Re: [PATCH 17/17] mmc: pass queue_limits to blk_mq_alloc_disk

Geert Uytterhoeven
2024-02-20T22:08:20Z

Hi Christoph,

On Thu, Feb 15, 2024 at 9:16 AM Christoph Hellwig <hch@lst.de> wrote:
> Pass the queue limit set at initialization time directly to
> blk_mq_alloc_disk instead of updating it right after the allocation.
>
> This requires refactoring the code a bit so that what was mmc_setup_queue
> before also allocates the gendisk now and actually sets all limits.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Thanks for your patch, which is now commit 616f876617927732 ("mmc: pass
queue_limits to blk_mq_alloc_disk") in block/for-next.

I have bisected the following failure on White-Hawk (also seen on
other R-Car Gen3/4 systems) to this commit:

renesas_sdhi_internal_dmac ee140000.mmc: mmc0 base at
0x00000000ee140000, max clock rate 200 MHz
mmc0: new HS400 MMC card at address 0001
------------[ cut here ]------------
WARNING: CPU: 1 PID: 20 at block/blk-settings.c:202
blk_validate_limits+0x12c/0x1e0
Modules linked in:
CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted
6.8.0-rc3-white-hawk-00084-g616f87661792 #223
Hardware name: Renesas White Hawk CPU and Breakout boards based on
r8a779g0 (DT)
Workqueue: events_freezable mmc_rescan
pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : blk_validate_limits+0x12c/0x1e0
lr : blk_set_default_limits+0x14/0x1c
sp : ffffffc0829336f0
x29: ffffffc0829336f0 x28: 0000000000000000 x27: 0000000000000000
Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached
PHY driver (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=30)
x26: ffffff8443afd808 x25: ffffffc0825bd000 x24: ffffffc082933878
x23: 00000000ffffffff x22: ffffffc08147b258 x21: ffffff8443ab0c10
x20: 000000000000001a x19: ffffff8443b00000 x18: 0000000043789380
x17: ffffffc0806b2ea8 x16: ffffffc0803ab8b4 x15: ffffffc0803ab444
x14: ffffffc08039c26c x13: ffffffc080506854 x12: ffffffc080506700
x11: ffffffc08050669c x10: ffffffc080506478 x9 : ffffffc0803ad1a0
x8 : ffffff8443019120 x7 : ffffffc0803ad1a0 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000a00 x3 : 0000000000000fff
x2 : 0000000000000200 x1 : 0000000000010000 x0 : ffffffc082933878
Call trace:
blk_validate_limits+0x12c/0x1e0
blk_alloc_queue+0x7c/0x244
blk_mq_alloc_queue+0x4c/0xac
__blk_mq_alloc_disk+0x1c/0xc0
mmc_alloc_disk+0x134/0x2b4
mmc_init_queue+0x114/0x12c
mmc_blk_alloc_req+0xf0/0x34c
mmc_blk_probe+0x230/0x5b8
mmc_bus_probe+0x18/0x20
really_probe+0x138/0x270
__driver_probe_device+0xec/0x104
driver_probe_device+0x4c/0xf8
__device_attach_driver+0xa8/0xc8
bus_for_each_drv+0xa4/0xc8
__device_attach+0xe4/0x144
device_initial_probe+0x10/0x18
bus_probe_device+0x38/0xa0
device_add+0x520/0x654
mmc_add_card+0x12c/0x28c
mmc_attach_mmc+0xb8/0x154
mmc_rescan+0x208/0x250
process_scheduled_works+0x2b8/0x41c
worker_thread+0x1cc/0x24c
kthread+0xd8/0xe8
ret_from_fork+0x10/0x20
irq event stamp: 434
hardirqs last enabled at (433): [<ffffffc0808e0ac0>]
_raw_spin_unlock_irq+0x2c/0x40
hardirqs last disabled at (434): [<ffffffc0808dae28>] __schedule+0x1cc/0x84c
softirqs last enabled at (192): [<ffffffc080010300>]
__do_softirq+0x1ac/0x360
softirqs last disabled at (185): [<ffffffc08001550c>]
____do_softirq+0xc/0x14
---[ end trace 0000000000000000 ]---
mmcblk: probe of mmc0:0001 failed with error -22

Reverting this commit fixes the issue.

> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -174,8 +174,8 @@ static struct scatterlist *mmc_alloc_sg(unsigned short sg_len, gfp_t gfp)
> return sg;
> }
>
> -static void mmc_queue_setup_discard(struct request_queue *q,
> - struct mmc_card *card)
> +static void mmc_queue_setup_discard(struct mmc_card *card,
> + struct queue_limits *lim)
> {
> unsigned max_discard;
>
> @@ -183,15 +183,17 @@ static void mmc_queue_setup_discard(struct request_queue *q,
> if (!max_discard)
> return;
>
> - blk_queue_max_discard_sectors(q, max_discard);
> - q->limits.discard_granularity = card->pref_erase << 9;
> - /* granularity must not be greater than max. discard */
> - if (card->pref_erase > max_discard)
> - q->limits.discard_granularity = SECTOR_SIZE;
> + lim->max_hw_discard_sectors = max_discard;
> if (mmc_can_secure_erase_trim(card))
> - blk_queue_max_secure_erase_sectors(q, max_discard);
> + lim->max_secure_erase_sectors = max_discard;
> if (mmc_can_trim(card) && card->erased_byte == 0)
> - blk_queue_max_write_zeroes_sectors(q, max_discard);
> + lim->max_write_zeroes_sectors = max_discard;
> +
> + /* granularity must not be greater than max. discard */
> + if (card->pref_erase > max_discard)
> + lim->discard_granularity = SECTOR_SIZE;
> + else
> + lim->discard_granularity = card->pref_erase << 9;
> }
>
> static unsigned short mmc_get_max_segments(struct mmc_host *host)
> @@ -341,40 +343,53 @@ static const struct blk_mq_ops mmc_mq_ops = {
> .timeout = mmc_mq_timed_out,
> };
>
> -static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
> +static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq,
> + struct mmc_card *card)
> {
> struct mmc_host *host = card->host;
> - unsigned block_size = 512;
> + struct queue_limits lim = { };
> + struct gendisk *disk;
>
> - blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
> - blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
> if (mmc_can_erase(card))
> - mmc_queue_setup_discard(mq->queue, card);
> + mmc_queue_setup_discard(card, &lim);
>
> if (!mmc_dev(host)->dma_mask || !*mmc_dev(host)->dma_mask)
> - blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
> - blk_queue_max_hw_sectors(mq->queue,
> - min(host->max_blk_count, host->max_req_size / 512));
> - if (host->can_dma_map_merge)
> - WARN(!blk_queue_can_use_dma_map_merging(mq->queue,
> - mmc_dev(host)),
> - "merging was advertised but not possible");
> - blk_queue_max_segments(mq->queue, mmc_get_max_segments(host));
> -
> - if (mmc_card_mmc(card) && card->ext_csd.data_sector_size) {
> - block_size = card->ext_csd.data_sector_size;
> - WARN_ON(block_size != 512 && block_size != 4096);
> - }
> + lim.bounce = BLK_BOUNCE_HIGH;
> +
> + lim.max_hw_sectors = min(host->max_blk_count, host->max_req_size / 512);
> +
> + if (mmc_card_mmc(card) && card->ext_csd.data_sector_size)
> + lim.logical_block_size = card->ext_csd.data_sector_size;
> + else
> + lim.logical_block_size = 512;
> +
> + WARN_ON_ONCE(lim.logical_block_size != 512 &&
> + lim.logical_block_size != 4096);
>
> - blk_queue_logical_block_size(mq->queue, block_size);
> /*
> - * After blk_queue_can_use_dma_map_merging() was called with succeed,
> - * since it calls blk_queue_virt_boundary(), the mmc should not call
> - * both blk_queue_max_segment_size().
> + * Setting a virt_boundary implicity sets a max_segment_size, so try
> + * to set the hardware one here.
> */
> - if (!host->can_dma_map_merge)
> - blk_queue_max_segment_size(mq->queue,
> - round_down(host->max_seg_size, block_size));
> + if (host->can_dma_map_merge) {
> + lim.virt_boundary_mask = dma_get_merge_boundary(mmc_dev(host));
> + lim.max_segments = MMC_DMA_MAP_MERGE_SEGMENTS;
> + } else {
> + lim.max_segment_size =
> + round_down(host->max_seg_size, lim.logical_block_size);
> + lim.max_segments = host->max_segs;
> + }
> +
> + disk = blk_mq_alloc_disk(&mq->tag_set, &lim, mq);
> + if (IS_ERR(disk))
> + return disk;
> + mq->queue = disk->queue;
> +
> + if (mmc_host_is_spi(host) && host->use_spi_crc)
> + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, mq->queue);
> + blk_queue_rq_timeout(mq->queue, 60 * HZ);
> +
> + blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
> + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
>
> dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
>
> @@ -386,6 +401,7 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
> init_waitqueue_head(&mq->wait);
>
> mmc_crypto_setup_queue(mq->queue, host);
> + return disk;
> }
>
> static inline bool mmc_merge_capable(struct mmc_host *host)
> @@ -447,18 +463,9 @@ struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
> return ERR_PTR(ret);
>
>
> - disk = blk_mq_alloc_disk(&mq->tag_set, NULL, mq);
> - if (IS_ERR(disk)) {
> + disk = mmc_alloc_disk(mq, card);
> + if (IS_ERR(disk))
> blk_mq_free_tag_set(&mq->tag_set);
> - return disk;
> - }
> - mq->queue = disk->queue;
> -
> - if (mmc_host_is_spi(host) && host->use_spi_crc)
> - blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, mq->queue);
> - blk_queue_rq_timeout(mq->queue, 60 * HZ);
> -
> - mmc_setup_queue(mq, card);
> return disk;
> }
>
> --
> 2.39.2
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/

--
Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds