Commit 1cf596c6 authored by Tomer Tayar's avatar Tomer Tayar Committed by Oded Gabbay
Browse files

habanalabs/gaudi2: configure virtual MSI-X doorbell interface 



Due to a watchdog timer in the LBW path, writes to the MSI-X doorbell
can return sporadic error responses.
To work-around this issue, a virtual MSI-X doorbell on the HBW path is
configured, using the MSI-X AXI slave interface in the PCIe controller.
Upon an access to a configured HBW host address, the controller will
generate MSI-X interrupt instead of treating the access as regular host
memory access.

This patch allocates the dedicate host memory page, and communicate the
address to F/W, so it will configure the relevant address match
registers in the controller, and will use this address to generate MSI-X
interrupts for F/W events.

Following patches will handle other initiators in the device, to move
them to use the virtual MSI-X doorbell.

Signed-off-by: default avatarTomer Tayar <ttayar@habana.ai>
Reviewed-by: default avatarOded Gabbay <ogabbay@kernel.org>
Signed-off-by: default avatarOded Gabbay <ogabbay@kernel.org>
parent af2e650b

drivers/misc/habanalabs/gaudi2/gaudi2.c

+20 −3
Original line number Diff line number Diff line
@@ -2673,9 +2673,11 @@ static void gaudi2_scrub_arcs_dccm(struct hl_device *hdev) 


static int gaudi2_late_init(struct hl_device *hdev)

{

	struct gaudi2_device *gaudi2 = hdev->asic_specific;

	int rc;



	rc = hl_fw_send_pci_access_msg(hdev, CPUCP_PACKET_ENABLE_PCI_ACCESS, 0x0);

	rc = hl_fw_send_pci_access_msg(hdev, CPUCP_PACKET_ENABLE_PCI_ACCESS,

					gaudi2->virt_msix_db_dma_addr);

	if (rc) {

		dev_err(hdev->dev, "Failed to enable PCI access from CPU\n");

		return rc;
@@ -2922,6 +2924,7 @@ static inline int gaudi2_get_non_zero_random_int(void) 


static int gaudi2_sw_init(struct hl_device *hdev)

{

	struct asic_fixed_properties *prop = &hdev->asic_prop;

	struct gaudi2_device *gaudi2;

	int i, rc;
@@ -2982,6 +2985,14 @@ static int gaudi2_sw_init(struct hl_device *hdev) 
		goto free_cpu_accessible_dma_pool;

	}



	gaudi2->virt_msix_db_cpu_addr = hl_cpu_accessible_dma_pool_alloc(hdev, prop->pmmu.page_size,

								&gaudi2->virt_msix_db_dma_addr);

	if (!gaudi2->virt_msix_db_cpu_addr) {

		dev_err(hdev->dev, "Failed to allocate DMA memory for virtual MSI-X doorbell\n");

		rc = -ENOMEM;

		goto free_cpu_accessible_dma_pool;

	}



	spin_lock_init(&gaudi2->hw_queues_lock);

	spin_lock_init(&gaudi2->kdma_lock);
@@ -2990,7 +3001,7 @@ static int gaudi2_sw_init(struct hl_device *hdev) 
							GFP_KERNEL | __GFP_ZERO);

	if (!gaudi2->scratchpad_kernel_address) {

		rc = -ENOMEM;

		goto free_cpu_accessible_dma_pool;

		goto free_virt_msix_db_mem;

	}



	gaudi2_user_mapped_blocks_init(hdev);
@@ -2999,15 +3010,18 @@ static int gaudi2_sw_init(struct hl_device *hdev) 
	gaudi2_user_interrupt_setup(hdev);



	hdev->supports_coresight = true;

	hdev->asic_prop.supports_soft_reset = true;

	hdev->supports_sync_stream = true;

	hdev->supports_cb_mapping = true;

	hdev->supports_wait_for_multi_cs = false;



	prop->supports_soft_reset = true;



	hdev->asic_funcs->set_pci_memory_regions(hdev);



	return 0;



free_virt_msix_db_mem:

	hl_cpu_accessible_dma_pool_free(hdev, prop->pmmu.page_size, gaudi2->virt_msix_db_cpu_addr);

free_cpu_accessible_dma_pool:

	gen_pool_destroy(hdev->cpu_accessible_dma_pool);

free_cpu_dma_mem:
@@ -3022,8 +3036,11 @@ static int gaudi2_sw_init(struct hl_device *hdev) 


static int gaudi2_sw_fini(struct hl_device *hdev)

{

	struct asic_fixed_properties *prop = &hdev->asic_prop;

	struct gaudi2_device *gaudi2 = hdev->asic_specific;



	hl_cpu_accessible_dma_pool_free(hdev, prop->pmmu.page_size, gaudi2->virt_msix_db_cpu_addr);



	gen_pool_destroy(hdev->cpu_accessible_dma_pool);



	hl_asic_dma_free_coherent(hdev, HL_CPU_ACCESSIBLE_MEM_SIZE, hdev->cpu_accessible_dma_mem,

drivers/misc/habanalabs/gaudi2/gaudi2P.h

+5 −0
Original line number Diff line number Diff line
@@ -439,6 +439,8 @@ struct dup_block_ctx { 
 *                             currently used for HBW QMAN writes which is

 *                             redundant.

 * @scratchpad_bus_address: scratchpad bus address

 * @virt_msix_db_cpu_addr: host memory page for the virtual MSI-X doorbell.

 * @virt_msix_db_dma_addr: bus address of the page for the virtual MSI-X doorbell.

 * @dram_bar_cur_addr: current address of DRAM PCI bar.

 * @hw_cap_initialized: This field contains a bit per H/W engine. When that

 *                      engine is initialized, that bit is set by the driver to
@@ -499,6 +501,9 @@ struct gaudi2_device { 
	void				*scratchpad_kernel_address;

	dma_addr_t			scratchpad_bus_address;



	void				*virt_msix_db_cpu_addr;

	dma_addr_t			virt_msix_db_dma_addr;



	u64				dram_bar_cur_addr;

	u64				hw_cap_initialized;

	u64				active_hw_arc;

drivers/misc/habanalabs/gaudi2/gaudi2_masks.h

+3 −0
Original line number Diff line number Diff line
@@ -132,4 +132,7 @@ 
#define ROT_MSS_HALT_RSB_MASK	BIT(1)

#define ROT_MSS_HALT_MRSB_MASK	BIT(2)



#define PCIE_DBI_MSIX_ADDRESS_MATCH_LOW_OFF_MSIX_ADDRESS_MATCH_EN_SHIFT	0

#define PCIE_DBI_MSIX_ADDRESS_MATCH_LOW_OFF_MSIX_ADDRESS_MATCH_EN_MASK	0x1



#endif /* GAUDI2_MASKS_H_ */