Re: [PATCH 1/7] drm/amdgpu: Implement DPC recovery

[Luben Tuikov <luben.tuikov@amd.com>]

On 2020-08-26 10:46, Andrey Grodzovsky wrote:
> Add DPC handlers with basic recovery functionality.
> 
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu.h        |   9 ++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 181 ++++++++++++++++++++++++++++-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    |   9 +-
>  3 files changed, 196 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 49ea9fa..3399242 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -49,6 +49,8 @@
>  #include <linux/rbtree.h>
>  #include <linux/hashtable.h>
>  #include <linux/dma-fence.h>
> +#include <linux/pci.h>
> +#include <linux/aer.h>
>  
>  #include <drm/ttm/ttm_bo_api.h>
>  #include <drm/ttm/ttm_bo_driver.h>
> @@ -1263,6 +1265,13 @@ static inline int amdgpu_dm_display_resume(struct amdgpu_device *adev) { return
>  void amdgpu_register_gpu_instance(struct amdgpu_device *adev);
>  void amdgpu_unregister_gpu_instance(struct amdgpu_device *adev);
>  
> +pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev,
> +					   pci_channel_state_t state);
> +pci_ers_result_t amdgpu_pci_mmio_enabled(struct pci_dev *pdev);
> +pci_ers_result_t amdgpu_pci_slot_reset(struct pci_dev *pdev);
> +void amdgpu_pci_resume(struct pci_dev *pdev);
> +
> +
>  #include "amdgpu_object.h"
>  
>  /* used by df_v3_6.c and amdgpu_pmu.c */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 5a948ed..84f8d14 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -350,7 +350,9 @@ uint32_t amdgpu_mm_rreg(struct amdgpu_device *adev, uint32_t reg,
>   *
>   * Returns the 8 bit value from the offset specified.
>   */
> -uint8_t amdgpu_mm_rreg8(struct amdgpu_device *adev, uint32_t offset) {
> +uint8_t amdgpu_mm_rreg8(struct amdgpu_device *adev, uint32_t offset)
> +{
> +
>  	if (offset < adev->rmmio_size)
>  		return (readb(adev->rmmio + offset));
>  	BUG();
> @@ -371,7 +373,9 @@ uint8_t amdgpu_mm_rreg8(struct amdgpu_device *adev, uint32_t offset) {
>   *
>   * Writes the value specified to the offset specified.
>   */
> -void amdgpu_mm_wreg8(struct amdgpu_device *adev, uint32_t offset, uint8_t value) {
> +void amdgpu_mm_wreg8(struct amdgpu_device *adev, uint32_t offset, uint8_t value)
> +{
> +
>  	if (offset < adev->rmmio_size)
>  		writeb(value, adev->rmmio + offset);
>  	else
> @@ -380,6 +384,7 @@ void amdgpu_mm_wreg8(struct amdgpu_device *adev, uint32_t offset, uint8_t value)
>  
>  void static inline amdgpu_mm_wreg_mmio(struct amdgpu_device *adev, uint32_t reg, uint32_t v, uint32_t acc_flags)
>  {
> +
>  	trace_amdgpu_mm_wreg(adev->pdev->device, reg, v);
>  
>  	if ((reg * 4) < adev->rmmio_size)
> @@ -407,6 +412,7 @@ void static inline amdgpu_mm_wreg_mmio(struct amdgpu_device *adev, uint32_t reg,
>  void amdgpu_mm_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v,
>  		    uint32_t acc_flags)
>  {
> +
>  	if (!(acc_flags & AMDGPU_REGS_NO_KIQ) && amdgpu_sriov_runtime(adev))
>  		return amdgpu_kiq_wreg(adev, reg, v);
>  
> @@ -461,6 +467,7 @@ u32 amdgpu_io_rreg(struct amdgpu_device *adev, u32 reg)
>   */
>  void amdgpu_io_wreg(struct amdgpu_device *adev, u32 reg, u32 v)
>  {
> +
>  	if ((reg * 4) < adev->rio_mem_size)
>  		iowrite32(v, adev->rio_mem + (reg * 4));
>  	else {
> @@ -480,6 +487,7 @@ void amdgpu_io_wreg(struct amdgpu_device *adev, u32 reg, u32 v)
>   */
>  u32 amdgpu_mm_rdoorbell(struct amdgpu_device *adev, u32 index)
>  {
> +
>  	if (index < adev->doorbell.num_doorbells) {
>  		return readl(adev->doorbell.ptr + index);
>  	} else {
> @@ -500,6 +508,7 @@ u32 amdgpu_mm_rdoorbell(struct amdgpu_device *adev, u32 index)
>   */
>  void amdgpu_mm_wdoorbell(struct amdgpu_device *adev, u32 index, u32 v)
>  {
> +
>  	if (index < adev->doorbell.num_doorbells) {
>  		writel(v, adev->doorbell.ptr + index);
>  	} else {
> @@ -518,6 +527,7 @@ void amdgpu_mm_wdoorbell(struct amdgpu_device *adev, u32 index, u32 v)
>   */
>  u64 amdgpu_mm_rdoorbell64(struct amdgpu_device *adev, u32 index)
>  {
> +
>  	if (index < adev->doorbell.num_doorbells) {
>  		return atomic64_read((atomic64_t *)(adev->doorbell.ptr + index));
>  	} else {
> @@ -538,6 +548,7 @@ u64 amdgpu_mm_rdoorbell64(struct amdgpu_device *adev, u32 index)
>   */
>  void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v)
>  {
> +
>  	if (index < adev->doorbell.num_doorbells) {
>  		atomic64_set((atomic64_t *)(adev->doorbell.ptr + index), v);
>  	} else {
> @@ -2989,6 +3000,7 @@ static const struct attribute *amdgpu_dev_attributes[] = {
>  	NULL
>  };
>  
> +
>  /**
>   * amdgpu_device_init - initialize the driver
>   *
> @@ -3207,6 +3219,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>  		}
>  	}
>  
> +	pci_enable_pcie_error_reporting(adev->ddev.pdev);
> +
> +
>  	/* Post card if necessary */
>  	if (amdgpu_device_need_post(adev)) {
>  		if (!adev->bios) {
> @@ -3359,6 +3374,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>  	if (r)
>  		dev_err(adev->dev, "amdgpu_pmu_init failed\n");
>  
> +	if (pci_save_state(pdev))
> +		DRM_ERROR("Failed to save PCI state!!\n");
> +
>  	return 0;
>  
>  failed:
> @@ -4701,3 +4719,162 @@ int amdgpu_device_baco_exit(struct drm_device *dev)
>  
>  	return 0;
>  }
> +
> +/**
> + * amdgpu_pci_error_detected - Called when a PCI error is detected.
> + * @pdev: PCI device struct
> + * @state: PCI channel state
> + *
> + * Description: Called when a PCI error is detected.
> + *
> + * Return: PCI_ERS_RESULT_NEED_RESET or PCI_ERS_RESULT_DISCONNECT.
> + */
> +pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_state_t state)
> +{
> +	struct drm_device *dev = pci_get_drvdata(pdev);
> +	struct amdgpu_device *adev = drm_to_adev(dev);
> +
> +	DRM_INFO("PCI error: detected callback, state(%d)!!\n", state);
> +
> +	switch (state) {
> +	case pci_channel_io_normal:
> +		return PCI_ERS_RESULT_CAN_RECOVER;
> +	case pci_channel_io_frozen: {
> +		/* Fatal error, prepare for slot reset */
> +
> +		amdgpu_device_lock_adev(adev);
> +		return PCI_ERS_RESULT_NEED_RESET;
> +	}
> +	case pci_channel_io_perm_failure:
> +		/* Permanent error, prepare for device removal */
> +		return PCI_ERS_RESULT_DISCONNECT;
> +	}
> +	return PCI_ERS_RESULT_NEED_RESET;
> +}

Perhaps an empty line before the "return".

> +
> +/**
> + * amdgpu_pci_mmio_enabled - Enable MMIO and dump debug registers
> + * @pdev: pointer to PCI device
> + */
> +pci_ers_result_t amdgpu_pci_mmio_enabled(struct pci_dev *pdev)
> +{
> +
> +	DRM_INFO("PCI error: mmio enabled callback!!\n");
> +
> +	/* TODO - dump whatever for debugging purposes */
> +
> +	/* This called only if amdgpu_pci_error_detected returns
> +	 * PCI_ERS_RESULT_CAN_RECOVER. Read/write to the device still
> +	 * works, no need to reset slot.
> +	 */
> +
> +	return PCI_ERS_RESULT_RECOVERED;
> +}
> +
> +/**
> + * amdgpu_pci_slot_reset - Called when PCI slot has been reset.
> + * @pdev: PCI device struct
> + *
> + * Description: This routine is called by the pci error recovery
> + * code after the PCI slot has been reset, just before we
> + * should resume normal operations.
> + */
> +pci_ers_result_t amdgpu_pci_slot_reset(struct pci_dev *pdev)
> +{
> +	struct drm_device *dev = pci_get_drvdata(pdev);
> +	struct amdgpu_device *adev = drm_to_adev(dev);
> +	int r;
> +	bool vram_lost;
> +
> +	DRM_INFO("PCI error: slot reset callback!!\n");
> +
> +	pci_restore_state(pdev);
> +
> +	r = amdgpu_device_ip_suspend(adev);
> +	if (r)
> +		goto out;
> +
> +
> +	/* post card */
> +	r = amdgpu_atom_asic_init(adev->mode_info.atom_context);
> +	if (r)
> +		goto out;
> +
> +	r = amdgpu_device_ip_resume_phase1(adev);
> +	if (r)
> +		goto out;
> +
> +	vram_lost = amdgpu_device_check_vram_lost(adev);
> +	if (vram_lost) {
> +		DRM_INFO("VRAM is lost due to GPU reset!\n");
> +		amdgpu_inc_vram_lost(adev);
> +	}
> +
> +	r = amdgpu_gtt_mgr_recover(
> +		&adev->mman.bdev.man[TTM_PL_TT]);
> +	if (r)
> +		goto out;
> +
> +	r = amdgpu_device_fw_loading(adev);
> +	if (r)
> +		return r;
> +
> +	r = amdgpu_device_ip_resume_phase2(adev);
> +	if (r)
> +		goto out;
> +
> +	if (vram_lost)
> +		amdgpu_device_fill_reset_magic(adev);
> +
> +	/*
> +	 * Add this ASIC as tracked as reset was already
> +	 * complete successfully.
> +	 */
> +	amdgpu_register_gpu_instance(adev);
> +
> +	r = amdgpu_device_ip_late_init(adev);
> +	if (r)
> +		goto out;
> +
> +	amdgpu_fbdev_set_suspend(adev, 0);
> +
> +	/* must succeed. */
> +	amdgpu_ras_resume(adev);
> +
> +
> +	amdgpu_irq_gpu_reset_resume_helper(adev);
> +	r = amdgpu_ib_ring_tests(adev);
> +	if (r)
> +		goto out;
> +
> +	r = amdgpu_device_recover_vram(adev);
> +
> +out:
> +
> +	if (!r)
> +		DRM_INFO("PCIe error recovery succeeded\n");
> +	else {
> +		DRM_ERROR("PCIe error recovery failed, err:%d", r);
> +		amdgpu_device_unlock_adev(adev);
> +	}

Add braces around the "if ()" if you're going to add them
around the "else".

It's a good idea to run patches through checkpatch.pl--as
a general guidance--sometimes it finds good things.

Regards,
Luben

> +
> +	return r ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
> +}
> +
> +/**
> + * amdgpu_pci_resume() - resume normal ops after PCI reset
> + * @pdev: pointer to PCI device
> + *
> + * Called when the error recovery driver tells us that its
> + * OK to resume normal operation. Use completion to allow
> + * halted scsi ops to resume.
> + */
> +void amdgpu_pci_resume(struct pci_dev *pdev)
> +{
> +	struct drm_device *dev = pci_get_drvdata(pdev);
> +	struct amdgpu_device *adev = drm_to_adev(dev);
> +
> +	amdgpu_device_unlock_adev(adev);
> +
> +	DRM_INFO("PCI error: resume callback!!\n");
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index d984c6a..4bbcc70 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -31,7 +31,6 @@
>  #include <drm/drm_pciids.h>
>  #include <linux/console.h>
>  #include <linux/module.h>
> -#include <linux/pci.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/vga_switcheroo.h>
>  #include <drm/drm_probe_helper.h>
> @@ -1534,6 +1533,13 @@ static struct drm_driver kms_driver = {
>  	.patchlevel = KMS_DRIVER_PATCHLEVEL,
>  };
>  
> +static struct pci_error_handlers amdgpu_pci_err_handler = {
> +	.error_detected	= amdgpu_pci_error_detected,
> +	.mmio_enabled	= amdgpu_pci_mmio_enabled,
> +	.slot_reset	= amdgpu_pci_slot_reset,
> +	.resume		= amdgpu_pci_resume,
> +};
> +
>  static struct pci_driver amdgpu_kms_pci_driver = {
>  	.name = DRIVER_NAME,
>  	.id_table = pciidlist,
> @@ -1541,6 +1547,7 @@ static struct pci_driver amdgpu_kms_pci_driver = {
>  	.remove = amdgpu_pci_remove,
>  	.shutdown = amdgpu_pci_shutdown,
>  	.driver.pm = &amdgpu_pm_ops,
> +	.err_handler = &amdgpu_pci_err_handler,
>  };
>  
>  static int __init amdgpu_init(void)
> 

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