Re: [PATCH 4/6] drm/msm/adreno: Implement SMEM-based speed bin

Dmitry Baryshkov
2024-04-06T03:23:40Z

On Fri, Apr 05, 2024 at 10:41:32AM +0200, Konrad Dybcio wrote:
> On recent (SM8550+) Snapdragon platforms, the GPU speed bin data is
> abstracted through SMEM, instead of being directly available in a fuse.
>
> Add support for SMEM-based speed binning, which includes getting
> "feature code" and "product code" from said source and parsing them
> to form something that lets us match OPPs against.
>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
> drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 8 +++---
> drivers/gpu/drm/msm/adreno/adreno_device.c | 2 ++
> drivers/gpu/drm/msm/adreno/adreno_gpu.c | 39 +++++++++++++++++++++++++++---
> drivers/gpu/drm/msm/adreno/adreno_gpu.h | 12 ++++++---
> 4 files changed, 51 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index 4cbdfabbcee5..6776fd80f7a6 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -2890,13 +2890,15 @@ static u32 fuse_to_supp_hw(const struct adreno_info *info, u32 fuse)
> return UINT_MAX;
> }
>
> -static int a6xx_set_supported_hw(struct device *dev, const struct adreno_info *info)
> +static int a6xx_set_supported_hw(struct adreno_gpu *adreno_gpu,
> + struct device *dev,
> + const struct adreno_info *info)
> {
> u32 supp_hw;
> u32 speedbin;
> int ret;
>
> - ret = adreno_read_speedbin(dev, &speedbin);
> + ret = adreno_read_speedbin(adreno_gpu, dev, &speedbin);
> /*
> * -ENOENT means that the platform doesn't support speedbin which is
> * fine
> @@ -3056,7 +3058,7 @@ struct msm_gpu *a6xx_gpu_init(struct drm_device *dev)
>
> a6xx_llc_slices_init(pdev, a6xx_gpu, is_a7xx);
>
> - ret = a6xx_set_supported_hw(&pdev->dev, config->info);
> + ret = a6xx_set_supported_hw(adreno_gpu, &pdev->dev, config->info);
> if (ret) {
> a6xx_destroy(&(a6xx_gpu->base.base));
> return ERR_PTR(ret);
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
> index c3703a51287b..901ef767e491 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
> @@ -6,6 +6,8 @@
> * Copyright (c) 2014,2017 The Linux Foundation. All rights reserved.
> */
>
> +#include <linux/soc/qcom/socinfo.h>
> +
> #include "adreno_gpu.h"
>
> bool hang_debug = false;
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index 074fb498706f..0e4ff532ac3c 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -21,6 +21,9 @@
> #include "msm_gem.h"
> #include "msm_mmu.h"
>
> +#include <linux/soc/qcom/smem.h>
> +#include <linux/soc/qcom/socinfo.h>
> +
> static u64 address_space_size = 0;
> MODULE_PARM_DESC(address_space_size, "Override for size of processes private GPU address space");
> module_param(address_space_size, ullong, 0600);
> @@ -1057,9 +1060,37 @@ void adreno_gpu_ocmem_cleanup(struct adreno_ocmem *adreno_ocmem)
> adreno_ocmem->hdl);
> }
>
> -int adreno_read_speedbin(struct device *dev, u32 *speedbin)
> +int adreno_read_speedbin(struct adreno_gpu *adreno_gpu,
> + struct device *dev, u32 *speedbin)
> {
> - return nvmem_cell_read_variable_le_u32(dev, "speed_bin", speedbin);
> + u32 fcode, pcode;
> + int ret;
> +
> + /* Try reading the speedbin via a nvmem cell first */
> + ret = nvmem_cell_read_variable_le_u32(dev, "speed_bin", speedbin);
> + if (!ret && ret != -EINVAL)

This is always false.

> + return ret;
> +
> + ret = qcom_smem_get_feature_code(&fcode);
> + if (ret) {
> + dev_err(dev, "Couldn't get feature code from SMEM!\n");
> + return ret;

This brings in QCOM_SMEM dependency (which is not mentioned in the
Kconfig). Please keep iMX5 hardware in mind, so the dependency should be
optional. Respective functions should be stubbed in the header.

> + }
> +
> + ret = qcom_smem_get_product_code(&pcode);
> + if (ret) {
> + dev_err(dev, "Couldn't get product code from SMEM!\n");
> + return ret;
> + }
> +
> + /* Don't consider fcode for external feature codes */
> + if (fcode <= SOCINFO_FC_EXT_RESERVE)
> + fcode = SOCINFO_FC_UNKNOWN;
> +
> + *speedbin = FIELD_PREP(ADRENO_SKU_ID_PCODE, pcode) |
> + FIELD_PREP(ADRENO_SKU_ID_FCODE, fcode);

What about just asking the qcom_smem for the 'gpu_bin' and hiding gory
details there? It almost feels that handling raw PCODE / FCODE here is
too low-level and a subject to change depending on the socinfo format.

> +
> + return ret;
> }
>
> int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
> @@ -1098,9 +1129,9 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
> devm_pm_opp_set_clkname(dev, "core");
> }
>
> - if (adreno_read_speedbin(dev, &speedbin) || !speedbin)
> + if (adreno_read_speedbin(adreno_gpu, dev, &speedbin) || !speedbin)
> speedbin = 0xffff;
> - adreno_gpu->speedbin = (uint16_t) (0xffff & speedbin);

the &= 0xffff should probably go to the adreno_read_speedbin / nvmem
case. WDYT?

> + adreno_gpu->speedbin = speedbin;
>
> gpu_name = devm_kasprintf(dev, GFP_KERNEL, "%"ADRENO_CHIPID_FMT,
> ADRENO_CHIPID_ARGS(config->chip_id));
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> index 460b399be37b..1770a9e20484 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> @@ -81,7 +81,12 @@ extern const struct adreno_reglist a612_hwcg[], a615_hwcg[], a630_hwcg[], a640_h
> extern const struct adreno_reglist a660_hwcg[], a690_hwcg[], a702_hwcg[], a730_hwcg[], a740_hwcg[];
>
> struct adreno_speedbin {
> - uint16_t fuse;
> + /* <= 16-bit for NVMEM fuses, 32b for SOCID values */
> + uint32_t fuse;
> +#define ADRENO_SKU_ID_PCODE GENMASK(31, 16)
> +#define ADRENO_SKU_ID_FCODE GENMASK(15, 0)
> +#define ADRENO_SKU_ID(pcode, fcode) (pcode << 16 | fcode)
> +
> uint16_t speedbin;
> };
>
> @@ -137,7 +142,7 @@ struct adreno_gpu {
> struct msm_gpu base;
> const struct adreno_info *info;
> uint32_t chip_id;
> - uint16_t speedbin;
> + uint32_t speedbin;
> const struct adreno_gpu_funcs *funcs;
>
> /* interesting register offsets to dump: */
> @@ -520,7 +525,8 @@ int adreno_fault_handler(struct msm_gpu *gpu, unsigned long iova, int flags,
> struct adreno_smmu_fault_info *info, const char *block,
> u32 scratch[4]);
>
> -int adreno_read_speedbin(struct device *dev, u32 *speedbin);
> +int adreno_read_speedbin(struct adreno_gpu *adreno_gpu,
> + struct device *dev, u32 *speedbin);
>
> /*
> * For a5xx and a6xx targets load the zap shader that is used to pull the GPU
>
> --
> 2.40.1
>

--
With best wishes
Dmitry