[Intel-gfx] [PATCH 2/5] drm/i915/skl+: Decode memory bandwidth and parameters
Rodrigo Vivi
rodrigo.vivi at intel.com
Thu Aug 16 22:35:49 UTC 2018
On Thu, Jul 26, 2018 at 07:44:07PM +0530, Mahesh Kumar wrote:
> This patch adds support to decode system memory bandwidth and other
> parameters for skylake and Gen9+ platforms, which will be used for
> arbitrated display memory bandwidth calculation in GEN9 based
> platforms and WM latency level-0 Work-around calculation on GEN9+.
>
> Changes Since V1:
> - s/memdev_info/dram_info
> - create a struct to hold channel info
>
> Signed-off-by: Mahesh Kumar <mahesh1.kumar at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 131 ++++++++++++++++++++++++++++++++++++++--
> drivers/gpu/drm/i915/i915_drv.h | 7 +++
> drivers/gpu/drm/i915/i915_reg.h | 21 +++++++
> 3 files changed, 155 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 16629601c9f4..ddf6bf9b500a 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1070,6 +1070,118 @@ static void intel_sanitize_options(struct drm_i915_private *dev_priv)
> intel_gvt_sanitize_options(dev_priv);
> }
>
> +static int
> +skl_dram_get_channel_info(struct dram_channel_info *ch, u32 val)
> +{
> + u8 l_rank, s_rank;
> + u8 l_size, s_size;
> + u8 l_width, s_width;
> + enum dram_rank rank;
> +
> + if (!val)
> + return -1;
-SOMEERRNO?
> +
> + l_size = (val >> SKL_DRAM_SIZE_L_SHIFT) & SKL_DRAM_SIZE_MASK;
> + s_size = (val >> SKL_DRAM_SIZE_S_SHIFT) & SKL_DRAM_SIZE_MASK;
> + l_width = (val >> SKL_DRAM_WIDTH_L_SHIFT) & SKL_DRAM_WIDTH_MASK;
> + s_width = (val >> SKL_DRAM_WIDTH_S_SHIFT) & SKL_DRAM_WIDTH_MASK;
> + l_rank = (val >> SKL_DRAM_RANK_L_SHIFT) & SKL_DRAM_RANK_MASK;
> + s_rank = (val >> SKL_DRAM_RANK_S_SHIFT) & SKL_DRAM_RANK_MASK;
> +
> + if (l_size == 0 && s_size == 0)
> + return -1;
ditto
> +
> + DRM_DEBUG_KMS("(size:width:rank) L(%dGB:X%d:%s) S(%dGB:X%d:%s)\n",
> + l_size, (1 << l_width) * 8, l_rank ? "dual" : "single",
> + s_size, (1 << s_width) * 8, s_rank ? "dual" : "single");
> +
> + if (l_rank == SKL_DRAM_RANK_DUAL || s_rank == SKL_DRAM_RANK_DUAL)
> + rank = I915_DRAM_RANK_DUAL;
> + else if ((l_size && l_rank == SKL_DRAM_RANK_SINGLE) &&
> + (s_size && s_rank == SKL_DRAM_RANK_SINGLE))
> + rank = I915_DRAM_RANK_DUAL;
> + else
> + rank = I915_DRAM_RANK_SINGLE;
> +
> + ch->l_info.size = l_size;
> + ch->s_info.size = s_size;
> + ch->l_info.width = l_width;
> + ch->s_info.width = s_width;
> + ch->l_info.rank = l_rank;
> + ch->s_info.rank = s_rank;
> + ch->rank = rank;
could we do this directly without intermediates? not clear if we change
in the middle after printing...
> +
> + return 0;
> +}
> +
> +static int
> +skl_dram_get_channels_info(struct drm_i915_private *dev_priv)
> +{
> + struct dram_info *dram_info = &dev_priv->dram_info;
> + struct dram_channel_info ch0, ch1;
> + u32 val;
> + int ret;
> +
> + val = I915_READ(SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN);
> + ret = skl_dram_get_channel_info(&ch0, val);
> + if (ret == 0)
> + dram_info->num_channels++;
> +
> + val = I915_READ(SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN);
> + ret = skl_dram_get_channel_info(&ch1, val);
> + if (ret == 0)
> + dram_info->num_channels++;
> +
> + if (dram_info->num_channels == 0) {
> + DRM_INFO("Number of memory channels is zero\n");
> + return -EINVAL;
> + }
> +
> + /*
> + * If any of the channel is single rank channel, worst case output
> + * will be same as if single rank memory, so consider single rank
> + * memory.
> + */
> + if (ch0.rank == I915_DRAM_RANK_SINGLE ||
> + ch1.rank == I915_DRAM_RANK_SINGLE)
> + dram_info->rank = I915_DRAM_RANK_SINGLE;
> + else
> + dram_info->rank = max(ch0.rank, ch1.rank);
> +
> + if (dram_info->rank == I915_DRAM_RANK_INVALID) {
> + DRM_INFO("couldn't get memory rank information\n");
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int
> +skl_get_dram_info(struct drm_i915_private *dev_priv)
> +{
> + struct dram_info *dram_info = &dev_priv->dram_info;
> + u32 mem_freq_khz, val;
> + int ret;
> +
> + ret = skl_dram_get_channels_info(dev_priv);
> + if (ret)
> + return ret;
> +
> + val = I915_READ(SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU);
> + mem_freq_khz = DIV_ROUND_UP((val & SKL_REQ_DATA_MASK) *
> + SKL_MEMORY_FREQ_MULTIPLIER_HZ, 1000);
> +
> + dram_info->bandwidth_kbps = dram_info->num_channels *
> + mem_freq_khz * 8;
> +
> + if (dram_info->bandwidth_kbps == 0) {
> + DRM_INFO("Couldn't get system memory bandwidth\n");
> + return -EINVAL;
> + }
> +
> + dram_info->valid = true;
> + return 0;
> +}
> +
> static int
> bxt_get_dram_info(struct drm_i915_private *dev_priv)
> {
> @@ -1159,6 +1271,7 @@ static void
> intel_get_dram_info(struct drm_i915_private *dev_priv)
> {
> struct dram_info *dram_info = &dev_priv->dram_info;
> + char bandwidth_str[32];
> int ret;
>
> dram_info->valid = false;
> @@ -1166,15 +1279,25 @@ intel_get_dram_info(struct drm_i915_private *dev_priv)
> dram_info->bandwidth_kbps = 0;
> dram_info->num_channels = 0;
>
> - if (!IS_BROXTON(dev_priv))
> + if (INTEL_GEN(dev_priv) < 9)
> return;
>
> - ret = bxt_get_dram_info(dev_priv);
> + /* Need to calculate bandwidth only for Gen9 */
> + if (IS_BROXTON(dev_priv))
> + ret = bxt_get_dram_info(dev_priv);
> + else if (INTEL_GEN(dev_priv) == 9)
> + ret = skl_get_dram_info(dev_priv);
> + else
> + ret = skl_dram_get_channels_info(dev_priv);
I din't get this... why newer platforms only need this partial path?
also this highlights that the names of the functions are confusing...
> if (ret)
> return;
>
> - DRM_DEBUG_KMS("DRAM bandwidth:%d KBps, total-channels: %u\n",
> - dram_info->bandwidth_kbps, dram_info->num_channels);
> + if (dram_info->bandwidth_kbps)
> + sprintf(bandwidth_str, "%d KBps", dram_info->bandwidth_kbps);
> + else
> + sprintf(bandwidth_str, "unknown");
> + DRM_DEBUG_KMS("DRAM bandwidth:%s, total-channels: %u\n",
> + bandwidth_str, dram_info->num_channels);
> DRM_DEBUG_KMS("DRAM rank: %s rank\n",
> (dram_info->rank == I915_DRAM_RANK_DUAL) ?
> "dual" : "single");
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 46f942fa7d60..2d12fc152b49 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2128,6 +2128,13 @@ struct drm_i915_private {
> */
> };
>
> +struct dram_channel_info {
> + struct info {
> + u8 size, width, rank;
> + } l_info, s_info;
> + enum dram_rank rank;
why do we need duplicated rand information?
> +};
> +
> static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
> {
> return container_of(dev, struct drm_i915_private, drm);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 66900d027570..e4d61167fb64 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9664,6 +9664,27 @@ enum skl_power_gate {
> #define BXT_DRAM_SIZE_12GB 0x3
> #define BXT_DRAM_SIZE_16GB 0x4
>
> +#define SKL_MEMORY_FREQ_MULTIPLIER_HZ 266666666
> +#define SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5E04)
> +#define SKL_REQ_DATA_MASK (0xF << 0)
> +
> +#define SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x500C)
> +#define SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5010)
> +#define SKL_DRAM_SIZE_MASK 0x3F
> +#define SKL_DRAM_SIZE_L_SHIFT 0
> +#define SKL_DRAM_SIZE_S_SHIFT 16
> +#define SKL_DRAM_WIDTH_MASK 0x3
> +#define SKL_DRAM_WIDTH_L_SHIFT 8
> +#define SKL_DRAM_WIDTH_S_SHIFT 24
> +#define SKL_DRAM_WIDTH_X8 0x0
> +#define SKL_DRAM_WIDTH_X16 0x1
> +#define SKL_DRAM_WIDTH_X32 0x2
> +#define SKL_DRAM_RANK_MASK 0x1
> +#define SKL_DRAM_RANK_L_SHIFT 10
> +#define SKL_DRAM_RANK_S_SHIFT 26
> +#define SKL_DRAM_RANK_SINGLE 0x0
> +#define SKL_DRAM_RANK_DUAL 0x1
again, spec pointers please.
> +
> /* Please see hsw_read_dcomp() and hsw_write_dcomp() before using this register,
> * since on HSW we can't write to it using I915_WRITE. */
> #define D_COMP_HSW _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5F0C)
> --
> 2.16.2
>
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