| Message ID | 20180424181625.22410-3-hch@lst.de |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [1/5] scsi: reduce use of block bounce buffers | expand |
On 4/24/18 12:16 PM, Christoph Hellwig wrote: > ide_toggle_bounce did select various strange block bounce limits, including > not bouncing at all as soon as an iommu is present in the system. Given > that the dma_map routines now handle any required bounce buffering except > for ISA DMA, and the ide code already must handle either ISA DMA or highmem > at least for iommu equipped systems we can get rid of the block layer > bounce limit setting entirely. Pretty sure I was the one to add this code, when highmem page IO was enabled about two decades ago... Outside of DMA, the issue was that the PIO code could not handle highmem. That's not the case anymore, so this should be fine. Reviewed-by: Jens Axboe <axboe@kernel.dk>
On Tue, Apr 24, 2018 at 08:02:56PM -0600, Jens Axboe wrote: > On 4/24/18 12:16 PM, Christoph Hellwig wrote: > > ide_toggle_bounce did select various strange block bounce limits, including > > not bouncing at all as soon as an iommu is present in the system. Given > > that the dma_map routines now handle any required bounce buffering except > > for ISA DMA, and the ide code already must handle either ISA DMA or highmem > > at least for iommu equipped systems we can get rid of the block layer > > bounce limit setting entirely. > > Pretty sure I was the one to add this code, when highmem page IO was > enabled about two decades ago... > > Outside of DMA, the issue was that the PIO code could not handle > highmem. That's not the case anymore, so this should be fine. Yes, that is the rationale. Any chance to you could look over the other patches as well? Except for the networking one for which I'd really like to see a review from Dave all the users of the interface are block related.
On 4/26/18 1:20 AM, Christoph Hellwig wrote: > On Tue, Apr 24, 2018 at 08:02:56PM -0600, Jens Axboe wrote: >> On 4/24/18 12:16 PM, Christoph Hellwig wrote: >>> ide_toggle_bounce did select various strange block bounce limits, including >>> not bouncing at all as soon as an iommu is present in the system. Given >>> that the dma_map routines now handle any required bounce buffering except >>> for ISA DMA, and the ide code already must handle either ISA DMA or highmem >>> at least for iommu equipped systems we can get rid of the block layer >>> bounce limit setting entirely. >> >> Pretty sure I was the one to add this code, when highmem page IO was >> enabled about two decades ago... >> >> Outside of DMA, the issue was that the PIO code could not handle >> highmem. That's not the case anymore, so this should be fine. > > Yes, that is the rationale. Any chance to you could look over the > other patches as well? Except for the networking one for which I'd > really like to see a review from Dave all the users of the interface > are block related. You can add my reviewed-by to 1-3, and 5. Looks good to me.
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c index 54d4d78ca46a..6f344654ef22 100644 --- a/drivers/ide/ide-dma.c +++ b/drivers/ide/ide-dma.c @@ -180,7 +180,6 @@ EXPORT_SYMBOL_GPL(ide_dma_unmap_sg); void ide_dma_off_quietly(ide_drive_t *drive) { drive->dev_flags &= ~IDE_DFLAG_USING_DMA; - ide_toggle_bounce(drive, 0); drive->hwif->dma_ops->dma_host_set(drive, 0); } @@ -211,7 +210,6 @@ EXPORT_SYMBOL(ide_dma_off); void ide_dma_on(ide_drive_t *drive) { drive->dev_flags |= IDE_DFLAG_USING_DMA; - ide_toggle_bounce(drive, 1); drive->hwif->dma_ops->dma_host_set(drive, 1); } diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c index e1180fa46196..78cb79eddc8b 100644 --- a/drivers/ide/ide-lib.c +++ b/drivers/ide/ide-lib.c @@ -6,32 +6,6 @@ #include <linux/ide.h> #include <linux/bitops.h> -/** - * ide_toggle_bounce - handle bounce buffering - * @drive: drive to update - * @on: on/off boolean - * - * Enable or disable bounce buffering for the device. Drives move - * between PIO and DMA and that changes the rules we need. - */ - -void ide_toggle_bounce(ide_drive_t *drive, int on) -{ - u64 addr = BLK_BOUNCE_HIGH; /* dma64_addr_t */ - - if (!PCI_DMA_BUS_IS_PHYS) { - addr = BLK_BOUNCE_ANY; - } else if (on && drive->media == ide_disk) { - struct device *dev = drive->hwif->dev; - - if (dev && dev->dma_mask) - addr = *dev->dma_mask; - } - - if (drive->queue) - blk_queue_bounce_limit(drive->queue, addr); -} - u64 ide_get_lba_addr(struct ide_cmd *cmd, int lba48) { struct ide_taskfile *tf = &cmd->tf; diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c index 2019e66eada7..8d8ed036ca0a 100644 --- a/drivers/ide/ide-probe.c +++ b/drivers/ide/ide-probe.c @@ -805,9 +805,6 @@ static int ide_init_queue(ide_drive_t *drive) /* assign drive queue */ drive->queue = q; - /* needs drive->queue to be set */ - ide_toggle_bounce(drive, 1); - return 0; } diff --git a/include/linux/ide.h b/include/linux/ide.h index ca9d34feb572..11f0dd03a4b4 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -1508,8 +1508,6 @@ static inline void ide_set_hwifdata (ide_hwif_t * hwif, void *data) hwif->hwif_data = data; } -extern void ide_toggle_bounce(ide_drive_t *drive, int on); - u64 ide_get_lba_addr(struct ide_cmd *, int); u8 ide_dump_status(ide_drive_t *, const char *, u8);
ide_toggle_bounce did select various strange block bounce limits, including not bouncing at all as soon as an iommu is present in the system. Given that the dma_map routines now handle any required bounce buffering except for ISA DMA, and the ide code already must handle either ISA DMA or highmem at least for iommu equipped systems we can get rid of the block layer bounce limit setting entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/ide/ide-dma.c | 2 -- drivers/ide/ide-lib.c | 26 -------------------------- drivers/ide/ide-probe.c | 3 --- include/linux/ide.h | 2 -- 4 files changed, 33 deletions(-)