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Tue, 26 Mar 2019 08:02:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553587371; bh=bPZgnP6vm8+OXqQdN9iVydPzpTvJ4cUhesDJi46cZJk=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=f0Uz1mhFalqnZDiyMTGJW6Hdi9Qu6G2ilJGlRokxsMIGzuaaum21ipKGl5nMmu7Mk dOprlSc/RzdNxJCl7ZMVGSEhf5H4efcJ+4GFHanmyAYtER9x5aZmQJ3O3h1t8Vq5wB ba277nSm6gReJ5iNewCYnWekeRWt9nfexTjmARfg= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 6811160DAA Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=vivek.gautam@codeaurora.org Subject: Re: [PATCH v2 1/4] firmware: qcom_scm-64: Add atomic version of qcom_scm_call To: Bjorn Andersson References: <20180910062551.28175-1-vivek.gautam@codeaurora.org> <20180910062551.28175-2-vivek.gautam@codeaurora.org> <20190325210925.GA2899@builder> From: Vivek Gautam Message-ID: <21b0deec-8663-6b59-52e4-6fe568834eb8@codeaurora.org> Date: Tue, 26 Mar 2019 13:32:46 +0530 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <20190325210925.GA2899@builder> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190326_010253_314025_6343075A X-CRM114-Status: GOOD ( 17.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robdclark@gmail.com, joro@8bytes.org, will.deacon@arm.com, linux-kernel@vger.kernel.org, tfiga@chromium.org, david.brown@linaro.org, iommu@lists.linux-foundation.org, andy.gross@linaro.org, swboyd@chromium.org, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 3/26/2019 2:39 AM, Bjorn Andersson wrote: > On Sun 09 Sep 23:25 PDT 2018, Vivek Gautam wrote: > >> There are scnenarios where drivers are required to make a >> scm call in atomic context, such as in one of the qcom's >> arm-smmu-500 errata [1]. >> >> [1] ("https://source.codeaurora.org/quic/la/kernel/msm-4.9/ >> tree/drivers/iommu/arm-smmu.c?h=msm-4.9#n4842") >> >> Signed-off-by: Vivek Gautam > Reviewed-by: Bjorn Andersson Thanks Bjorn for reviewing and testing this series. I will repost the series on latest head. Best regards Vivek > > Regards, > Bjorn > >> --- >> drivers/firmware/qcom_scm-64.c | 136 ++++++++++++++++++++++++++++------------- >> 1 file changed, 92 insertions(+), 44 deletions(-) >> >> diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c >> index 688525dd4aee..3a8c867cdf51 100644 >> --- a/drivers/firmware/qcom_scm-64.c >> +++ b/drivers/firmware/qcom_scm-64.c >> @@ -70,32 +70,71 @@ static DEFINE_MUTEX(qcom_scm_lock); >> #define FIRST_EXT_ARG_IDX 3 >> #define N_REGISTER_ARGS (MAX_QCOM_SCM_ARGS - N_EXT_QCOM_SCM_ARGS + 1) >> >> -/** >> - * qcom_scm_call() - Invoke a syscall in the secure world >> - * @dev: device >> - * @svc_id: service identifier >> - * @cmd_id: command identifier >> - * @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. >> -*/ >> -static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, >> - const struct qcom_scm_desc *desc, >> - struct arm_smccc_res *res) >> +static void __qcom_scm_call_do(const struct qcom_scm_desc *desc, >> + struct arm_smccc_res *res, u32 fn_id, >> + u64 x5, u32 type) >> +{ >> + u64 cmd; >> + struct arm_smccc_quirk quirk = {.id = ARM_SMCCC_QUIRK_QCOM_A6}; >> + >> + cmd = ARM_SMCCC_CALL_VAL(type, qcom_smccc_convention, >> + ARM_SMCCC_OWNER_SIP, fn_id); >> + >> + quirk.state.a6 = 0; >> + >> + do { >> + arm_smccc_smc_quirk(cmd, desc->arginfo, desc->args[0], >> + desc->args[1], desc->args[2], x5, >> + quirk.state.a6, 0, res, &quirk); >> + >> + if (res->a0 == QCOM_SCM_INTERRUPTED) >> + cmd = res->a0; >> + >> + } while (res->a0 == QCOM_SCM_INTERRUPTED); >> +} >> + >> +static void qcom_scm_call_do(const struct qcom_scm_desc *desc, >> + struct arm_smccc_res *res, u32 fn_id, >> + u64 x5, bool atomic) >> +{ >> + int retry_count = 0; >> + >> + if (!atomic) { >> + do { >> + mutex_lock(&qcom_scm_lock); >> + >> + __qcom_scm_call_do(desc, res, fn_id, x5, >> + ARM_SMCCC_STD_CALL); >> + >> + mutex_unlock(&qcom_scm_lock); >> + >> + if (res->a0 == QCOM_SCM_V2_EBUSY) { >> + if (retry_count++ > QCOM_SCM_EBUSY_MAX_RETRY) >> + break; >> + msleep(QCOM_SCM_EBUSY_WAIT_MS); >> + } >> + } while (res->a0 == QCOM_SCM_V2_EBUSY); >> + } else { >> + __qcom_scm_call_do(desc, res, fn_id, x5, ARM_SMCCC_FAST_CALL); >> + } >> +} >> + >> +static int ___qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, >> + const struct qcom_scm_desc *desc, >> + struct arm_smccc_res *res, bool atomic) >> { >> int arglen = desc->arginfo & 0xf; >> - int retry_count = 0, i; >> + int i; >> u32 fn_id = QCOM_SCM_FNID(svc_id, cmd_id); >> - u64 cmd, x5 = desc->args[FIRST_EXT_ARG_IDX]; >> + u64 x5 = desc->args[FIRST_EXT_ARG_IDX]; >> dma_addr_t args_phys = 0; >> void *args_virt = NULL; >> size_t alloc_len; >> - struct arm_smccc_quirk quirk = {.id = ARM_SMCCC_QUIRK_QCOM_A6}; >> + gfp_t flag = atomic ? GFP_ATOMIC : GFP_KERNEL; >> >> if (unlikely(arglen > N_REGISTER_ARGS)) { >> alloc_len = N_EXT_QCOM_SCM_ARGS * sizeof(u64); >> - args_virt = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL); >> + args_virt = kzalloc(PAGE_ALIGN(alloc_len), flag); >> >> if (!args_virt) >> return -ENOMEM; >> @@ -125,33 +164,7 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, >> x5 = args_phys; >> } >> >> - do { >> - mutex_lock(&qcom_scm_lock); >> - >> - cmd = ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, >> - qcom_smccc_convention, >> - ARM_SMCCC_OWNER_SIP, fn_id); >> - >> - quirk.state.a6 = 0; >> - >> - do { >> - arm_smccc_smc_quirk(cmd, desc->arginfo, desc->args[0], >> - desc->args[1], desc->args[2], x5, >> - quirk.state.a6, 0, res, &quirk); >> - >> - if (res->a0 == QCOM_SCM_INTERRUPTED) >> - cmd = res->a0; >> - >> - } while (res->a0 == QCOM_SCM_INTERRUPTED); >> - >> - mutex_unlock(&qcom_scm_lock); >> - >> - if (res->a0 == QCOM_SCM_V2_EBUSY) { >> - if (retry_count++ > QCOM_SCM_EBUSY_MAX_RETRY) >> - break; >> - msleep(QCOM_SCM_EBUSY_WAIT_MS); >> - } >> - } while (res->a0 == QCOM_SCM_V2_EBUSY); >> + qcom_scm_call_do(desc, res, fn_id, x5, atomic); >> >> if (args_virt) { >> dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE); >> @@ -164,6 +177,41 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, >> return 0; >> } >> >> +/** >> + * qcom_scm_call() - Invoke a syscall in the secure world >> + * @dev: device >> + * @svc_id: service identifier >> + * @cmd_id: command identifier >> + * @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. >> + */ >> +static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, >> + const struct qcom_scm_desc *desc, >> + struct arm_smccc_res *res) >> +{ >> + return ___qcom_scm_call(dev, svc_id, cmd_id, desc, res, false); >> +} >> + >> +/** >> + * qcom_scm_call_atomic() - atomic variation of qcom_scm_call() >> + * @dev: device >> + * @svc_id: service identifier >> + * @cmd_id: command identifier >> + * @desc: Descriptor structure containing arguments and return values >> + * @res: Structure containing results from SMC/HVC call >> + * >> + * Sends a command to the SCM and waits for the command to finish processing. >> + * This should be called in atomic context only. >> + */ >> +static int qcom_scm_call_atomic(struct device *dev, u32 svc_id, u32 cmd_id, >> + const struct qcom_scm_desc *desc, >> + struct arm_smccc_res *res) >> +{ >> + return ___qcom_scm_call(dev, svc_id, cmd_id, desc, res, true); >> +} >> + >> /** >> * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus >> * @entry: Entry point function for the cpus >> -- >> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member >> of Code Aurora Forum, hosted by The Linux Foundation >> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel