Re: [PATCH v6 2/2] firmware: arm_scmi: Add qcom smc/hvc transport support
From: Sudeep Holla <hidden>
Date: 2023-10-10 10:43:01
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linux-arm-msm, linux-devicetree, lkml
On Mon, Oct 09, 2023 at 12:14:37PM -0700, Nikunj Kela wrote:
This change adds the support for SCMI message exchange on Qualcomm virtual platforms. The hypervisor associates an object-id also known as capability-id with each smc/hvc doorbell object. The capability-id is used to identify the doorbell from the VM's capability namespace, similar to a file-descriptor. The hypervisor, in addition to the function-id, expects the capability-id to be passed in x1 register when SMC/HVC call is invoked. The capability-id is allocated by the hypervisor on bootup and is stored in the shmem region by the firmware before starting Linux. Signed-off-by: Nikunj Kela <redacted> Reviewed-by: Brian Masney <bmasney@redhat.com> Signed-off-by: Sudeep Holla <redacted>
FYI for the next time. When posting on the list, the senders sign-off must be the last. The only reason I signed off is because it is needed as part of committer in the git repo. You should have ideally dropped it in this case. If there was some other author/co-developer of the patch, then your signoff will be always at the end as you are sending the patch. Refer "Sign your work - the Developer's Certificate of Origin" section in Documentation/process/submitting-patches.rst
quoted hunk ↗ jump to hunk
--- drivers/firmware/arm_scmi/driver.c | 1 + drivers/firmware/arm_scmi/smc.c | 27 +++++++++++++++++++++++++-- 2 files changed, 26 insertions(+), 2 deletions(-)diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 87383c05424b..09371f40d61f 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c@@ -2915,6 +2915,7 @@ static const struct of_device_id scmi_of_match[] = { #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, { .compatible = "arm,scmi-smc-param", .data = &scmi_smc_desc}, + { .compatible = "qcom,scmi-smc", .data = &scmi_smc_desc}, #endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO { .compatible = "arm,scmi-virtio", .data = &scmi_virtio_desc},diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c index 8eba60a41975..7611e9665038 100644 --- a/drivers/firmware/arm_scmi/smc.c +++ b/drivers/firmware/arm_scmi/smc.c@@ -15,6 +15,7 @@ #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> +#include <linux/limits.h> #include <linux/processor.h> #include <linux/slab.h>@@ -50,6 +51,8 @@ * @func_id: smc/hvc call function id * @param_page: 4K page number of the shmem channel * @param_offset: Offset within the 4K page of the shmem channel + * @cap_id: smc/hvc doorbell's capability id to be used on Qualcomm virtual + * platforms */ struct scmi_smc {@@ -63,6 +66,7 @@ struct scmi_smc { unsigned long func_id; unsigned long param_page; unsigned long param_offset; + unsigned long cap_id; }; static irqreturn_t smc_msg_done_isr(int irq, void *data)@@ -124,6 +128,7 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx) { struct device *cdev = cinfo->dev; + unsigned long cap_id = ULONG_MAX; struct scmi_smc *scmi_info; resource_size_t size; struct resource res;@@ -162,6 +167,18 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, if (ret < 0) return ret; + if (of_device_is_compatible(dev->of_node, "qcom,scmi-smc")) { + void __iomem *ptr = (void __iomem *)scmi_info->shmem + size - 8; + /* The capability-id is kept in last 8 bytes of shmem. + * +-------+ <-- 0 + * | shmem | + * +-------+ <-- size - 8 + * | capId | + * +-------+ <-- size + */ + memcpy_fromio(&cap_id, ptr, sizeof(cap_id)); + } + if (of_device_is_compatible(dev->of_node, "arm,scmi-smc-param")) { scmi_info->param_page = SHMEM_PAGE(res.start); scmi_info->param_offset = SHMEM_OFFSET(res.start);@@ -184,6 +201,7 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, } scmi_info->func_id = func_id; + scmi_info->cap_id = cap_id; scmi_info->cinfo = cinfo; smc_channel_lock_init(scmi_info); cinfo->transport_info = scmi_info;@@ -220,8 +238,13 @@ static int smc_send_message(struct scmi_chan_info *cinfo, shmem_tx_prepare(scmi_info->shmem, xfer, cinfo); - arm_smccc_1_1_invoke(scmi_info->func_id, scmi_info->param_page, - scmi_info->param_offset, 0, 0, 0, 0, 0, &res); + if (scmi_info->cap_id != ULONG_MAX) + arm_smccc_1_1_invoke(scmi_info->func_id, scmi_info->cap_id, 0, + 0, 0, 0, 0, 0, &res); + else + arm_smccc_1_1_invoke(scmi_info->func_id, scmi_info->param_page, + scmi_info->param_offset, 0, 0, 0, 0, 0, + &res); /* Only SMCCC_RET_NOT_SUPPORTED is valid error code */ if (res.a0) {-- 2.17.1
-- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel