Commit be227f8e authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
Browse files

iommu/amd: Tidy up DMA ops init 



Now that DMA ops are part of the core API via iommu-dma, fold the
vestigial remains of the IOMMU_DMA_OPS init state into the IOMMU API
phase, and clean up a few other leftovers. This should also close the
race window wherein bus_set_iommu() effectively makes the DMA ops state
visible before its nominal initialisation - it seems this was previously
fairly benign, but since commit a250c23f ("iommu: remove
DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE") it can now lead to the strict flush
queue policy inadvertently being picked for default domains allocated
during that window, with a corresponding unexpected perfomance impact.

Reported-by: default avatarJussi Maki <joamaki@gmail.com>
Tested-by: default avatarJussi Maki <joamaki@gmail.com>
Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Fixes: a250c23f ("iommu: remove DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE")
Link: https://lore.kernel.org/r/665db61e23ff8d54ac5eb391bef520b3a803fcb9.1622727974.git.robin.murphy@arm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 8124c8a6

drivers/iommu/amd/amd_iommu.h

+0 −2
Original line number Diff line number Diff line
@@ -11,8 +11,6 @@ 


#include "amd_iommu_types.h"



extern int amd_iommu_init_dma_ops(void);

extern int amd_iommu_init_passthrough(void);

extern irqreturn_t amd_iommu_int_thread(int irq, void *data);

extern irqreturn_t amd_iommu_int_handler(int irq, void *data);

extern void amd_iommu_apply_erratum_63(u16 devid);

drivers/iommu/amd/init.c

+0 −5
Original line number Diff line number Diff line
@@ -231,7 +231,6 @@ enum iommu_init_state { 
	IOMMU_ENABLED,

	IOMMU_PCI_INIT,

	IOMMU_INTERRUPTS_EN,

	IOMMU_DMA_OPS,

	IOMMU_INITIALIZED,

	IOMMU_NOT_FOUND,

	IOMMU_INIT_ERROR,
@@ -2895,10 +2894,6 @@ static int __init state_next(void) 
		init_state = ret ? IOMMU_INIT_ERROR : IOMMU_INTERRUPTS_EN;

		break;

	case IOMMU_INTERRUPTS_EN:

		ret = amd_iommu_init_dma_ops();

		init_state = ret ? IOMMU_INIT_ERROR : IOMMU_DMA_OPS;

		break;

	case IOMMU_DMA_OPS:

		init_state = IOMMU_INITIALIZED;

		break;

	case IOMMU_INITIALIZED:

drivers/iommu/amd/iommu.c

+13 −18
Original line number Diff line number Diff line
@@ -30,7 +30,6 @@ 
#include <linux/msi.h>

#include <linux/irqdomain.h>

#include <linux/percpu.h>

#include <linux/iova.h>

#include <linux/io-pgtable.h>

#include <asm/irq_remapping.h>

#include <asm/io_apic.h>
@@ -1773,13 +1772,22 @@ void amd_iommu_domain_update(struct protection_domain *domain) 
	amd_iommu_domain_flush_complete(domain);

}



static void __init amd_iommu_init_dma_ops(void)

{

	swiotlb = (iommu_default_passthrough() || sme_me_mask) ? 1 : 0;



	if (amd_iommu_unmap_flush)

		pr_info("IO/TLB flush on unmap enabled\n");

	else

		pr_info("Lazy IO/TLB flushing enabled\n");

	iommu_set_dma_strict(amd_iommu_unmap_flush);

}



int __init amd_iommu_init_api(void)

{

	int ret, err = 0;

	int err = 0;



	ret = iova_cache_get();

	if (ret)

		return ret;

	amd_iommu_init_dma_ops();



	err = bus_set_iommu(&pci_bus_type, &amd_iommu_ops);

	if (err)
@@ -1796,19 +1804,6 @@ int __init amd_iommu_init_api(void) 
	return 0;

}



int __init amd_iommu_init_dma_ops(void)

{

	swiotlb        = (iommu_default_passthrough() || sme_me_mask) ? 1 : 0;



	if (amd_iommu_unmap_flush)

		pr_info("IO/TLB flush on unmap enabled\n");

	else

		pr_info("Lazy IO/TLB flushing enabled\n");

	iommu_set_dma_strict(amd_iommu_unmap_flush);

	return 0;



}



/*****************************************************************************

 *

 * The following functions belong to the exported interface of AMD IOMMU