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Message-ID: <107aad9f-40c0-f32b-9f74-6c82ee6785bf@linaro.org>
Date: Wed, 12 Jul 2023 16:22:51 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
vireshk@...nel.org, nm@...com, sboyd@...nel.org,
myungjoo.ham@...sung.com, kyungmin.park@...sung.com,
cw00.choi@...sung.com, andersson@...nel.org,
konrad.dybcio@...aro.org, robh+dt@...nel.org,
krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org
Cc: linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
quic_asutoshd@...cinc.com, quic_cang@...cinc.com,
quic_nitirawa@...cinc.com, quic_narepall@...cinc.com,
quic_bhaskarv@...cinc.com, quic_richardp@...cinc.com,
quic_nguyenb@...cinc.com, quic_ziqichen@...cinc.com,
bmasney@...hat.com, krzysztof.kozlowski@...aro.org
Subject: Re: [PATCH 14/14] scsi: ufs: qcom: Add support for scaling
interconnects
On 12/07/2023 13:32, Manivannan Sadhasivam wrote:
> Qcom SoCs require scaling the interconnect paths for proper working of the
> peripherals connected through interconnects. Even for accessing the UFS
> controller, someone should setup the interconnect paths. So far, the
> bootloaders used to setup the interconnect paths before booting linux as
> they need to access the UFS storage for things like fetching boot firmware.
> But with the advent of multi boot options, bootloader nowadays like in
> SA8540p SoC do not setup the interconnect paths at all.
>
> So trying to configure UFS in the absence of the interconnect path
> configuration, results in boot crash.
>
> To fix this issue and also to dynamically scale the interconnects (UFS-DDR
> and CPU-UFS), interconnect API support is added to the Qcom UFS driver.
> With this support, the interconnect paths are scaled dynamically based on
> the gear configuration.
>
> During the early stage of ufs_qcom_init(), ufs_qcom_icc_init() will setup
> the paths to max bandwidth to allow configuring the UFS registers. Touching
> the registers without configuring the icc paths would result in a crash.
> However, we don't really need to set max vote for the icc paths as any
> minimal vote would suffice. But the max value would allow initialization to
> be done faster. After init, the bandwidth will get updated using
> ufs_qcom_icc_update_bw() based on the gear and lane configuration.
>
> The bandwidth values defined in ufs_qcom_bw_table struct are taken from
> Qcom downstream vendor devicetree source and are calculated as per the
> UFS3.1 Spec, Section 6.4.1, HS Gear Rates. So it is fixed across platforms.
>
> Cc: Brian Masney <bmasney@...hat.com>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
> ---
> drivers/ufs/host/ufs-qcom.c | 131 +++++++++++++++++++++++++++++++++++-
> drivers/ufs/host/ufs-qcom.h | 3 +
> 2 files changed, 133 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> index 8d6fd4c3324f..8a3132d45a65 100644
> --- a/drivers/ufs/host/ufs-qcom.c
> +++ b/drivers/ufs/host/ufs-qcom.c
> @@ -7,6 +7,7 @@
> #include <linux/time.h>
> #include <linux/clk.h>
> #include <linux/delay.h>
> +#include <linux/interconnect.h>
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/platform_device.h>
> @@ -46,6 +47,49 @@ enum {
> TSTBUS_MAX,
> };
>
> +#define QCOM_UFS_MAX_GEAR 4
> +#define QCOM_UFS_MAX_LANE 2
> +
> +enum {
> + MODE_MIN,
> + MODE_PWM,
> + MODE_HS_RA,
> + MODE_HS_RB,
> + MODE_MAX,
MODE_MIN and MODE_MAX seem to be unused
> +};
> +
> +struct __ufs_qcom_bw_table {
> + u32 bw1;
> + u32 bw2;
Please consider:
s/bw1/mem_bw/
s/bw2/cfg_bw/
> +} ufs_qcom_bw_table[MODE_MAX + 1][QCOM_UFS_MAX_GEAR + 1][QCOM_UFS_MAX_LANE + 1] = {
I'd say, these +1's are slightly confusing and unnecessary.
> + [MODE_MIN][0][0] = { 0, 0 }, /* Bandwidth values are in KB/s */
I'd say, this becomes impossible to check. Can you please structure it?
Either by inclusion:
[MODE_PWM] = {
[1] = {
[1] = { .. },
[2] = { .. },
},
// etc.
};
Also, do we have defines for gears? Can we use them instead of indices?
> + [MODE_PWM][1][1] = { 922, 1000 },
> + [MODE_PWM][2][1] = { 1844, 1000 },
> + [MODE_PWM][3][1] = { 3688, 1000 },
> + [MODE_PWM][4][1] = { 7376, 1000 },
> + [MODE_PWM][1][2] = { 1844, 1000 },
> + [MODE_PWM][2][2] = { 3688, 1000 },
> + [MODE_PWM][3][2] = { 7376, 1000 },
> + [MODE_PWM][4][2] = { 14752, 1000 },
> + [MODE_HS_RA][1][1] = { 127796, 1000 },
> + [MODE_HS_RA][2][1] = { 255591, 1000 },
> + [MODE_HS_RA][3][1] = { 1492582, 102400 },
> + [MODE_HS_RA][4][1] = { 2915200, 204800 },
> + [MODE_HS_RA][1][2] = { 255591, 1000 },
> + [MODE_HS_RA][2][2] = { 511181, 1000 },
> + [MODE_HS_RA][3][2] = { 1492582, 204800 },
> + [MODE_HS_RA][4][2] = { 2915200, 409600 },
> + [MODE_HS_RB][1][1] = { 149422, 1000 },
> + [MODE_HS_RB][2][1] = { 298189, 1000 },
> + [MODE_HS_RB][3][1] = { 1492582, 102400 },
> + [MODE_HS_RB][4][1] = { 2915200, 204800 },
> + [MODE_HS_RB][1][2] = { 298189, 1000 },
> + [MODE_HS_RB][2][2] = { 596378, 1000 },
> + [MODE_HS_RB][3][2] = { 1492582, 204800 },
> + [MODE_HS_RB][4][2] = { 2915200, 409600 },
> + [MODE_MAX][0][0] = { 7643136, 307200 },
> +};
> +
> static struct ufs_qcom_host *ufs_qcom_hosts[MAX_UFS_QCOM_HOSTS];
>
> static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
> @@ -789,6 +833,51 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
> }
> }
>
> +static int ufs_qcom_icc_set_bw(struct ufs_qcom_host *host, u32 bw1, u32 bw2)
> +{
> + struct device *dev = host->hba->dev;
> + int ret;
> +
> + ret = icc_set_bw(host->icc_ddr, 0, bw1);
> + if (ret < 0) {
> + dev_err(dev, "failed to set bandwidth request: %d\n", ret);
> + return ret;
> + }
> +
> + ret = icc_set_bw(host->icc_cpu, 0, bw2);
> + if (ret < 0) {
> + dev_err(dev, "failed to set bandwidth request: %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static struct __ufs_qcom_bw_table ufs_qcom_get_bw_table(struct ufs_qcom_host *host)
> +{
> + struct ufs_pa_layer_attr *p = &host->dev_req_params;
> + int gear = max_t(u32, p->gear_rx, p->gear_tx);
> + int lane = max_t(u32, p->lane_rx, p->lane_tx);
> +
> + if (ufshcd_is_hs_mode(p)) {
> + if (p->hs_rate == PA_HS_MODE_B)
> + return ufs_qcom_bw_table[MODE_HS_RB][gear][lane];
> + else
> + return ufs_qcom_bw_table[MODE_HS_RA][gear][lane];
> + } else {
> + return ufs_qcom_bw_table[MODE_PWM][gear][lane];
> + }
> +}
> +
> +static int ufs_qcom_icc_update_bw(struct ufs_qcom_host *host)
> +{
> + struct __ufs_qcom_bw_table bw_table;
> +
> + bw_table = ufs_qcom_get_bw_table(host);
> +
> + return ufs_qcom_icc_set_bw(host, bw_table.bw1, bw_table.bw2);
> +}
> +
> static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
> enum ufs_notify_change_status status,
> struct ufs_pa_layer_attr *dev_max_params,
> @@ -852,6 +941,8 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
> memcpy(&host->dev_req_params,
> dev_req_params, sizeof(*dev_req_params));
>
> + ufs_qcom_icc_update_bw(host);
> +
> /* disable the device ref clock if entered PWM mode */
> if (ufshcd_is_hs_mode(&hba->pwr_info) &&
> !ufshcd_is_hs_mode(dev_req_params))
> @@ -981,7 +1072,9 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
>
> switch (status) {
> case PRE_CHANGE:
> - if (!on) {
> + if (on) {
> + ufs_qcom_icc_update_bw(host);
> + } else {
> if (!ufs_qcom_is_link_active(hba)) {
> /* disable device ref_clk */
> ufs_qcom_dev_ref_clk_ctrl(host, false);
> @@ -993,6 +1086,9 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
> /* enable the device ref clock for HS mode*/
> if (ufshcd_is_hs_mode(&hba->pwr_info))
> ufs_qcom_dev_ref_clk_ctrl(host, true);
> + } else {
> + ufs_qcom_icc_set_bw(host, ufs_qcom_bw_table[MODE_MIN][0][0].bw1,
> + ufs_qcom_bw_table[MODE_MIN][0][0].bw2);
> }
> break;
> }
> @@ -1031,6 +1127,34 @@ static const struct reset_control_ops ufs_qcom_reset_ops = {
> .deassert = ufs_qcom_reset_deassert,
> };
>
> +static int ufs_qcom_icc_init(struct ufs_qcom_host *host)
> +{
> + struct device *dev = host->hba->dev;
> + int ret;
> +
> + host->icc_ddr = devm_of_icc_get(dev, "ufs-ddr");
> + if (IS_ERR(host->icc_ddr))
> + return dev_err_probe(dev, PTR_ERR(host->icc_ddr),
> + "failed to acquire interconnect path\n");
> +
> + host->icc_cpu = devm_of_icc_get(dev, "cpu-ufs");
> + if (IS_ERR(host->icc_cpu))
> + return dev_err_probe(dev, PTR_ERR(host->icc_cpu),
> + "failed to acquire interconnect path\n");
> +
> + /*
> + * Set Maximum bandwidth vote before initializing the UFS controller and
> + * device. Ideally, a minimal interconnect vote would suffice for the
> + * initialization, but a max vote would allow faster initialization.
> + */
> + ret = ufs_qcom_icc_set_bw(host, ufs_qcom_bw_table[MODE_MAX][0][0].bw1,
> + ufs_qcom_bw_table[MODE_MAX][0][0].bw2);
> + if (ret < 0)
> + return dev_err_probe(dev, ret, "failed to set bandwidth request\n");
> +
> + return 0;
> +}
> +
> /**
> * ufs_qcom_init - bind phy with controller
> * @hba: host controller instance
> @@ -1085,6 +1209,10 @@ static int ufs_qcom_init(struct ufs_hba *hba)
> }
> }
>
> + err = ufs_qcom_icc_init(host);
> + if (err)
> + goto out_variant_clear;
> +
> host->device_reset = devm_gpiod_get_optional(dev, "reset",
> GPIOD_OUT_HIGH);
> if (IS_ERR(host->device_reset)) {
> @@ -1282,6 +1410,7 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
> dev_req_params->pwr_rx,
> dev_req_params->hs_rate,
> false);
> + ufs_qcom_icc_update_bw(host);
> ufshcd_uic_hibern8_exit(hba);
> }
>
> diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
> index 6289ad5a42d0..dc27395ecba1 100644
> --- a/drivers/ufs/host/ufs-qcom.h
> +++ b/drivers/ufs/host/ufs-qcom.h
> @@ -206,6 +206,9 @@ struct ufs_qcom_host {
> struct clk *tx_l1_sync_clk;
> bool is_lane_clks_enabled;
>
> + struct icc_path *icc_ddr;
> + struct icc_path *icc_cpu;
> +
> #ifdef CONFIG_SCSI_UFS_CRYPTO
> struct qcom_ice *ice;
> #endif
--
With best wishes
Dmitry
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