Re: [PATCH v1 04/16] ufs: core: mcq: Introduce Multi Circular Queue

Manivannan Sadhasivam
2022-09-26T16:02:49Z

On Thu, Sep 22, 2022 at 06:05:11PM -0700, Asutosh Das wrote:
> Introduce multi-circular queue (MCQ) which has been added
> in UFSHC v4.0 standard in addition to the Single Doorbell mode.
> The MCQ mode supports multiple submission and completion queues.
> Add support to configure the number of queues.
>
> Co-developed-by: Can Guo <quic_cang@quicinc.com>
> Signed-off-by: Can Guo <quic_cang@quicinc.com>
> Signed-off-by: Asutosh Das <quic_asutoshd@quicinc.com>
> ---
> drivers/ufs/core/Makefile | 2 +-
> drivers/ufs/core/ufs-mcq.c | 132 +++++++++++++++++++++++++++++++++++++++++
> drivers/ufs/core/ufshcd-priv.h | 1 +
> drivers/ufs/core/ufshcd.c | 12 ++++
> include/ufs/ufshcd.h | 4 ++
> 5 files changed, 150 insertions(+), 1 deletion(-)
> create mode 100644 drivers/ufs/core/ufs-mcq.c
>
> diff --git a/drivers/ufs/core/Makefile b/drivers/ufs/core/Makefile
> index 62f38c5..4d02e0f 100644
> --- a/drivers/ufs/core/Makefile
> +++ b/drivers/ufs/core/Makefile
> @@ -1,7 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
>
> obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
> -ufshcd-core-y += ufshcd.o ufs-sysfs.o
> +ufshcd-core-y += ufshcd.o ufs-sysfs.o ufs-mcq.o
> ufshcd-core-$(CONFIG_DEBUG_FS) += ufs-debugfs.o
> ufshcd-core-$(CONFIG_SCSI_UFS_BSG) += ufs_bsg.o
> ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO) += ufshcd-crypto.o
> diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
> new file mode 100644
> index 0000000..934556f
> --- /dev/null
> +++ b/drivers/ufs/core/ufs-mcq.c
> @@ -0,0 +1,132 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022 Qualcomm Innovation Center. All rights reserved.
> + *
> + * Authors:
> + * Asutosh Das <quic_asutoshd@quicinc.com>
> + * Can Guo <quic_cang@quicinc.com>
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include "ufshcd-priv.h"
> +
> +#define UFS_MCQ_MIN_RW_QUEUES 2
> +#define UFS_MCQ_MIN_READ_QUEUES 0
> +#define UFS_MCQ_MIN_POLL_QUEUES 0
> +
> +static unsigned int dev_cmd_queue = 1;

This looks like a constant, so consider switching to a macro.

> +
> +static int rw_queue_count_set(const char *val, const struct kernel_param *kp)
> +{
> + unsigned int n;
> + int ret;
> +
> + ret = kstrtouint(val, 10, &n);

n is not used? While fixing, please use a better name.

> + if (ret)
> + return ret;

Newline

> + return param_set_uint_minmax(val, kp, UFS_MCQ_MIN_RW_QUEUES,
> + num_possible_cpus());
> +}
> +
> +static const struct kernel_param_ops rw_queue_count_ops = {
> + .set = rw_queue_count_set,
> + .get = param_get_uint,
> +};
> +
> +static unsigned int rw_queues;
> +module_param_cb(rw_queues, &rw_queue_count_ops, &rw_queues, 0644);
> +MODULE_PARM_DESC(rw_queues,
> + "Number of interrupt driven I/O queues used for rw. Default value is nr_cpus");
> +
> +static int read_queue_count_set(const char *val, const struct kernel_param *kp)
> +{
> + unsigned int n;
> + int ret;
> +
> + ret = kstrtouint(val, 10, &n);
> + if (ret)
> + return ret;

Same as above

> + return param_set_uint_minmax(val, kp, UFS_MCQ_MIN_READ_QUEUES,
> + num_possible_cpus());
> +}
> +
> +static const struct kernel_param_ops read_queue_count_ops = {
> + .set = read_queue_count_set,
> + .get = param_get_uint,
> +};
> +
> +static unsigned int read_queues;
> +module_param_cb(read_queues, &read_queue_count_ops, &read_queues, 0644);
> +MODULE_PARM_DESC(read_queues,
> + "Number of interrupt driven read queues used for read. Default value is 0");
> +
> +static int poll_queue_count_set(const char *val, const struct kernel_param *kp)
> +{
> + unsigned int n;
> + int ret;
> +
> + ret = kstrtouint(val, 10, &n);
> + if (ret)
> + return ret;

Same as above

> + return param_set_uint_minmax(val, kp, UFS_MCQ_MIN_POLL_QUEUES,
> + num_possible_cpus());
> +}
> +
> +static const struct kernel_param_ops poll_queue_count_ops = {
> + .set = poll_queue_count_set,
> + .get = param_get_uint,
> +};
> +
> +static unsigned int poll_queues = 1;
> +module_param_cb(poll_queues, &poll_queue_count_ops, &poll_queues, 0644);
> +MODULE_PARM_DESC(poll_queues,
> + "Number of poll queues used for r/w. Default value is 1");
> +
> +static int ufshcd_mcq_config_nr_queues(struct ufs_hba *hba)
> +{
> + int i, rem;
> + u32 hbaq_cap, cmp, tot_queues;
> + struct Scsi_Host *host = hba->host;
> +
> + hbaq_cap = hba->mcq_capabilities & 0xff;

Define 0xff

hbaq_cap should be named after the define used for 0xff. It is not quite
understandable now.

> +
> + if (!rw_queues)
> + rw_queues = num_possible_cpus();
> +
> + tot_queues = dev_cmd_queue + read_queues + poll_queues + rw_queues;
> + if (hbaq_cap < tot_queues) {
> + dev_err(hba->dev, "Total queues (%d) exceeds HC capacity (%d)\n",
> + tot_queues, hbaq_cap);
> + return -EOPNOTSUPP;
> + }
> +
> + rem = hbaq_cap - dev_cmd_queue;
> + cmp = rem;
> + hba->nr_queues[HCTX_TYPE_DEFAULT] = min3(cmp, rw_queues,
> + num_possible_cpus());
> + rem -= hba->nr_queues[HCTX_TYPE_DEFAULT];
> + cmp = rem;
> + hba->nr_queues[HCTX_TYPE_POLL] = min(cmp, poll_queues);

Hmm, so the driver is not using the number of queues set by the user?
If the number varies, I don't think it should be configurable.

Thanks,
Mani

> + rem -= hba->nr_queues[HCTX_TYPE_POLL];
> + cmp = rem;
> + hba->nr_queues[HCTX_TYPE_READ] = min(cmp, read_queues);
> +
> + for (i = 0; i < HCTX_MAX_TYPES; i++)
> + host->nr_hw_queues += hba->nr_queues[i];
> +
> + hba->nr_hw_queues = host->nr_hw_queues + dev_cmd_queue;
> + return 0;
> +}
> +
> +int ufshcd_mcq_init(struct ufs_hba *hba)
> +{
> + int ret;
> +
> + ret = ufshcd_mcq_config_nr_queues(hba);
> +
> + return ret;
> +}
> +
> diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
> index 8f67db2..cf6bdd8e 100644
> --- a/drivers/ufs/core/ufshcd-priv.h
> +++ b/drivers/ufs/core/ufshcd-priv.h
> @@ -50,6 +50,7 @@ int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
> int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
> enum flag_idn idn, u8 index, bool *flag_res);
> void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit);
> +int ufshcd_mcq_init(struct ufs_hba *hba);
>
> #define SD_ASCII_STD true
> #define SD_RAW false
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 426867b..f4bb402 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -8172,6 +8172,15 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
> return ret;
> }
>
> +static int ufshcd_config_mcq(struct ufs_hba *hba)
> +{
> + int ret;
> +
> + ret = ufshcd_mcq_init(hba);
> +
> + return ret;
> +}
> +
> /**
> * ufshcd_probe_hba - probe hba to detect device and initialize it
> * @hba: per-adapter instance
> @@ -8221,6 +8230,9 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool init_dev_params)
> goto out;
>
> if (is_mcq_supported(hba)) {
> + ret = ufshcd_config_mcq(hba);
> + if (ret)
> + goto out;
> ret = scsi_add_host(host, hba->dev);
> if (ret) {
> dev_err(hba->dev, "scsi_add_host failed\n");
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index da7ec0c..298e103 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -827,6 +827,8 @@ struct ufs_hba_monitor {
> * ufshcd_resume_complete()
> * @ext_iid_sup: is EXT_IID is supported by UFSHC
> * @mcq_sup: is mcq supported by UFSHC
> + * @nr_hw_queues: number of hardware queues configured
> + * @nr_queues: number of Queues of different queue types
> */
> struct ufs_hba {
> void __iomem *mmio_base;
> @@ -977,6 +979,8 @@ struct ufs_hba {
> bool complete_put;
> bool ext_iid_sup;
> bool mcq_sup;
> + unsigned int nr_hw_queues;
> + unsigned int nr_queues[HCTX_MAX_TYPES];
> };
>
> static inline bool is_mcq_supported(struct ufs_hba *hba)
> --
> 2.7.4
>

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