From: Alexandru Dadu <[email protected]> The "gpuid" module parameter is used to override the gpuid read from a hardware register and is useful for testing the loading of different firmware (including processing of the firmware header) without having the hardware to hand.
Signed-off-by: Alexandru Dadu <[email protected]> Signed-off-by: Matt Coster <[email protected]> --- drivers/gpu/drm/imagination/pvr_device.c | 117 ++++++++++++++++++++++++++++--- drivers/gpu/drm/imagination/pvr_device.h | 7 +- 2 files changed, 114 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c index abe8ad1d447ac..db844e4e2e945 100644 --- a/drivers/gpu/drm/imagination/pvr_device.c +++ b/drivers/gpu/drm/imagination/pvr_device.c @@ -421,23 +421,21 @@ pvr_request_firmware(struct pvr_device *pvr_dev) } /** - * pvr_load_gpu_id() - Load a PowerVR device's GPU ID (BVNC) from control registers. + * pvr_gpuid_decode_reg() - Decode the GPU ID from GPU register * - * Sets struct pvr_dev.gpu_id. + * Sets the b, v, n, c fields of struct pvr_dev.gpu_id. * * @pvr_dev: Target PowerVR device. + * @gpu_id: Output to be updated with the GPU ID. */ static void -pvr_load_gpu_id(struct pvr_device *pvr_dev) +pvr_gpuid_decode_reg(const struct pvr_device *pvr_dev, struct pvr_gpu_id *gpu_id) { - struct pvr_gpu_id *gpu_id = &pvr_dev->gpu_id; - u64 bvnc; - /* * Try reading the BVNC using the newer (cleaner) method first. If the * B value is zero, fall back to the older method. */ - bvnc = pvr_cr_read64(pvr_dev, ROGUE_CR_CORE_ID__PBVNC); + u64 bvnc = pvr_cr_read64(pvr_dev, ROGUE_CR_CORE_ID__PBVNC); gpu_id->b = PVR_CR_FIELD_GET(bvnc, CORE_ID__PBVNC__BRANCH_ID); if (gpu_id->b != 0) { @@ -456,6 +454,107 @@ pvr_load_gpu_id(struct pvr_device *pvr_dev) } } +/** + * pvr_gpuid_decode_string() - Decode the GPU ID from a module input string + * + * Sets the b, v, n, c fields of struct pvr_dev.gpu_id. + * + * @pvr_dev: Target PowerVR device. + * @param_bvnc: GPU ID (BVNC) module parameter. + * @gpu_id: Output to be updated with the GPU ID. + */ +static int +pvr_gpuid_decode_string(const struct pvr_device *pvr_dev, + const char *param_bvnc, struct pvr_gpu_id *gpu_id) +{ + const struct drm_device *drm_dev = &pvr_dev->base; + char str_cpy[PVR_GPUID_STRING_MAX_LENGTH]; + char *pos, *tkn; + int ret, idx = 0; + u16 user_bvnc_u16[4]; + u8 dot_cnt = 0; + + ret = strscpy(str_cpy, param_bvnc); + + /* + * strscpy() should return at least a size 7 for the input to be valid. + * Returns -E2BIG for the case when the string is empty or too long. + */ + if (ret < PVR_GPUID_STRING_MIN_LENGTH) { + drm_info(drm_dev, + "Invalid size of the input GPU ID (BVNC): %s", + str_cpy); + return -EINVAL; + } + + while (*param_bvnc) { + if (*param_bvnc == '.') + dot_cnt++; + param_bvnc++; + } + + if (dot_cnt != 3) { + drm_info(drm_dev, + "Invalid format of the input GPU ID (BVNC): %s", + str_cpy); + return -EINVAL; + } + + pos = str_cpy; + + while ((tkn = strsep(&pos, ".")) != NULL && idx < 4) { + /* kstrtou16() will also handle the case of consecutive dots */ + ret = kstrtou16(tkn, 10, &user_bvnc_u16[idx]); + if (ret) { + drm_info(drm_dev, + "Invalid format of the input GPU ID (BVNC): %s", + str_cpy); + return -EINVAL; + } + idx++; + } + + gpu_id->b = user_bvnc_u16[0]; + gpu_id->v = user_bvnc_u16[1]; + gpu_id->n = user_bvnc_u16[2]; + gpu_id->c = user_bvnc_u16[3]; + + return 0; +} + +static char *pvr_gpuid_override; +module_param_named(gpuid, pvr_gpuid_override, charp, 0400); +MODULE_PARM_DESC(gpuid, "GPU ID (BVNC) to be used instead of the value read from hardware."); + +/** + * pvr_load_gpu_id() - Load a PowerVR device's GPU ID (BVNC) from control + * registers or input parameter. The input parameter is processed instead + * of the GPU register if provided. + * + * Sets the arch field of struct pvr_dev.gpu_id. + * + * @pvr_dev: Target PowerVR device. + */ +static int +pvr_load_gpu_id(struct pvr_device *pvr_dev) +{ + struct pvr_gpu_id *gpu_id = &pvr_dev->gpu_id; + + if (!pvr_gpuid_override || !pvr_gpuid_override[0]) { + pvr_gpuid_decode_reg(pvr_dev, gpu_id); + } else { + drm_warn(from_pvr_device(pvr_dev), + "Using custom GPU ID (BVNC) provided by the user!"); + + int err = pvr_gpuid_decode_string(pvr_dev, pvr_gpuid_override, + gpu_id); + if (err) + return err; + } + + return 0; +} + /** * pvr_set_dma_info() - Set PowerVR device DMA information * @pvr_dev: Target PowerVR device. @@ -516,7 +615,9 @@ pvr_device_gpu_init(struct pvr_device *pvr_dev) { int err; - pvr_load_gpu_id(pvr_dev); + err = pvr_load_gpu_id(pvr_dev); + if (err) + return err; err = pvr_request_firmware(pvr_dev); if (err) diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h index d0e61923fd9b4..5608a977f6d21 100644 --- a/drivers/gpu/drm/imagination/pvr_device.h +++ b/drivers/gpu/drm/imagination/pvr_device.h @@ -39,6 +39,9 @@ struct firmware; /* Forward declaration from <linux/pwrseq/consumer.h> */ struct pwrseq_desc; +#define PVR_GPUID_STRING_MIN_LENGTH 7U +#define PVR_GPUID_STRING_MAX_LENGTH 32U + /** * struct pvr_gpu_id - Hardware GPU ID information for a PowerVR device * @b: Branch ID. @@ -558,7 +561,7 @@ pvr_device_has_feature(struct pvr_device *pvr_dev, u32 feature); * Return: The value of the requested register. */ static __always_inline u32 -pvr_cr_read32(struct pvr_device *pvr_dev, u32 reg) +pvr_cr_read32(const struct pvr_device *pvr_dev, u32 reg) { return ioread32(pvr_dev->regs + reg); } @@ -571,7 +574,7 @@ pvr_cr_read32(struct pvr_device *pvr_dev, u32 reg) * Return: The value of the requested register. */ static __always_inline u64 -pvr_cr_read64(struct pvr_device *pvr_dev, u32 reg) +pvr_cr_read64(const struct pvr_device *pvr_dev, u32 reg) { return ioread64(pvr_dev->regs + reg); } -- 2.52.0
