Commit 1f3f7681 authored by Niklas Schnelle's avatar Niklas Schnelle Committed by Heiko Carstens
Browse files

s390/pci: improve DMA translation init and exit 



Currently zpci_dma_init_device()/zpci_dma_exit_device() is called as
part of zpci_enable_device()/zpci_disable_device() and errors for
zpci_dma_exit_device() are always ignored even if we could abort.

Improve upon this by moving zpci_dma_exit_device() out of
zpci_disable_device() and check for errors whenever we have a way to
abort the current operation. Note that for example in
zpci_event_hard_deconfigured() the device is expected to be gone so we
really can't abort and proceed even in case of error.

Similarly move the cc == 3 special case out of zpci_unregister_ioat()
and into the callers allowing to abort when finding an already disabled
devices precludes proceeding with the operation.

While we are at it log IOAT register/unregister errors in the s390
debugfs log,

Reviewed-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent cc049eec

arch/s390/include/asm/pci.h

+2 −0
Original line number Diff line number Diff line
@@ -272,6 +272,8 @@ struct zpci_dev *get_zdev_by_fid(u32); 
/* DMA */

int zpci_dma_init(void);

void zpci_dma_exit(void);

int zpci_dma_init_device(struct zpci_dev *zdev);

int zpci_dma_exit_device(struct zpci_dev *zdev);



/* IRQ */

int __init zpci_irq_init(void);

arch/s390/include/asm/pci_dma.h

+0 −2
Original line number Diff line number Diff line
@@ -182,8 +182,6 @@ static inline unsigned long *get_st_pto(unsigned long entry) 
}



/* Prototypes */

int zpci_dma_init_device(struct zpci_dev *);

void zpci_dma_exit_device(struct zpci_dev *);

void dma_free_seg_table(unsigned long);

unsigned long *dma_alloc_cpu_table(void);

void dma_cleanup_tables(unsigned long *);

arch/s390/pci/pci.c

+19 −24
Original line number Diff line number Diff line
@@ -113,13 +113,16 @@ int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas, 
{

	u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, ZPCI_MOD_FC_REG_IOAT);

	struct zpci_fib fib = {0};

	u8 status;

	u8 cc, status;



	WARN_ON_ONCE(iota & 0x3fff);

	fib.pba = base;

	fib.pal = limit;

	fib.iota = iota | ZPCI_IOTA_RTTO_FLAG;

	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;

	cc = zpci_mod_fc(req, &fib, &status);

	if (cc)

		zpci_dbg(3, "reg ioat fid:%x, cc:%d, status:%d\n", zdev->fid, cc, status);

	return cc;

}



/* Modify PCI: Unregister I/O address translation parameters */
@@ -130,9 +133,9 @@ int zpci_unregister_ioat(struct zpci_dev *zdev, u8 dmaas) 
	u8 cc, status;



	cc = zpci_mod_fc(req, &fib, &status);

	if (cc == 3) /* Function already gone. */

		cc = 0;

	return cc ? -EIO : 0;

	if (cc)

		zpci_dbg(3, "unreg ioat fid:%x, cc:%d, status:%d\n", zdev->fid, cc, status);

	return cc;

}



/* Modify PCI: Set PCI function measurement parameters */
@@ -654,23 +657,11 @@ void zpci_free_domain(int domain) 
int zpci_enable_device(struct zpci_dev *zdev)

{

	u32 fh = zdev->fh;

	int rc;

	int rc = 0;



	if (clp_enable_fh(zdev, &fh, ZPCI_NR_DMA_SPACES)) {

	if (clp_enable_fh(zdev, &fh, ZPCI_NR_DMA_SPACES))

		rc = -EIO;

		goto out;

	}

	zdev->fh = fh;



	rc = zpci_dma_init_device(zdev);

	if (rc)

		goto out_dma;



	return 0;



out_dma:

	clp_disable_fh(zdev, &fh);

out:

	else

		zdev->fh = fh;

	return rc;

}
@@ -680,9 +671,6 @@ int zpci_disable_device(struct zpci_dev *zdev) 
	u32 fh = zdev->fh;

	int cc, rc = 0;



	zpci_dma_exit_device(zdev);

	if (!zdev_enabled(zdev))

		return 0;

	cc = clp_disable_fh(zdev, &fh);

	if (!cc) {

		zdev->fh = fh;
@@ -808,6 +796,11 @@ int zpci_deconfigure_device(struct zpci_dev *zdev) 
	if (zdev->zbus->bus)

		zpci_bus_remove_device(zdev, false);



	if (zdev->dma_table) {

		rc = zpci_dma_exit_device(zdev);

		if (rc)

			return rc;

	}

	if (zdev_enabled(zdev)) {

		rc = zpci_disable_device(zdev);

		if (rc)
@@ -831,6 +824,8 @@ void zpci_release_device(struct kref *kref) 
	if (zdev->zbus->bus)

		zpci_bus_remove_device(zdev, false);



	if (zdev->dma_table)

		zpci_dma_exit_device(zdev);

	if (zdev_enabled(zdev))

		zpci_disable_device(zdev);

arch/s390/pci/pci_bus.c

+5 −0
Original line number Diff line number Diff line
@@ -49,6 +49,11 @@ static int zpci_bus_prepare_device(struct zpci_dev *zdev) 
		rc = zpci_enable_device(zdev);

		if (rc)

			return rc;

		rc = zpci_dma_init_device(zdev);

		if (rc) {

			zpci_disable_device(zdev);

			return rc;

		}

	}



	if (!zdev->has_resources) {

arch/s390/pci/pci_dma.c

+17 −8
Original line number Diff line number Diff line
@@ -590,10 +590,11 @@ int zpci_dma_init_device(struct zpci_dev *zdev) 
		}



	}

	rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,

				(u64) zdev->dma_table);

	if (rc)

	if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,

			       (u64)zdev->dma_table)) {

		rc = -EIO;

		goto free_bitmap;

	}



	return 0;

free_bitmap:
@@ -608,17 +609,25 @@ int zpci_dma_init_device(struct zpci_dev *zdev) 
	return rc;

}



void zpci_dma_exit_device(struct zpci_dev *zdev)

int zpci_dma_exit_device(struct zpci_dev *zdev)

{

	int cc = 0;



	/*

	 * At this point, if the device is part of an IOMMU domain, this would

	 * be a strong hint towards a bug in the IOMMU API (common) code and/or

	 * simultaneous access via IOMMU and DMA API. So let's issue a warning.

	 */

	WARN_ON(zdev->s390_domain);



	if (zpci_unregister_ioat(zdev, 0))

		return;

	if (zdev_enabled(zdev))

		cc = zpci_unregister_ioat(zdev, 0);

	/*

	 * cc == 3 indicates the function is gone already. This can happen

	 * if the function was deconfigured/disabled suddenly and we have not

	 * received a new handle yet.

	 */

	if (cc && cc != 3)

		return -EIO;



	dma_cleanup_tables(zdev->dma_table);

	zdev->dma_table = NULL;
@@ -626,8 +635,8 @@ void zpci_dma_exit_device(struct zpci_dev *zdev) 
	zdev->iommu_bitmap = NULL;

	vfree(zdev->lazy_bitmap);

	zdev->lazy_bitmap = NULL;



	zdev->next_bit = 0;

	return 0;

}



static int __init dma_alloc_cpu_table_caches(void)