[Intel-gfx] [PATCH 1/5] drm/i915/bxt: Decode memory bandwidth and parameters
Rodrigo Vivi
rodrigo.vivi at intel.com
Thu Aug 16 22:29:47 UTC 2018
On Thu, Jul 26, 2018 at 07:44:06PM +0530, Mahesh Kumar wrote:
> This patch adds support to decode system memory bandwidth and other
> parameters for broxton platform, which will be used for arbitrated
> display memory bandwidth calculation in GEN9 based platforms and
> WM latency level-0 Work-around calculation on GEN9+ platforms.
>
> Changes since V1:
> - s/memdev_info/dram_info
>
> Signed-off-by: Mahesh Kumar <mahesh1.kumar at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 116 ++++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/i915_drv.h | 11 ++++
> drivers/gpu/drm/i915/i915_reg.h | 30 +++++++++++
> 3 files changed, 157 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 18a45e7a3d7c..16629601c9f4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1070,6 +1070,116 @@ static void intel_sanitize_options(struct drm_i915_private *dev_priv)
> intel_gvt_sanitize_options(dev_priv);
> }
>
> +static int
> +bxt_get_dram_info(struct drm_i915_private *dev_priv)
> +{
> + struct dram_info *dram_info = &dev_priv->dram_info;
> + u32 dram_channels;
> + u32 mem_freq_khz, val;
> + u8 num_active_channels;
> + int i;
> +
> + val = I915_READ(BXT_P_CR_MC_BIOS_REQ_0_0_0);
> + mem_freq_khz = DIV_ROUND_UP((val & BXT_REQ_DATA_MASK) *
> + BXT_MEMORY_FREQ_MULTIPLIER_HZ, 1000);
> +
> + dram_channels = (val >> BXT_DRAM_CHANNEL_ACTIVE_SHIFT) &
> + BXT_DRAM_CHANNEL_ACTIVE_MASK;
> + num_active_channels = hweight32(dram_channels);
> +
> + /* Each active bit represents 4-byte channel */
> + dram_info->bandwidth_kbps = (mem_freq_khz * num_active_channels * 4);
> +
> + if (dram_info->bandwidth_kbps == 0) {
> + DRM_INFO("Couldn't get system memory bandwidth\n");
> + return -EINVAL;
> + }
> +
> + /*
> + * Now read each DUNIT8/9/10/11 to check the rank of each dimms.
> + */
> + for (i = BXT_D_CR_DRP0_DUNIT_START; i <= BXT_D_CR_DRP0_DUNIT_END; i++) {
> + u8 rank, size, width;
> + enum dram_rank ch_rank;
> +
> + val = I915_READ(BXT_D_CR_DRP0_DUNIT(i));
> + if (val == 0xFFFFFFFF)
why? any spec or any comment here?
> + continue;
> +
> + dram_info->num_channels++;
> + rank = val & BXT_DRAM_RANK_MASK;
> + width = (val >> BXT_DRAM_WIDTH_SHIFT) & BXT_DRAM_WIDTH_MASK;
> + size = (val >> BXT_DRAM_SIZE_SHIFT) & BXT_DRAM_SIZE_MASK;
> + if (rank == BXT_DRAM_RANK_SINGLE)
> + ch_rank = I915_DRAM_RANK_SINGLE;
> + else if (rank == BXT_DRAM_RANK_DUAL)
> + ch_rank = I915_DRAM_RANK_DUAL;
> + else
> + ch_rank = I915_DRAM_RANK_INVALID;
> +
> + if (size == BXT_DRAM_SIZE_4GB)
> + size = 4;
> + else if (size == BXT_DRAM_SIZE_6GB)
> + size = 6;
> + else if (size == BXT_DRAM_SIZE_8GB)
> + size = 8;
> + else if (size == BXT_DRAM_SIZE_12GB)
> + size = 12;
> + else if (size == BXT_DRAM_SIZE_16GB)
> + size = 16;
> + else
> + size = 0;
switch case? or define these BXT_DRAM_SIZE with enums?
> +
> + width = (1 << width) * 8;
> + DRM_DEBUG_KMS("dram size:%dGB width:X%d rank:%s\n", size,
> + width, rank == BXT_DRAM_RANK_SINGLE ? "single" :
> + rank == BXT_DRAM_RANK_DUAL ? "dual" : "unknown");
> +
> + /*
> + * 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 (dram_info->rank == I915_DRAM_RANK_INVALID)
> + dram_info->rank = ch_rank;
> + else if (ch_rank == I915_DRAM_RANK_SINGLE)
> + dram_info->rank = I915_DRAM_RANK_SINGLE;
> + }
> +
> + if (dram_info->rank == I915_DRAM_RANK_INVALID) {
> + DRM_INFO("couldn't get memory rank information\n");
> + return -EINVAL;
> + }
> +
> + dram_info->valid = true;
> + return 0;
> +}
> +
> +static void
> +intel_get_dram_info(struct drm_i915_private *dev_priv)
> +{
> + struct dram_info *dram_info = &dev_priv->dram_info;
> + int ret;
> +
> + dram_info->valid = false;
> + dram_info->rank = I915_DRAM_RANK_INVALID;
> + dram_info->bandwidth_kbps = 0;
> + dram_info->num_channels = 0;
> +
> + if (!IS_BROXTON(dev_priv))
> + return;
I think this should be checked earlier and probably with some
macro NEED_EDRAM_INFO(dev_priv)... to prepare for other platforms
> +
> + ret = bxt_get_dram_info(dev_priv);
> + if (ret)
> + return;
> +
> + DRM_DEBUG_KMS("DRAM bandwidth:%d KBps, total-channels: %u\n",
> + dram_info->bandwidth_kbps, dram_info->num_channels);
> + DRM_DEBUG_KMS("DRAM rank: %s rank\n",
> + (dram_info->rank == I915_DRAM_RANK_DUAL) ?
> + "dual" : "single");
> +}
> +
> /**
> * i915_driver_init_hw - setup state requiring device access
> * @dev_priv: device private
> @@ -1187,6 +1297,12 @@ static int i915_driver_init_hw(struct drm_i915_private *dev_priv)
> goto err_msi;
>
> intel_opregion_setup(dev_priv);
> + /*
> + * Fill the dram structure to get the system raw bandwidth and
> + * dram info. This will be used for memory latency calculation.
> + */
> + intel_get_dram_info(dev_priv);
> +
>
> return 0;
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 0f49f9988dfa..46f942fa7d60 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1904,6 +1904,17 @@ struct drm_i915_private {
> bool distrust_bios_wm;
> } wm;
>
> + struct dram_info {
> + bool valid;
I don't think we need this duplicated and unused "valid" bool.
> + u8 num_channels;
> + enum dram_rank {
> + I915_DRAM_RANK_INVALID = 0,
> + I915_DRAM_RANK_SINGLE,
> + I915_DRAM_RANK_DUAL
> + } rank;
> + u32 bandwidth_kbps;
> + } dram_info;
> +
> struct i915_runtime_pm runtime_pm;
>
> struct {
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 5530c470f30d..66900d027570 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9634,6 +9634,36 @@ enum skl_power_gate {
> #define DC_STATE_DEBUG_MASK_CORES (1 << 0)
> #define DC_STATE_DEBUG_MASK_MEMORY_UP (1 << 1)
>
> +#define BXT_P_CR_MC_BIOS_REQ_0_0_0 _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x7114)
> +#define BXT_REQ_DATA_MASK 0x3F
> +#define BXT_DRAM_CHANNEL_ACTIVE_SHIFT 12
> +#define BXT_DRAM_CHANNEL_ACTIVE_MASK 0xF
> +#define BXT_MEMORY_FREQ_MULTIPLIER_HZ 133333333
> +
> +#define BXT_D_CR_DRP0_DUNIT8 0x1000
> +#define BXT_D_CR_DRP0_DUNIT9 0x1200
> +#define BXT_D_CR_DRP0_DUNIT_START 8
> +#define BXT_D_CR_DRP0_DUNIT_END 11
> +#define BXT_D_CR_DRP0_DUNIT(x) _MMIO(MCHBAR_MIRROR_BASE_SNB + \
> + _PICK_EVEN((x) - 8, BXT_D_CR_DRP0_DUNIT8,\
> + BXT_D_CR_DRP0_DUNIT9))
> +#define BXT_DRAM_RANK_MASK 0x3
> +#define BXT_DRAM_RANK_SINGLE 0x1
> +#define BXT_DRAM_RANK_DUAL 0x3
> +#define BXT_DRAM_WIDTH_MASK 0x3
> +#define BXT_DRAM_WIDTH_SHIFT 4
> +#define BXT_DRAM_WIDTH_X8 0x0
> +#define BXT_DRAM_WIDTH_X16 0x1
> +#define BXT_DRAM_WIDTH_X32 0x2
> +#define BXT_DRAM_WIDTH_X64 0x3
> +#define BXT_DRAM_SIZE_MASK 0x7
> +#define BXT_DRAM_SIZE_SHIFT 6
> +#define BXT_DRAM_SIZE_4GB 0x0
> +#define BXT_DRAM_SIZE_6GB 0x1
> +#define BXT_DRAM_SIZE_8GB 0x2
> +#define BXT_DRAM_SIZE_12GB 0x3
> +#define BXT_DRAM_SIZE_16GB 0x4
could you please share or point me to this spec?
> +
> /* 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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