, 0, 0, &res);
>> -
>> - if (!res.a0 && res.a1)
>> - qcom_smccc_convention = ARM_SMCCC_SMC_64;
>> - else
>> - qcom_smccc_convention = ARM_SMCCC_SMC_32;
>> + qcom_smccc_convention = ARM_SMCCC_SMC_64;
>> + if (__qcom_scm_is_call_available(NULL, QCOM_SCM_SVC_INFO,
>> + QCOM_SCM_INFO_IS_CALL_AVAIL) == 1)
>
> Is this asking if the "is call available function" is available by
> using
> the is call available function? That is recursive. Isn't that why we
> make a manually open coded SMC call to see if it works? If this isn't
> going to work we may want to just have a property in DT that tells us
> what to do.
Yes. The reason the open coded SMC call was made was because a fast call
works better here. __qcom_scm_is_call_available uses standard call, and
I'll address this in v3.
>> + BUG();
>
> This BUG() is new and not mentioned in the commit text. Why can't we
> just start failing all scm calls if we can't detect the calling
> convention?
Bjorn has requested that the BUG was introduced in v1:
https://lore.kernel.org/patchwork/patch/1148619/#1350062
>> +out:
>> + pr_debug("QCOM SCM SMC Convention: %llu\n",
>> qcom_smccc_convention);
>
> Maybe pr_info() is more appropriate. PSCI currently prints out the
> version info so maybe printing something like "QCOM SCM SMC_64 calling
> convention" will be useful for early debugging.
Sure, will do.
Thanks,
Elliot
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2019-11-16 1:29 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 21:22 [PATCH v2 00/18] Restructure, improve target support for qcom_scm driver Elliot Berman
2019-11-12 21:22 ` [PATCH v2 01/18] firmware: qcom_scm: Rename macros and structures Elliot Berman
2019-11-15 23:27 ` Stephen Boyd
2019-11-16 1:19 ` eberman
2019-11-19 21:47 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 02/18] firmware: qcom_scm: Add funcnum IDs Elliot Berman
2019-11-15 23:30 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 03/18] firmware: qcom_scm-64: Make SMCCC macros less magical Elliot Berman
2019-11-15 22:43 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 04/18] firmware: qcom_scm: Apply consistent naming scheme to command IDs Elliot Berman
2019-11-15 22:45 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 05/18] firmware: qcom_scm: Remove unused qcom_scm_get_version Elliot Berman
2019-11-15 22:45 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 06/18] firmware: qcom_scm-64: Move svc/cmd/owner into qcom_scm_desc Elliot Berman
2019-11-15 23:40 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 07/18] firmware: qcom_scm-64: Add SCM results to descriptor Elliot Berman
2019-11-15 23:42 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 08/18] firmware: qcom_scm-64: Remove qcom_scm_call_do_smccc Elliot Berman
2019-11-15 23:45 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 09/18] firmware: qcom_scm-64: Move SMC register filling to qcom_scm_call_smccc Elliot Berman
2019-11-15 23:57 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 10/18] firmware: qcom_scm-64: Improve SMC convention detection Elliot Berman
2019-11-16 0:21 ` Stephen Boyd
2019-11-16 1:29 ` eberman [this message]
2019-11-19 21:49 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 11/18] firmware: qcom_scm-32: Use SMC arch wrappers Elliot Berman
2019-11-16 0:41 ` Stephen Boyd
2019-12-12 19:45 ` Elliot Berman
2019-11-12 21:22 ` [PATCH v2 12/18] firmware: qcom_scm-32: Use qcom_scm_desc in non-atomic calls Elliot Berman
2019-11-19 22:03 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 13/18] firmware: qcom_scm-32: Move SMCCC register filling to qcom_scm_call Elliot Berman
2019-11-19 22:05 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 14/18] firmware: qcom_scm-32: Create common legacy atomic call Elliot Berman
2019-11-19 22:11 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 15/18] firmware: qcom_scm-32: Add device argument to atomic calls Elliot Berman
2019-11-19 22:13 ` Stephen Boyd
2019-11-12 21:22 ` [PATCH v2 16/18] firmware: qcom_scm: Remove thin wrappers Elliot Berman
2019-11-12 21:22 ` [PATCH v2 17/18] firmware: qcom_scm: Dynamically support SMCCC and legacy conventions Elliot Berman
2019-11-12 21:22 ` [PATCH v2 18/18] firmware: qcom_scm: Order functions, definitions by service/command Elliot Berman
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