Commit b60b270b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

swim3: support highmem 



swim3 only uses the virtual address of a bio to stash it into the data
transfer using virt_to_bus.  But the ppc32 virt_to_bus just uses the
physical address with an offset.  Replace virt_to_bus with a local hack
that performs the equivalent transformation and stop asking for block
layer bounce buffering.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406061839.811588-1-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3d86739c

drivers/block/swim3.c

+25 −9
Original line number Original line Diff line number Diff line
@@ -234,7 +234,6 @@ static unsigned short write_postamble[] = { 
};

};





static void seek_track(struct floppy_state *fs, int n);

static void seek_track(struct floppy_state *fs, int n);

static void init_dma(struct dbdma_cmd *cp, int cmd, void *buf, int count);

static void act(struct floppy_state *fs);

static void act(struct floppy_state *fs);

static void scan_timeout(struct timer_list *t);

static void scan_timeout(struct timer_list *t);

static void seek_timeout(struct timer_list *t);

static void seek_timeout(struct timer_list *t);
@@ -404,12 +403,28 @@ static inline void seek_track(struct floppy_state *fs, int n) 
	fs->settle_time = 0;

	fs->settle_time = 0;

}

}





/*

 * XXX: this is a horrible hack, but at least allows ppc32 to get

 * out of defining virt_to_bus, and this driver out of using the

 * deprecated block layer bounce buffering for highmem addresses

 * for no good reason.

 */

static unsigned long swim3_phys_to_bus(phys_addr_t paddr)

{

	return paddr + PCI_DRAM_OFFSET;

}



static phys_addr_t swim3_bio_phys(struct bio *bio)

{

	return page_to_phys(bio_page(bio)) + bio_offset(bio);

}



static inline void init_dma(struct dbdma_cmd *cp, int cmd,

static inline void init_dma(struct dbdma_cmd *cp, int cmd,

			    void *buf, int count)

			    phys_addr_t paddr, int count)

{

{

	cp->req_count = cpu_to_le16(count);

	cp->req_count = cpu_to_le16(count);

	cp->command = cpu_to_le16(cmd);

	cp->command = cpu_to_le16(cmd);

	cp->phy_addr = cpu_to_le32(virt_to_bus(buf));

	cp->phy_addr = cpu_to_le32(swim3_phys_to_bus(paddr));

	cp->xfer_status = 0;

	cp->xfer_status = 0;

}

}
@@ -441,16 +456,18 @@ static inline void setup_transfer(struct floppy_state *fs) 
	out_8(&sw->sector, fs->req_sector);

	out_8(&sw->sector, fs->req_sector);

	out_8(&sw->nsect, n);

	out_8(&sw->nsect, n);

	out_8(&sw->gap3, 0);

	out_8(&sw->gap3, 0);

	out_le32(&dr->cmdptr, virt_to_bus(cp));

	out_le32(&dr->cmdptr, swim3_phys_to_bus(virt_to_phys(cp)));

	if (rq_data_dir(req) == WRITE) {

	if (rq_data_dir(req) == WRITE) {

		/* Set up 3 dma commands: write preamble, data, postamble */

		/* Set up 3 dma commands: write preamble, data, postamble */

		init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));

		init_dma(cp, OUTPUT_MORE, virt_to_phys(write_preamble),

			 sizeof(write_preamble));

		++cp;

		++cp;

		init_dma(cp, OUTPUT_MORE, bio_data(req->bio), 512);

		init_dma(cp, OUTPUT_MORE, swim3_bio_phys(req->bio), 512);

		++cp;

		++cp;

		init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));

		init_dma(cp, OUTPUT_LAST, virt_to_phys(write_postamble),

			sizeof(write_postamble));

	} else {

	} else {

		init_dma(cp, INPUT_LAST, bio_data(req->bio), n * 512);

		init_dma(cp, INPUT_LAST, swim3_bio_phys(req->bio), n * 512);

	}

	}

	++cp;

	++cp;

	out_le16(&cp->command, DBDMA_STOP);

	out_le16(&cp->command, DBDMA_STOP);
@@ -1201,7 +1218,6 @@ static int swim3_attach(struct macio_dev *mdev, 
		disk->queue = NULL;

		disk->queue = NULL;

		goto out_put_disk;

		goto out_put_disk;

	}

	}

	blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);

	disk->queue->queuedata = fs;

	disk->queue->queuedata = fs;





	rc = swim3_add_device(mdev, floppy_count);

	rc = swim3_add_device(mdev, floppy_count);