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Commit f626b52d authored by Ohad Ben-Cohen's avatar Ohad Ben-Cohen Committed by Joerg Roedel
Browse files

omap: iommu: migrate to the generic IOMMU API 



Migrate OMAP's iommu driver to the generic IOMMU API, so users can stay
generic, and any generic IOMMU functionality can be developed once
in the generic framework.

Migrate omap's iovmm (virtual memory manager) to the generic IOMMU API,
and adapt omap3isp as needed, so the latter won't break.

The plan is to eventually remove iovmm completely by replacing it
with the (upcoming) IOMMU-based DMA-API.

Tested on OMAP3 (with omap3isp) and OMAP4 (with rpmsg/remoteproc).

Signed-off-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarHiroshi DOYU <Hiroshi.DOYU@nokia.com>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent fcb8ce5c

arch/arm/plat-omap/Kconfig

+3 −1
Original line number Diff line number Diff line
@@ -132,8 +132,10 @@ config OMAP_MBOX_KFIFO_SIZE 
	  This can also be changed at runtime (via the mbox_kfifo_size

	  module parameter).



#can't be tristate; iommu api doesn't support un-registration

config OMAP_IOMMU

	tristate

	bool

	select IOMMU_API



config OMAP_IOMMU_DEBUG

       tristate "Export OMAP IOMMU internals in DebugFS"

arch/arm/plat-omap/include/plat/iommu.h

+2 −3
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ struct iommu { 
	void		*isr_priv;



	unsigned int	refcount;

	struct mutex	iommu_lock;	/* global for this whole object */

	spinlock_t	iommu_lock;	/* global for this whole object */



	/*

	 * We don't change iopgd for a situation like pgd for a task,
@@ -167,8 +167,6 @@ extern void iopgtable_lookup_entry(struct iommu *obj, u32 da, u32 **ppgd, 
extern size_t iopgtable_clear_entry(struct iommu *obj, u32 iova);



extern int iommu_set_da_range(struct iommu *obj, u32 start, u32 end);

extern struct iommu *iommu_get(const char *name);

extern void iommu_put(struct iommu *obj);

extern int iommu_set_isr(const char *name,

			 int (*isr)(struct iommu *obj, u32 da, u32 iommu_errs,

				    void *priv),
@@ -185,5 +183,6 @@ extern int foreach_iommu_device(void *data, 


extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t len);

extern size_t dump_tlb_entries(struct iommu *obj, char *buf, ssize_t len);

struct device *omap_find_iommu_device(const char *name);



#endif /* __MACH_IOMMU_H */

arch/arm/plat-omap/include/plat/iovmm.h

+16 −11
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 
#ifndef __IOMMU_MMAP_H

#define __IOMMU_MMAP_H



#include <linux/iommu.h>



struct iovm_struct {

	struct iommu		*iommu;	/* iommu object which this belongs to */

	u32			da_start; /* area definition */
@@ -71,18 +73,21 @@ struct iovm_struct { 




extern struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da);

extern u32 iommu_vmap(struct iommu *obj, u32 da,

extern u32 iommu_vmap(struct iommu_domain *domain, struct iommu *obj, u32 da,

			const struct sg_table *sgt, u32 flags);

extern struct sg_table *iommu_vunmap(struct iommu *obj, u32 da);

extern u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes,

			   u32 flags);

extern void iommu_vfree(struct iommu *obj, const u32 da);

extern u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,

			u32 flags);

extern void iommu_kunmap(struct iommu *obj, u32 da);

extern u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes,

			   u32 flags);

extern void iommu_kfree(struct iommu *obj, u32 da);

extern struct sg_table *iommu_vunmap(struct iommu_domain *domain,

				struct iommu *obj, u32 da);

extern u32 iommu_vmalloc(struct iommu_domain *domain, struct iommu *obj,

				u32 da, size_t bytes, u32 flags);

extern void iommu_vfree(struct iommu_domain *domain, struct iommu *obj,

				const u32 da);

extern u32 iommu_kmap(struct iommu_domain *domain, struct iommu *obj, u32 da,

				u32 pa, size_t bytes, u32 flags);

extern void iommu_kunmap(struct iommu_domain *domain, struct iommu *obj,

				u32 da);

extern u32 iommu_kmalloc(struct iommu_domain *domain, struct iommu *obj,

				u32 da, size_t bytes, u32 flags);

extern void iommu_kfree(struct iommu_domain *domain, struct iommu *obj, u32 da);



extern void *da_to_va(struct iommu *obj, u32 da);

arch/arm/plat-omap/iommu.c

+266 −42
Original line number Diff line number Diff line
@@ -18,6 +18,9 @@ 
#include <linux/ioport.h>

#include <linux/clk.h>

#include <linux/platform_device.h>

#include <linux/iommu.h>

#include <linux/mutex.h>

#include <linux/spinlock.h>



#include <asm/cacheflush.h>
@@ -30,6 +33,19 @@ 
	     (__i < (n)) && (cr = __iotlb_read_cr((obj), __i), true);	\

	     __i++)



/**

 * struct omap_iommu_domain - omap iommu domain

 * @pgtable:	the page table

 * @iommu_dev:	an omap iommu device attached to this domain. only a single

 *		iommu device can be attached for now.

 * @lock:	domain lock, should be taken when attaching/detaching

 */

struct omap_iommu_domain {

	u32 *pgtable;

	struct iommu *iommu_dev;

	spinlock_t lock;

};



/* accommodate the difference between omap1 and omap2/3 */

static const struct iommu_functions *arch_iommu;
@@ -852,35 +868,55 @@ int iommu_set_da_range(struct iommu *obj, u32 start, u32 end) 
EXPORT_SYMBOL_GPL(iommu_set_da_range);



/**

 * iommu_get - Get iommu handler

 * @name:	target iommu name

 * omap_find_iommu_device() - find an omap iommu device by name

 * @name:	name of the iommu device

 *

 * The generic iommu API requires the caller to provide the device

 * he wishes to attach to a certain iommu domain.

 *

 * Drivers generally should not bother with this as it should just

 * be taken care of by the DMA-API using dev_archdata.

 *

 * This function is provided as an interim solution until the latter

 * materializes, and omap3isp is fully migrated to the DMA-API.

 */

struct device *omap_find_iommu_device(const char *name)

{

	return driver_find_device(&omap_iommu_driver.driver, NULL,

				(void *)name,

				device_match_by_alias);

}

EXPORT_SYMBOL_GPL(omap_find_iommu_device);



/**

 * omap_iommu_attach() - attach iommu device to an iommu domain

 * @dev:	target omap iommu device

 * @iopgd:	page table

 **/

struct iommu *iommu_get(const char *name)

static struct iommu *omap_iommu_attach(struct device *dev, u32 *iopgd)

{

	int err = -ENOMEM;

	struct device *dev;

	struct iommu *obj;



	dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,

				 device_match_by_alias);

	if (!dev)

		return ERR_PTR(-ENODEV);

	struct iommu *obj = to_iommu(dev);



	obj = to_iommu(dev);

	spin_lock(&obj->iommu_lock);



	mutex_lock(&obj->iommu_lock);

	/* an iommu device can only be attached once */

	if (++obj->refcount > 1) {

		dev_err(dev, "%s: already attached!\n", obj->name);

		err = -EBUSY;

		goto err_enable;

	}



	if (obj->refcount++ == 0) {

	obj->iopgd = iopgd;

	err = iommu_enable(obj);

	if (err)

		goto err_enable;

	flush_iotlb_all(obj);

	}



	if (!try_module_get(obj->owner))

		goto err_module;



	mutex_unlock(&obj->iommu_lock);

	spin_unlock(&obj->iommu_lock);



	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);

	return obj;
@@ -890,32 +926,32 @@ struct iommu *iommu_get(const char *name) 
		iommu_disable(obj);

err_enable:

	obj->refcount--;

	mutex_unlock(&obj->iommu_lock);

	spin_unlock(&obj->iommu_lock);

	return ERR_PTR(err);

}

EXPORT_SYMBOL_GPL(iommu_get);



/**

 * iommu_put - Put back iommu handler

 * omap_iommu_detach - release iommu device

 * @obj:	target iommu

 **/

void iommu_put(struct iommu *obj)

static void omap_iommu_detach(struct iommu *obj)

{

	if (!obj || IS_ERR(obj))

		return;



	mutex_lock(&obj->iommu_lock);

	spin_lock(&obj->iommu_lock);



	if (--obj->refcount == 0)

		iommu_disable(obj);



	module_put(obj->owner);



	mutex_unlock(&obj->iommu_lock);

	obj->iopgd = NULL;



	spin_unlock(&obj->iommu_lock);



	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);

}

EXPORT_SYMBOL_GPL(iommu_put);



int iommu_set_isr(const char *name,

		  int (*isr)(struct iommu *obj, u32 da, u32 iommu_errs,
@@ -950,7 +986,6 @@ EXPORT_SYMBOL_GPL(iommu_set_isr); 
static int __devinit omap_iommu_probe(struct platform_device *pdev)

{

	int err = -ENODEV;

	void *p;

	int irq;

	struct iommu *obj;

	struct resource *res;
@@ -974,7 +1009,7 @@ static int __devinit omap_iommu_probe(struct platform_device *pdev) 
	obj->da_start = pdata->da_start;

	obj->da_end = pdata->da_end;



	mutex_init(&obj->iommu_lock);

	spin_lock_init(&obj->iommu_lock);

	mutex_init(&obj->mmap_lock);

	spin_lock_init(&obj->page_table_lock);

	INIT_LIST_HEAD(&obj->mmap);
@@ -1009,22 +1044,9 @@ static int __devinit omap_iommu_probe(struct platform_device *pdev) 
		goto err_irq;

	platform_set_drvdata(pdev, obj);



	p = (void *)__get_free_pages(GFP_KERNEL, get_order(IOPGD_TABLE_SIZE));

	if (!p) {

		err = -ENOMEM;

		goto err_pgd;

	}

	memset(p, 0, IOPGD_TABLE_SIZE);

	clean_dcache_area(p, IOPGD_TABLE_SIZE);

	obj->iopgd = p;



	BUG_ON(!IS_ALIGNED((unsigned long)obj->iopgd, IOPGD_TABLE_SIZE));



	dev_info(&pdev->dev, "%s registered\n", obj->name);

	return 0;



err_pgd:

	free_irq(irq, obj);

err_irq:

	iounmap(obj->regbase);

err_ioremap:
@@ -1045,7 +1067,6 @@ static int __devexit omap_iommu_remove(struct platform_device *pdev) 
	platform_set_drvdata(pdev, NULL);



	iopgtable_clear_entry_all(obj);

	free_pages((unsigned long)obj->iopgd, get_order(IOPGD_TABLE_SIZE));



	irq = platform_get_irq(pdev, 0);

	free_irq(irq, obj);
@@ -1072,6 +1093,207 @@ static void iopte_cachep_ctor(void *iopte) 
	clean_dcache_area(iopte, IOPTE_TABLE_SIZE);

}



static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,

			 phys_addr_t pa, int order, int prot)

{

	struct omap_iommu_domain *omap_domain = domain->priv;

	struct iommu *oiommu = omap_domain->iommu_dev;

	struct device *dev = oiommu->dev;

	size_t bytes = PAGE_SIZE << order;

	struct iotlb_entry e;

	int omap_pgsz;

	u32 ret, flags;



	/* we only support mapping a single iommu page for now */

	omap_pgsz = bytes_to_iopgsz(bytes);

	if (omap_pgsz < 0) {

		dev_err(dev, "invalid size to map: %d\n", bytes);

		return -EINVAL;

	}



	dev_dbg(dev, "mapping da 0x%lx to pa 0x%x size 0x%x\n", da, pa, bytes);



	flags = omap_pgsz | prot;



	iotlb_init_entry(&e, da, pa, flags);



	ret = iopgtable_store_entry(oiommu, &e);

	if (ret) {

		dev_err(dev, "iopgtable_store_entry failed: %d\n", ret);

		return ret;

	}



	return 0;

}



static int omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,

			    int order)

{

	struct omap_iommu_domain *omap_domain = domain->priv;

	struct iommu *oiommu = omap_domain->iommu_dev;

	struct device *dev = oiommu->dev;

	size_t bytes = PAGE_SIZE << order;

	size_t ret;



	dev_dbg(dev, "unmapping da 0x%lx size 0x%x\n", da, bytes);



	ret = iopgtable_clear_entry(oiommu, da);

	if (ret != bytes) {

		dev_err(dev, "entry @ 0x%lx was %d; not %d\n", da, ret, bytes);

		return -EINVAL;

	}



	return 0;

}



static int

omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)

{

	struct omap_iommu_domain *omap_domain = domain->priv;

	struct iommu *oiommu;

	int ret = 0;



	spin_lock(&omap_domain->lock);



	/* only a single device is supported per domain for now */

	if (omap_domain->iommu_dev) {

		dev_err(dev, "iommu domain is already attached\n");

		ret = -EBUSY;

		goto out;

	}



	/* get a handle to and enable the omap iommu */

	oiommu = omap_iommu_attach(dev, omap_domain->pgtable);

	if (IS_ERR(oiommu)) {

		ret = PTR_ERR(oiommu);

		dev_err(dev, "can't get omap iommu: %d\n", ret);

		goto out;

	}



	omap_domain->iommu_dev = oiommu;



out:

	spin_unlock(&omap_domain->lock);

	return ret;

}



static void omap_iommu_detach_dev(struct iommu_domain *domain,

				 struct device *dev)

{

	struct omap_iommu_domain *omap_domain = domain->priv;

	struct iommu *oiommu = to_iommu(dev);



	spin_lock(&omap_domain->lock);



	/* only a single device is supported per domain for now */

	if (omap_domain->iommu_dev != oiommu) {

		dev_err(dev, "invalid iommu device\n");

		goto out;

	}



	iopgtable_clear_entry_all(oiommu);



	omap_iommu_detach(oiommu);



	omap_domain->iommu_dev = NULL;



out:

	spin_unlock(&omap_domain->lock);

}



static int omap_iommu_domain_init(struct iommu_domain *domain)

{

	struct omap_iommu_domain *omap_domain;



	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);

	if (!omap_domain) {

		pr_err("kzalloc failed\n");

		goto out;

	}



	omap_domain->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_KERNEL);

	if (!omap_domain->pgtable) {

		pr_err("kzalloc failed\n");

		goto fail_nomem;

	}



	/*

	 * should never fail, but please keep this around to ensure

	 * we keep the hardware happy

	 */

	BUG_ON(!IS_ALIGNED((long)omap_domain->pgtable, IOPGD_TABLE_SIZE));



	clean_dcache_area(omap_domain->pgtable, IOPGD_TABLE_SIZE);

	spin_lock_init(&omap_domain->lock);



	domain->priv = omap_domain;



	return 0;



fail_nomem:

	kfree(omap_domain);

out:

	return -ENOMEM;

}



/* assume device was already detached */

static void omap_iommu_domain_destroy(struct iommu_domain *domain)

{

	struct omap_iommu_domain *omap_domain = domain->priv;



	domain->priv = NULL;



	kfree(omap_domain->pgtable);

	kfree(omap_domain);

}



static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,

					  unsigned long da)

{

	struct omap_iommu_domain *omap_domain = domain->priv;

	struct iommu *oiommu = omap_domain->iommu_dev;

	struct device *dev = oiommu->dev;

	u32 *pgd, *pte;

	phys_addr_t ret = 0;



	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);



	if (pte) {

		if (iopte_is_small(*pte))

			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);

		else if (iopte_is_large(*pte))

			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);

		else

			dev_err(dev, "bogus pte 0x%x", *pte);

	} else {

		if (iopgd_is_section(*pgd))

			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);

		else if (iopgd_is_super(*pgd))

			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);

		else

			dev_err(dev, "bogus pgd 0x%x", *pgd);

	}



	return ret;

}



static int omap_iommu_domain_has_cap(struct iommu_domain *domain,

				    unsigned long cap)

{

	return 0;

}



static struct iommu_ops omap_iommu_ops = {

	.domain_init	= omap_iommu_domain_init,

	.domain_destroy	= omap_iommu_domain_destroy,

	.attach_dev	= omap_iommu_attach_dev,

	.detach_dev	= omap_iommu_detach_dev,

	.map		= omap_iommu_map,

	.unmap		= omap_iommu_unmap,

	.iova_to_phys	= omap_iommu_iova_to_phys,

	.domain_has_cap	= omap_iommu_domain_has_cap,

};



static int __init omap_iommu_init(void)

{

	struct kmem_cache *p;
@@ -1084,6 +1306,8 @@ static int __init omap_iommu_init(void) 
		return -ENOMEM;

	iopte_cachep = p;



	register_iommu(&omap_iommu_ops);



	return platform_driver_register(&omap_iommu_driver);

}

module_init(omap_iommu_init);

arch/arm/plat-omap/iopgtable.h

+18 −0
Original line number Diff line number Diff line
@@ -56,6 +56,19 @@ 


#define IOPAGE_MASK		IOPTE_MASK



/**

 * omap_iommu_translate() - va to pa translation

 * @d:		omap iommu descriptor

 * @va:		virtual address

 * @mask:	omap iommu descriptor mask

 *

 * va to pa translation

 */

static inline phys_addr_t omap_iommu_translate(u32 d, u32 va, u32 mask)

{

	return (d & mask) | (va & (~mask));

}



/*

 * some descriptor attributes.

 */
@@ -64,10 +77,15 @@ 
#define IOPGD_SUPER		(1 << 18 | 2 << 0)



#define iopgd_is_table(x)	(((x) & 3) == IOPGD_TABLE)

#define iopgd_is_section(x)	(((x) & (1 << 18 | 3)) == IOPGD_SECTION)

#define iopgd_is_super(x)	(((x) & (1 << 18 | 3)) == IOPGD_SUPER)



#define IOPTE_SMALL		(2 << 0)

#define IOPTE_LARGE		(1 << 0)



#define iopte_is_small(x)	(((x) & 2) == IOPTE_SMALL)

#define iopte_is_large(x)	(((x) & 3) == IOPTE_LARGE)



/* to find an entry in a page-table-directory */

#define iopgd_index(da)		(((da) >> IOPGD_SHIFT) & (PTRS_PER_IOPGD - 1))

#define iopgd_offset(obj, da)	((obj)->iopgd + iopgd_index(da))