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Commit 7c53664d authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Linus Torvalds
Browse files

iommu sg merging: alpha: make pci_iommu respect the segment size limits 



This patch makes pci_iommu respect segment size limits when merging sg
lists.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: default avatarJens Axboe <jens.axboe@oracle.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a031bbcb

arch/alpha/kernel/pci_iommu.c

+18 −6
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/bootmem.h>

#include <linux/scatterlist.h>

#include <linux/log2.h>

#include <linux/dma-mapping.h>



#include <asm/io.h>

#include <asm/hwrpb.h>
@@ -470,22 +471,29 @@ EXPORT_SYMBOL(pci_free_consistent); 
#define SG_ENT_PHYS_ADDRESS(SG) __pa(SG_ENT_VIRT_ADDRESS(SG))



static void

sg_classify(struct scatterlist *sg, struct scatterlist *end, int virt_ok)

sg_classify(struct device *dev, struct scatterlist *sg, struct scatterlist *end,

	    int virt_ok)

{

	unsigned long next_paddr;

	struct scatterlist *leader;

	long leader_flag, leader_length;

	unsigned int max_seg_size;



	leader = sg;

	leader_flag = 0;

	leader_length = leader->length;

	next_paddr = SG_ENT_PHYS_ADDRESS(leader) + leader_length;



	/* we will not marge sg without device. */

	max_seg_size = dev ? dma_get_max_seg_size(dev) : 0;

	for (++sg; sg < end; ++sg) {

		unsigned long addr, len;

		addr = SG_ENT_PHYS_ADDRESS(sg);

		len = sg->length;



		if (leader_length + len > max_seg_size)

			goto new_segment;



		if (next_paddr == addr) {

			sg->dma_address = -1;

			leader_length += len;
@@ -494,6 +502,7 @@ sg_classify(struct scatterlist *sg, struct scatterlist *end, int virt_ok) 
			leader_flag = 1;

			leader_length += len;

		} else {

new_segment:

			leader->dma_address = leader_flag;

			leader->dma_length = leader_length;

			leader = sg;
@@ -512,7 +521,7 @@ sg_classify(struct scatterlist *sg, struct scatterlist *end, int virt_ok) 
   in the blanks.  */



static int

sg_fill(struct scatterlist *leader, struct scatterlist *end,

sg_fill(struct device *dev, struct scatterlist *leader, struct scatterlist *end,

	struct scatterlist *out, struct pci_iommu_arena *arena,

	dma_addr_t max_dma, int dac_allowed)

{
@@ -562,8 +571,8 @@ sg_fill(struct scatterlist *leader, struct scatterlist *end, 


		/* Otherwise, break up the remaining virtually contiguous

		   hunks into individual direct maps and retry.  */

		sg_classify(leader, end, 0);

		return sg_fill(leader, end, out, arena, max_dma, dac_allowed);

		sg_classify(dev, leader, end, 0);

		return sg_fill(dev, leader, end, out, arena, max_dma, dac_allowed);

	}



	out->dma_address = arena->dma_base + dma_ofs*PAGE_SIZE + paddr;
@@ -619,12 +628,15 @@ pci_map_sg(struct pci_dev *pdev, struct scatterlist *sg, int nents, 
	struct pci_iommu_arena *arena;

	dma_addr_t max_dma;

	int dac_allowed;

	struct device *dev;



	if (direction == PCI_DMA_NONE)

		BUG();



	dac_allowed = pdev ? pci_dac_dma_supported(pdev, pdev->dma_mask) : 0;



	dev = pdev ? &pdev->dev : NULL;



	/* Fast path single entry scatterlists.  */

	if (nents == 1) {

		sg->dma_length = sg->length;
@@ -638,7 +650,7 @@ pci_map_sg(struct pci_dev *pdev, struct scatterlist *sg, int nents, 
	end = sg + nents;



	/* First, prepare information about the entries.  */

	sg_classify(sg, end, alpha_mv.mv_pci_tbi != 0);

	sg_classify(dev, sg, end, alpha_mv.mv_pci_tbi != 0);



	/* Second, figure out where we're going to map things.  */

	if (alpha_mv.mv_pci_tbi) {
@@ -658,7 +670,7 @@ pci_map_sg(struct pci_dev *pdev, struct scatterlist *sg, int nents, 
	for (out = sg; sg < end; ++sg) {

		if ((int) sg->dma_address < 0)

			continue;

		if (sg_fill(sg, end, out, arena, max_dma, dac_allowed) < 0)

		if (sg_fill(dev, sg, end, out, arena, max_dma, dac_allowed) < 0)

			goto error;

		out++;

	}

include/asm-alpha/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#ifdef __KERNEL__



#include <linux/spinlock.h>

#include <linux/dma-mapping.h>

#include <asm/scatterlist.h>

#include <asm/machvec.h>