> Subject: [PATCH v2 1/5] firmware: arm_scmi: Add discovery of SCMI v2.0
> performance fastchannels
>
> SCMI v2.0 adds support for "FastChannel", a lightweight unidirectional
> channel that is dedicated to a single SCMI message type for controlling a
> specific platform resource. They do not use a message header as they are
> specialized for a single message.
>
> Only PERFORMANCE_LIMITS_{SET,GET} and
> PERFORMANCE_LEVEL_{SET,GET} commands are supported over
> fastchannels. As they are optional, they need to be discovered by
> PERFORMANCE_DESCRIBE_FASTCHANNEL command.
> Further {LIMIT,LEVEL}_SET commands can have optional doorbell support.
>
> Add support for discovery of these fastchannels.
>
> Cc: Ionela Voinescu <ionela.voine...@arm.com>
> Cc: Chris Redpath <chris.redp...@arm.com>
> Cc: Quentin Perret <quentin.per...@arm.com>
> Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com>
> ---
> drivers/firmware/arm_scmi/perf.c | 153
> ++++++++++++++++++++++++++++++-
> 1 file changed, 149 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firmware/arm_scmi/perf.c
> b/drivers/firmware/arm_scmi/perf.c
> index 3c8ae7cc35de..6cce3e82e81e 100644
> --- a/drivers/firmware/arm_scmi/perf.c
> +++ b/drivers/firmware/arm_scmi/perf.c
> @@ -5,7 +5,9 @@
> * Copyright (C) 2018 ARM Ltd.
> */
>
> +#include <linux/bits.h>
> #include <linux/of.h>
> +#include <linux/io.h>
> #include <linux/platform_device.h>
> #include <linux/pm_opp.h>
> #include <linux/sort.h>
> @@ -21,6 +23,7 @@ enum scmi_performance_protocol_cmd {
> PERF_LEVEL_GET = 0x8,
> PERF_NOTIFY_LIMITS = 0x9,
> PERF_NOTIFY_LEVEL = 0xa,
> + PERF_DESCRIBE_FASTCHANNEL = 0xb,
> };
>
> struct scmi_opp {
> @@ -44,6 +47,7 @@ struct scmi_msg_resp_perf_domain_attributes {
> #define SUPPORTS_SET_PERF_LVL(x) ((x) & BIT(30))
> #define SUPPORTS_PERF_LIMIT_NOTIFY(x) ((x) & BIT(29))
> #define SUPPORTS_PERF_LEVEL_NOTIFY(x) ((x) & BIT(28))
> +#define SUPPORTS_PERF_FASTCHANNELS(x) ((x) & BIT(27))
> __le32 rate_limit_us;
> __le32 sustained_freq_khz;
> __le32 sustained_perf_level;
> @@ -87,17 +91,56 @@ struct scmi_msg_resp_perf_describe_levels {
> } opp[0];
> };
>
> +struct scmi_perf_get_fc_info {
> + __le32 domain;
> + __le32 message_id;
> +};
> +
> +struct scmi_msg_resp_perf_desc_fc {
> + __le32 attr;
> +#define SUPPORTS_DOORBELL(x) ((x) & BIT(0))
> +#define DOORBELL_REG_WIDTH(x) FIELD_GET(GENMASK(2, 1), (x))
> + __le32 rate_limit;
> + __le32 chan_addr_low;
> + __le32 chan_addr_high;
> + __le32 chan_size;
> + __le32 db_addr_low;
> + __le32 db_addr_high;
> + __le32 db_set_lmask;
> + __le32 db_set_hmask;
> + __le32 db_preserve_lmask;
> + __le32 db_preserve_hmask;
> +};
> +
> +struct scmi_fc_db_info {
> + int width;
> + u64 set;
> + u64 mask;
> + void __iomem *addr;
> +};
> +
> +struct scmi_fc_info {
> + void __iomem *level_set_addr;
> + void __iomem *limit_set_addr;
> + void __iomem *level_get_addr;
> + void __iomem *limit_get_addr;
> + struct scmi_fc_db_info *level_set_db;
> + struct scmi_fc_db_info *limit_set_db;
> +};
> +
> struct perf_dom_info {
> bool set_limits;
> bool set_perf;
> bool perf_limit_notify;
> bool perf_level_notify;
> + bool perf_fastchannels;
> u32 opp_count;
> u32 sustained_freq_khz;
> u32 sustained_perf_level;
> u32 mult_factor;
> char name[SCMI_MAX_STR_SIZE];
> struct scmi_opp opp[MAX_OPPS];
> + struct scmi_fc_info *fc_info;
> };
>
> struct scmi_perf_info {
> @@ -162,6 +205,7 @@ scmi_perf_domain_attributes_get(const struct
> scmi_handle *handle, u32 domain,
> dom_info->set_perf = SUPPORTS_SET_PERF_LVL(flags);
> dom_info->perf_limit_notify =
> SUPPORTS_PERF_LIMIT_NOTIFY(flags);
> dom_info->perf_level_notify =
> SUPPORTS_PERF_LEVEL_NOTIFY(flags);
> + dom_info->perf_fastchannels =
> SUPPORTS_PERF_FASTCHANNELS(flags);
> dom_info->sustained_freq_khz =
> le32_to_cpu(attr->sustained_freq_khz);
> dom_info->sustained_perf_level =
> @@ -250,7 +294,7 @@ scmi_perf_describe_levels_get(const struct
> scmi_handle *handle, u32 domain, }
>
> static int scmi_perf_limits_set(const struct scmi_handle *handle, u32
> domain,
> - u32 max_perf, u32 min_perf)
> + u32 max_perf, u32 min_perf)
> {
> int ret;
> struct scmi_xfer *t;
> @@ -273,7 +317,7 @@ static int scmi_perf_limits_set(const struct
> scmi_handle *handle, u32 domain, }
>
> static int scmi_perf_limits_get(const struct scmi_handle *handle, u32
> domain,
> - u32 *max_perf, u32 *min_perf)
> + u32 *max_perf, u32 *min_perf)
> {
> int ret;
> struct scmi_xfer *t;
> @@ -299,7 +343,7 @@ static int scmi_perf_limits_get(const struct
> scmi_handle *handle, u32 domain, }
>
> static int scmi_perf_level_set(const struct scmi_handle *handle, u32
> domain,
> - u32 level, bool poll)
> + u32 level, bool poll)
> {
> int ret;
> struct scmi_xfer *t;
> @@ -322,7 +366,7 @@ static int scmi_perf_level_set(const struct
> scmi_handle *handle, u32 domain, }
>
> static int scmi_perf_level_get(const struct scmi_handle *handle, u32
> domain,
> - u32 *level, bool poll)
> + u32 *level, bool poll)
> {
> int ret;
> struct scmi_xfer *t;
> @@ -343,6 +387,104 @@ static int scmi_perf_level_get(const struct
> scmi_handle *handle, u32 domain,
> return ret;
> }
>
> +static bool scmi_perf_fc_size_is_valid(u32 msg, u32 size) {
> + if ((msg == PERF_LEVEL_GET || msg == PERF_LEVEL_SET) && size == 4)
> + return true;
> + if ((msg == PERF_LIMITS_GET || msg == PERF_LIMITS_SET) && size == 8)
> + return true;
> + return false;
> +}
> +
> +static void
> +scmi_perf_domain_desc_fc(const struct scmi_handle *handle, u32 domain,
> + u32 message_id, void __iomem **p_addr,
> + struct scmi_fc_db_info **p_db)
> +{
> + int ret;
> + u32 flags;
> + u64 phys_addr;
> + u8 size;
> + void __iomem *addr;
> + struct scmi_xfer *t;
> + struct scmi_fc_db_info *db;
> + struct scmi_perf_get_fc_info *info;
> + struct scmi_msg_resp_perf_desc_fc *resp;
> +
> + if (!p_addr)
> + return;
> +
> + ret = scmi_xfer_get_init(handle, PERF_DESCRIBE_FASTCHANNEL,
> + SCMI_PROTOCOL_PERF,
> + sizeof(*info), sizeof(*resp), &t);
> + if (ret)
> + return;
> +
> + info = t->tx.buf;
> + info->domain = cpu_to_le32(domain);
> + info->message_id = cpu_to_le32(message_id);
> +
> + ret = scmi_do_xfer(handle, t);
> + if (ret)
> + goto err_xfer;
> +
> + resp = t->rx.buf;
> + flags = le32_to_cpu(resp->attr);
> + size = le32_to_cpu(resp->chan_size);
> + if (!scmi_perf_fc_size_is_valid(message_id, size))
> + goto err_xfer;
> +
> + phys_addr = le32_to_cpu(resp->chan_addr_low);
> + phys_addr |= (u64)le32_to_cpu(resp->chan_addr_high) << 32;
> + addr = devm_ioremap(handle->dev, phys_addr, size);
> + if (!addr)
> + goto err_xfer;
> + *p_addr = addr;
> +
> + if (p_db && SUPPORTS_DOORBELL(flags)) {
> + db = devm_kzalloc(handle->dev, sizeof(*db), GFP_KERNEL);
> + if (!db)
> + goto err_xfer;
> +
> + size = 1 << DOORBELL_REG_WIDTH(flags);
> + phys_addr = le32_to_cpu(resp->db_addr_low);
> + phys_addr |= (u64)le32_to_cpu(resp->db_addr_high) << 32;
> + addr = devm_ioremap(handle->dev, phys_addr, size);
> + if (!addr)
> + goto err_xfer;
> +
> + db->addr = addr;
> + db->width = size;
> + db->set = le32_to_cpu(resp->db_set_lmask);
> + db->set |= (u64)le32_to_cpu(resp->db_set_hmask) << 32;
> + db->mask = le32_to_cpu(resp->db_preserve_lmask);
> + db->mask |= (u64)le32_to_cpu(resp->db_preserve_hmask) << 32;
> + *p_db = db;
> + }
> +err_xfer:
> + scmi_xfer_put(handle, t);
> +}
> +
> +static void scmi_perf_domain_init_fc(const struct scmi_handle *handle,
> + u32 domain, struct scmi_fc_info **p_fc) {
> + struct scmi_fc_info *fc;
> +
> + fc = devm_kzalloc(handle->dev, sizeof(*fc), GFP_KERNEL);
> + if (!fc)
> + return;
> +
> + scmi_perf_domain_desc_fc(handle, domain, PERF_LEVEL_SET,
> + &fc->level_set_addr, &fc->level_set_db);
> + scmi_perf_domain_desc_fc(handle, domain, PERF_LEVEL_GET,
> + &fc->level_get_addr, NULL);
> + scmi_perf_domain_desc_fc(handle, domain, PERF_LIMITS_SET,
> + &fc->limit_set_addr, &fc->limit_set_db);
> + scmi_perf_domain_desc_fc(handle, domain, PERF_LIMITS_GET,
> + &fc->limit_get_addr, NULL);
> + *p_fc = fc;
> +}
> +
> /* Device specific ops */
> static int scmi_dev_domain_id(struct device *dev) { @@ -494,6 +636,9
> @@ static int scmi_perf_protocol_init(struct scmi_handle *handle)
>
> scmi_perf_domain_attributes_get(handle, domain, dom);
> scmi_perf_describe_levels_get(handle, domain, dom);
> +
> + if (dom->perf_fastchannels)
> + scmi_perf_domain_init_fc(handle, domain, &dom->fc_info);
> }
>
> handle->perf_ops = &perf_ops;
Reviewed-by: Peng Fan <peng....@nxp.com>
> --
> 2.17.1
