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Commit 0feae533 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

x86/amd-iommu: Add passthrough mode initialization functions 



When iommu=pt is passed on kernel command line the devices
should run untranslated. This requires the allocation of a
special domain for that purpose. This patch implements the
allocation and initialization path for iommu=pt.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 2650815f

arch/x86/include/asm/amd_iommu.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#ifdef CONFIG_AMD_IOMMU

extern int amd_iommu_init(void);

extern int amd_iommu_init_dma_ops(void);

extern int amd_iommu_init_passthrough(void);

extern void amd_iommu_detect(void);

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

extern void amd_iommu_flush_all_domains(void);

arch/x86/include/asm/amd_iommu_types.h

+4 −0
Original line number Diff line number Diff line
@@ -143,6 +143,7 @@ 
#define EVT_BUFFER_SIZE		8192 /* 512 entries */

#define EVT_LEN_MASK		(0x9ULL << 56)



#define PAGE_MODE_NONE    0x00

#define PAGE_MODE_1_LEVEL 0x01

#define PAGE_MODE_2_LEVEL 0x02

#define PAGE_MODE_3_LEVEL 0x03
@@ -194,6 +195,9 @@ 
#define PD_DMA_OPS_MASK		(1UL << 0) /* domain used for dma_ops */

#define PD_DEFAULT_MASK		(1UL << 1) /* domain is a default dma_ops

					      domain for an IOMMU */

#define PD_PASSTHROUGH_MASK	(1UL << 2) /* domain has no page

					      translation */



extern bool amd_iommu_dump;

#define DUMP_printk(format, arg...)					\

	do {								\

arch/x86/kernel/amd_iommu.c

+64 −8
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ static DEFINE_RWLOCK(amd_iommu_devtable_lock); 
static LIST_HEAD(iommu_pd_list);

static DEFINE_SPINLOCK(iommu_pd_list_lock);



/*

 * Domain for untranslated devices - only allocated

 * if iommu=pt passed on kernel cmd line.

 */

static struct protection_domain *pt_domain;



#ifdef CONFIG_IOMMU_API

static struct iommu_ops amd_iommu_ops;

#endif
@@ -1067,7 +1073,7 @@ static struct protection_domain *domain_for_device(u16 devid) 
 * If a device is not yet associated with a domain, this function does

 * assigns it visible for the hardware

 */

static void attach_device(struct amd_iommu *iommu,

static void __attach_device(struct amd_iommu *iommu,

			    struct protection_domain *domain,

			    u16 devid)

{
@@ -1087,6 +1093,13 @@ static void attach_device(struct amd_iommu *iommu, 


	amd_iommu_pd_table[devid] = domain;

	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);

}



static void attach_device(struct amd_iommu *iommu,

			  struct protection_domain *domain,

			  u16 devid)

{

	__attach_device(iommu, domain, devid);



	/*

	 * We might boot into a crash-kernel here. The crashed kernel
@@ -2219,3 +2232,46 @@ static struct iommu_ops amd_iommu_ops = { 
	.domain_has_cap = amd_iommu_domain_has_cap,

};



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

 *

 * The next functions do a basic initialization of IOMMU for pass through

 * mode

 *

 * In passthrough mode the IOMMU is initialized and enabled but not used for

 * DMA-API translation.

 *

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



int __init amd_iommu_init_passthrough(void)

{

	struct pci_dev *dev = NULL;

	u16 devid, devid2;



	/* allocate passthroug domain */

	pt_domain = protection_domain_alloc();

	if (!pt_domain)

		return -ENOMEM;



	pt_domain->mode |= PAGE_MODE_NONE;



	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {

		struct amd_iommu *iommu;



		devid = calc_devid(dev->bus->number, dev->devfn);

		if (devid > amd_iommu_last_bdf)

			continue;



		devid2 = amd_iommu_alias_table[devid];



		iommu = amd_iommu_rlookup_table[devid2];

		if (!iommu)

			continue;



		__attach_device(iommu, pt_domain, devid);

		__attach_device(iommu, pt_domain, devid2);

	}



	pr_info("AMD-Vi: Initialized for Passthrough Mode\n");



	return 0;

}