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Message-ID: <b5b4b96f-e512-4c1a-b749-f9fc3e7c2fcf@linux.ibm.com>
Date: Fri, 16 Feb 2024 15:13:23 +0100
From: Wenjia Zhang <wenjia@...ux.ibm.com>
To: Wen Gu <guwen@...ux.alibaba.com>, wintera@...ux.ibm.com, hca@...ux.ibm.com,
gor@...ux.ibm.com, agordeev@...ux.ibm.com, davem@...emloft.net,
edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
jaka@...ux.ibm.com, Gerd Bayer <gbayer@...ux.ibm.com>
Cc: borntraeger@...ux.ibm.com, svens@...ux.ibm.com, alibuda@...ux.alibaba.com,
tonylu@...ux.alibaba.com, linux-s390@...r.kernel.org,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next 06/15] net/smc: implement DMB-related operations
of loopback-ism
On 11.01.24 13:00, Wen Gu wrote:
> This implements DMB (un)registration and data move operations of
> loopback-ism device.
>
> Signed-off-by: Wen Gu <guwen@...ux.alibaba.com>
> ---
> net/smc/smc_cdc.c | 6 ++
> net/smc/smc_cdc.h | 1 +
> net/smc/smc_loopback.c | 133 ++++++++++++++++++++++++++++++++++++++++-
> net/smc/smc_loopback.h | 13 ++++
> 4 files changed, 150 insertions(+), 3 deletions(-)
>
> diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
> index 3c06625ceb20..c820ef197610 100644
> --- a/net/smc/smc_cdc.c
> +++ b/net/smc/smc_cdc.c
> @@ -410,6 +410,12 @@ static void smc_cdc_msg_recv(struct smc_sock *smc, struct smc_cdc_msg *cdc)
> static void smcd_cdc_rx_tsklet(struct tasklet_struct *t)
> {
> struct smc_connection *conn = from_tasklet(conn, t, rx_tsklet);
> +
> + smcd_cdc_rx_handler(conn);
> +}
> +
> +void smcd_cdc_rx_handler(struct smc_connection *conn)
> +{
> struct smcd_cdc_msg *data_cdc;
> struct smcd_cdc_msg cdc;
> struct smc_sock *smc;
> diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h
> index 696cc11f2303..11559d4ebf2b 100644
> --- a/net/smc/smc_cdc.h
> +++ b/net/smc/smc_cdc.h
> @@ -301,5 +301,6 @@ int smcr_cdc_msg_send_validation(struct smc_connection *conn,
> struct smc_wr_buf *wr_buf);
> int smc_cdc_init(void) __init;
> void smcd_cdc_rx_init(struct smc_connection *conn);
> +void smcd_cdc_rx_handler(struct smc_connection *conn);
>
> #endif /* SMC_CDC_H */
> diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
> index 353d4a2d69a1..f72e7b24fc1a 100644
> --- a/net/smc/smc_loopback.c
> +++ b/net/smc/smc_loopback.c
> @@ -15,11 +15,13 @@
> #include <linux/types.h>
> #include <net/smc.h>
>
> +#include "smc_cdc.h"
> #include "smc_ism.h"
> #include "smc_loopback.h"
>
> #if IS_ENABLED(CONFIG_SMC_LO)
> #define SMC_LO_V2_CAPABLE 0x1 /* loopback-ism acts as ISMv2 */
> +#define SMC_DMA_ADDR_INVALID (~(dma_addr_t)0)
>
> static const char smc_lo_dev_name[] = "loopback-ism";
> static struct smc_lo_dev *lo_dev;
> @@ -50,6 +52,97 @@ static int smc_lo_query_rgid(struct smcd_dev *smcd, struct smcd_gid *rgid,
> return 0;
> }
>
> +static int smc_lo_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb,
> + void *client_priv)
> +{
> + struct smc_lo_dmb_node *dmb_node, *tmp_node;
> + struct smc_lo_dev *ldev = smcd->priv;
> + int sba_idx, order, rc;
> + struct page *pages;
> +
> + /* check space for new dmb */
> + for_each_clear_bit(sba_idx, ldev->sba_idx_mask, SMC_LO_MAX_DMBS) {
> + if (!test_and_set_bit(sba_idx, ldev->sba_idx_mask))
> + break;
> + }
> + if (sba_idx == SMC_LO_MAX_DMBS)
> + return -ENOSPC;
> +
> + dmb_node = kzalloc(sizeof(*dmb_node), GFP_KERNEL);
> + if (!dmb_node) {
> + rc = -ENOMEM;
> + goto err_bit;
> + }
> +
> + dmb_node->sba_idx = sba_idx;
> + order = get_order(dmb->dmb_len);
> + pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
> + __GFP_NOMEMALLOC | __GFP_COMP |
> + __GFP_NORETRY | __GFP_ZERO,
> + order);
> + if (!pages) {
> + rc = -ENOMEM;
> + goto err_node;
> + }
> + dmb_node->cpu_addr = (void *)page_address(pages);
> + dmb_node->len = dmb->dmb_len;
> + dmb_node->dma_addr = SMC_DMA_ADDR_INVALID;
> +
> +again:
> + /* add new dmb into hash table */
> + get_random_bytes(&dmb_node->token, sizeof(dmb_node->token));
> + write_lock(&ldev->dmb_ht_lock);
> + hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_node->token) {
> + if (tmp_node->token == dmb_node->token) {
> + write_unlock(&ldev->dmb_ht_lock);
> + goto again;
> + }
> + }
> + hash_add(ldev->dmb_ht, &dmb_node->list, dmb_node->token);
> + write_unlock(&ldev->dmb_ht_lock);
> +
The write_lock_irqsave()/write_unlock_irqrestore() and
read_lock_irqsave()/read_unlock_irqrestore()should be used instead of
write_lock()/write_unlock() and read_lock()/read_unlock() in order to
keep the lock irq-safe.
> + dmb->sba_idx = dmb_node->sba_idx;
> + dmb->dmb_tok = dmb_node->token;
> + dmb->cpu_addr = dmb_node->cpu_addr;
> + dmb->dma_addr = dmb_node->dma_addr;
> + dmb->dmb_len = dmb_node->len;
> +
> + return 0;
> +
> +err_node:
> + kfree(dmb_node);
> +err_bit:
> + clear_bit(sba_idx, ldev->sba_idx_mask);
> + return rc;
> +}
> +
> +static int smc_lo_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
> +{
> + struct smc_lo_dmb_node *dmb_node = NULL, *tmp_node;
> + struct smc_lo_dev *ldev = smcd->priv;
> +
> + /* remove dmb from hash table */
> + write_lock(&ldev->dmb_ht_lock);
> + hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb->dmb_tok) {
> + if (tmp_node->token == dmb->dmb_tok) {
> + dmb_node = tmp_node;
> + break;
> + }
> + }
> + if (!dmb_node) {
> + write_unlock(&ldev->dmb_ht_lock);
> + return -EINVAL;
> + }
> + hash_del(&dmb_node->list);
> + write_unlock(&ldev->dmb_ht_lock);
> +
> + clear_bit(dmb_node->sba_idx, ldev->sba_idx_mask);
> + kfree(dmb_node->cpu_addr);
> + kfree(dmb_node);
> +
> + return 0;
> +}
> +
> static int smc_lo_add_vlan_id(struct smcd_dev *smcd, u64 vlan_id)
> {
> return -EOPNOTSUPP;
> @@ -76,6 +169,38 @@ static int smc_lo_signal_event(struct smcd_dev *dev, struct smcd_gid *rgid,
> return 0;
> }
>
> +static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok,
> + unsigned int idx, bool sf, unsigned int offset,
> + void *data, unsigned int size)
> +{
> + struct smc_lo_dmb_node *rmb_node = NULL, *tmp_node;
> + struct smc_lo_dev *ldev = smcd->priv;
> +
> + read_lock(&ldev->dmb_ht_lock);
> + hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_tok) {
> + if (tmp_node->token == dmb_tok) {
> + rmb_node = tmp_node;
> + break;
> + }
> + }
> + if (!rmb_node) {
> + read_unlock(&ldev->dmb_ht_lock);
> + return -EINVAL;
> + }
> + read_unlock(&ldev->dmb_ht_lock);
> +
> + memcpy((char *)rmb_node->cpu_addr + offset, data, size);
> +
Should this read_unlock be placed behind memcpy()?
<...>
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