diff mbox series

[net-next,04/12] net: lan966x: use the FDMA library for allocation of rx buffers

Message ID 20240905-fdma-lan966x-v1-4-e083f8620165@microchip.com (mailing list archive)
State Accepted
Commit 01a70754327bd628610587b6b7ae5efe2a5e7d1c
Delegated to: Netdev Maintainers
Headers show
Series net: lan966x: use the newly introduced FDMA library | expand

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netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 16 this patch: 16
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netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 280 lines checked
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netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-09-07--06-00 (tests: 722)

Commit Message

Daniel Machon Sept. 5, 2024, 8:06 a.m. UTC 
Use the two functions: fdma_alloc_phys() and fdma_dcb_init() for rx
buffer allocation and use the new buffers throughout.

In order to replace the old buffers with the new ones, we have to do the
following refactoring:

    - use fdma_alloc_phys() and fdma_dcb_init()

    - replace the variables: rx->dma, rx->dcbs and rx->last_entry
      with the equivalents from the FDMA struct.

    - make use of fdma->db_size for rx buffer size.

    - add lan966x_fdma_rx_dataptr_cb callback for obtaining the dataptr.

    - Initialize FDMA struct values.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../net/ethernet/microchip/lan966x/lan966x_fdma.c  | 116 ++++++++++-----------
 .../net/ethernet/microchip/lan966x/lan966x_main.h  |  15 ---
 2 files changed, 55 insertions(+), 76 deletions(-)

Comments

Paolo Abeni Sept. 10, 2024, 9:15 a.m. UTC | #1 
On 9/5/24 10:06, Daniel Machon wrote:
> Use the two functions: fdma_alloc_phys() and fdma_dcb_init() for rx
> buffer allocation and use the new buffers throughout.
> 
> In order to replace the old buffers with the new ones, we have to do the
> following refactoring:
> 
>      - use fdma_alloc_phys() and fdma_dcb_init()
> 
>      - replace the variables: rx->dma, rx->dcbs and rx->last_entry
>        with the equivalents from the FDMA struct.
> 
>      - make use of fdma->db_size for rx buffer size.
> 
>      - add lan966x_fdma_rx_dataptr_cb callback for obtaining the dataptr.
> 
>      - Initialize FDMA struct values.
> 
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> ---
>   .../net/ethernet/microchip/lan966x/lan966x_fdma.c  | 116 ++++++++++-----------
>   .../net/ethernet/microchip/lan966x/lan966x_main.h  |  15 ---
>   2 files changed, 55 insertions(+), 76 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> index b64f04ff99a8..99d09c97737e 100644
> --- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> @@ -6,13 +6,30 @@
>   
>   #include "lan966x_main.h"
>   
> +static int lan966x_fdma_rx_dataptr_cb(struct fdma *fdma, int dcb, int db,
> +				      u64 *dataptr)
> +{
> +	struct lan966x *lan966x = (struct lan966x *)fdma->priv;
> +	struct lan966x_rx *rx = &lan966x->rx;
> +	struct page *page;
> +
> +	page = page_pool_dev_alloc_pages(rx->page_pool);
> +	if (unlikely(!page))
> +		return -ENOMEM;
> +
> +	rx->page[dcb][db] = page;
> +	*dataptr = page_pool_get_dma_addr(page) + XDP_PACKET_HEADROOM;
> +
> +	return 0;
> +}

Very nice cleanup indeed!

Out of ENOMEM I can't recall if the following was already discussed, but 
looking at this cb, I'm wondering if a possible follow-up could replace 
the dataptr_cb() and nextptr_cb() with lib functions i.e. operating on 
page pool or doing netdev allocations according to some fdma lib flags.

Cheers,

Paolo
Daniel Machon Sept. 10, 2024, 9:42 a.m. UTC | #2 
> Use the two functions: fdma_alloc_phys() and fdma_dcb_init() for rx
> > buffer allocation and use the new buffers throughout.
> > 
> > In order to replace the old buffers with the new ones, we have to do the
> > following refactoring:
> > 
> >      - use fdma_alloc_phys() and fdma_dcb_init()
> > 
> >      - replace the variables: rx->dma, rx->dcbs and rx->last_entry
> >        with the equivalents from the FDMA struct.
> > 
> >      - make use of fdma->db_size for rx buffer size.
> > 
> >      - add lan966x_fdma_rx_dataptr_cb callback for obtaining the dataptr.
> > 
> >      - Initialize FDMA struct values.
> > 
> > Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
> > Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> >   .../net/ethernet/microchip/lan966x/lan966x_fdma.c  | 116 ++++++++++-----------
> >   .../net/ethernet/microchip/lan966x/lan966x_main.h  |  15 ---
> >   2 files changed, 55 insertions(+), 76 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> > index b64f04ff99a8..99d09c97737e 100644
> > --- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> > +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> > @@ -6,13 +6,30 @@
> > 
> >   #include "lan966x_main.h"
> > 
> > +static int lan966x_fdma_rx_dataptr_cb(struct fdma *fdma, int dcb, int db,
> > +                                   u64 *dataptr)
> > +{
> > +     struct lan966x *lan966x = (struct lan966x *)fdma->priv;
> > +     struct lan966x_rx *rx = &lan966x->rx;
> > +     struct page *page;
> > +
> > +     page = page_pool_dev_alloc_pages(rx->page_pool);
> > +     if (unlikely(!page))
> > +             return -ENOMEM;
> > +
> > +     rx->page[dcb][db] = page;
> > +     *dataptr = page_pool_get_dma_addr(page) + XDP_PACKET_HEADROOM;
> > +
> > +     return 0;
> > +}
> 
> Very nice cleanup indeed!
> 
> Out of ENOMEM I can't recall if the following was already discussed, but
> looking at this cb, I'm wondering if a possible follow-up could replace
> the dataptr_cb() and nextptr_cb() with lib functions i.e. operating on
> page pool or doing netdev allocations according to some fdma lib flags.
> 
> Cheers,
> 
> Paolo
>

Hi Paolo,

Something like this could definitely be added down the road. I initially
left this out to reduce library complexity.

Thanks for reviewing!

/Daniel
diff mbox series

Patch

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index b64f04ff99a8..99d09c97737e 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -6,13 +6,30 @@ 
 
 #include "lan966x_main.h"
 
+static int lan966x_fdma_rx_dataptr_cb(struct fdma *fdma, int dcb, int db,
+				      u64 *dataptr)
+{
+	struct lan966x *lan966x = (struct lan966x *)fdma->priv;
+	struct lan966x_rx *rx = &lan966x->rx;
+	struct page *page;
+
+	page = page_pool_dev_alloc_pages(rx->page_pool);
+	if (unlikely(!page))
+		return -ENOMEM;
+
+	rx->page[dcb][db] = page;
+	*dataptr = page_pool_get_dma_addr(page) + XDP_PACKET_HEADROOM;
+
+	return 0;
+}
+
 static int lan966x_fdma_channel_active(struct lan966x *lan966x)
 {
 	return lan_rd(lan966x, FDMA_CH_ACTIVE);
 }
 
 static struct page *lan966x_fdma_rx_alloc_page(struct lan966x_rx *rx,
-					       struct lan966x_db *db)
+					       struct fdma_db *db)
 {
 	struct page *page;
 
@@ -50,11 +67,11 @@  static void lan966x_fdma_rx_free_page(struct lan966x_rx *rx)
 }
 
 static void lan966x_fdma_rx_add_dcb(struct lan966x_rx *rx,
-				    struct lan966x_rx_dcb *dcb,
+				    struct fdma_dcb *dcb,
 				    u64 nextptr)
 {
 	struct fdma *fdma = &rx->fdma;
-	struct lan966x_db *db;
+	struct fdma_db *db;
 	int i;
 
 	for (i = 0; i < fdma->n_dbs; ++i) {
@@ -65,8 +82,8 @@  static void lan966x_fdma_rx_add_dcb(struct lan966x_rx *rx,
 	dcb->nextptr = FDMA_DCB_INVALID_DATA;
 	dcb->info = FDMA_DCB_INFO_DATAL(PAGE_SIZE << rx->page_order);
 
-	rx->last_entry->nextptr = nextptr;
-	rx->last_entry = dcb;
+	fdma->last_dcb->nextptr = nextptr;
+	fdma->last_dcb = dcb;
 }
 
 static int lan966x_fdma_rx_alloc_page_pool(struct lan966x_rx *rx)
@@ -108,45 +125,17 @@  static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
 {
 	struct lan966x *lan966x = rx->lan966x;
 	struct fdma *fdma = &rx->fdma;
-	struct lan966x_rx_dcb *dcb;
-	struct lan966x_db *db;
-	struct page *page;
-	int i, j;
-	int size;
+	int err;
 
 	if (lan966x_fdma_rx_alloc_page_pool(rx))
 		return PTR_ERR(rx->page_pool);
 
-	/* calculate how many pages are needed to allocate the dcbs */
-	size = sizeof(struct lan966x_rx_dcb) * fdma->n_dcbs;
-	size = ALIGN(size, PAGE_SIZE);
-
-	rx->dcbs = dma_alloc_coherent(lan966x->dev, size, &rx->dma, GFP_KERNEL);
-	if (!rx->dcbs)
-		return -ENOMEM;
-
-	rx->last_entry = rx->dcbs;
-	fdma->db_index = 0;
-	fdma->dcb_index = 0;
-
-	/* Now for each dcb allocate the dbs */
-	for (i = 0; i < fdma->n_dcbs; ++i) {
-		dcb = &rx->dcbs[i];
-		dcb->info = 0;
-
-		/* For each db allocate a page and map it to the DB dataptr. */
-		for (j = 0; j < fdma->n_dbs; ++j) {
-			db = &dcb->db[j];
-			page = lan966x_fdma_rx_alloc_page(rx, db);
-			if (!page)
-				return -ENOMEM;
-
-			db->status = 0;
-			rx->page[i][j] = page;
-		}
+	err = fdma_alloc_coherent(lan966x->dev, fdma);
+	if (err)
+		return err;
 
-		lan966x_fdma_rx_add_dcb(rx, dcb, rx->dma + sizeof(*dcb) * i);
-	}
+	fdma_dcbs_init(fdma, FDMA_DCB_INFO_DATAL(fdma->db_size),
+		       FDMA_DCB_STATUS_INTR);
 
 	return 0;
 }
@@ -168,7 +157,7 @@  static void lan966x_fdma_rx_free(struct lan966x_rx *rx)
 	/* Now it is possible to do the cleanup of dcb */
 	size = sizeof(struct lan966x_tx_dcb) * fdma->n_dcbs;
 	size = ALIGN(size, PAGE_SIZE);
-	dma_free_coherent(lan966x->dev, size, rx->dcbs, rx->dma);
+	dma_free_coherent(lan966x->dev, size, fdma->dcbs, fdma->dma);
 }
 
 static void lan966x_fdma_rx_start(struct lan966x_rx *rx)
@@ -180,9 +169,9 @@  static void lan966x_fdma_rx_start(struct lan966x_rx *rx)
 	/* When activating a channel, first is required to write the first DCB
 	 * address and then to activate it
 	 */
-	lan_wr(lower_32_bits((u64)rx->dma), lan966x,
+	lan_wr(lower_32_bits((u64)fdma->dma), lan966x,
 	       FDMA_DCB_LLP(fdma->channel_id));
-	lan_wr(upper_32_bits((u64)rx->dma), lan966x,
+	lan_wr(upper_32_bits((u64)fdma->dma), lan966x,
 	       FDMA_DCB_LLP1(fdma->channel_id));
 
 	lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(fdma->n_dbs) |
@@ -297,7 +286,7 @@  static void lan966x_fdma_tx_free(struct lan966x_tx *tx)
 
 	size = sizeof(struct lan966x_tx_dcb) * fdma->n_dcbs;
 	size = ALIGN(size, PAGE_SIZE);
-	dma_free_coherent(lan966x->dev, size, tx->dcbs, tx->dma);
+	dma_free_coherent(lan966x->dev, size, fdma->dcbs, fdma->dma);
 }
 
 static void lan966x_fdma_tx_activate(struct lan966x_tx *tx)
@@ -465,10 +454,10 @@  static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
 static bool lan966x_fdma_rx_more_frames(struct lan966x_rx *rx)
 {
 	struct fdma *fdma = &rx->fdma;
-	struct lan966x_db *db;
+	struct fdma_db *db;
 
 	/* Check if there is any data */
-	db = &rx->dcbs[fdma->dcb_index].db[fdma->db_index];
+	db = &fdma->dcbs[fdma->dcb_index].db[fdma->db_index];
 	if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
 		return false;
 
@@ -480,10 +469,10 @@  static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
 	struct lan966x *lan966x = rx->lan966x;
 	struct fdma *fdma = &rx->fdma;
 	struct lan966x_port *port;
-	struct lan966x_db *db;
+	struct fdma_db *db;
 	struct page *page;
 
-	db = &rx->dcbs[fdma->dcb_index].db[fdma->db_index];
+	db = &fdma->dcbs[fdma->dcb_index].db[fdma->db_index];
 	page = rx->page[fdma->dcb_index][fdma->db_index];
 	if (unlikely(!page))
 		return FDMA_ERROR;
@@ -510,16 +499,16 @@  static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
 {
 	struct lan966x *lan966x = rx->lan966x;
 	struct fdma *fdma = &rx->fdma;
-	struct lan966x_db *db;
 	struct sk_buff *skb;
+	struct fdma_db *db;
 	struct page *page;
 	u64 timestamp;
 
 	/* Get the received frame and unmap it */
-	db = &rx->dcbs[fdma->dcb_index].db[fdma->db_index];
+	db = &fdma->dcbs[fdma->dcb_index].db[fdma->db_index];
 	page = rx->page[fdma->dcb_index][fdma->db_index];
 
-	skb = build_skb(page_address(page), PAGE_SIZE << rx->page_order);
+	skb = build_skb(page_address(page), fdma->db_size);
 	if (unlikely(!skb))
 		goto free_page;
 
@@ -562,12 +551,12 @@  static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
 {
 	struct lan966x *lan966x = container_of(napi, struct lan966x, napi);
 	struct lan966x_rx *rx = &lan966x->rx;
-	struct lan966x_rx_dcb *old_dcb;
 	struct fdma *fdma = &rx->fdma;
 	int dcb_reload, counter = 0;
-	struct lan966x_db *db;
+	struct fdma_dcb *old_dcb;
 	bool redirect = false;
 	struct sk_buff *skb;
+	struct fdma_db *db;
 	struct page *page;
 	u64 src_port;
 	u64 nextptr;
@@ -613,18 +602,18 @@  static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
 allocate_new:
 	/* Allocate new pages and map them */
 	while (dcb_reload != fdma->dcb_index) {
-		db = &rx->dcbs[dcb_reload].db[fdma->db_index];
+		db = &fdma->dcbs[dcb_reload].db[fdma->db_index];
 		page = lan966x_fdma_rx_alloc_page(rx, db);
 		if (unlikely(!page))
 			break;
 		rx->page[dcb_reload][fdma->db_index] = page;
 
-		old_dcb = &rx->dcbs[dcb_reload];
+		old_dcb = &fdma->dcbs[dcb_reload];
 		dcb_reload++;
 		dcb_reload &= fdma->n_dcbs - 1;
 
-		nextptr = rx->dma + ((unsigned long)old_dcb -
-				     (unsigned long)rx->dcbs);
+		nextptr = fdma->dma + ((unsigned long)old_dcb -
+				     (unsigned long)fdma->dcbs);
 		lan966x_fdma_rx_add_dcb(rx, old_dcb, nextptr);
 		lan966x_fdma_rx_reload(rx);
 	}
@@ -933,8 +922,8 @@  static int lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu)
 	int err;
 
 	/* Store these for later to free them */
-	rx_dma = lan966x->rx.dma;
-	rx_dcbs = lan966x->rx.dcbs;
+	rx_dma = lan966x->rx.fdma.dma;
+	rx_dcbs = lan966x->rx.fdma.dcbs;
 	page_pool = lan966x->rx.page_pool;
 
 	napi_synchronize(&lan966x->napi);
@@ -950,7 +939,7 @@  static int lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu)
 		goto restore;
 	lan966x_fdma_rx_start(&lan966x->rx);
 
-	size = sizeof(struct lan966x_rx_dcb) * lan966x->rx.fdma.n_dcbs;
+	size = sizeof(struct fdma_dcb) * lan966x->rx.fdma.n_dcbs;
 	size = ALIGN(size, PAGE_SIZE);
 	dma_free_coherent(lan966x->dev, size, rx_dcbs, rx_dma);
 
@@ -962,8 +951,8 @@  static int lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu)
 	return err;
 restore:
 	lan966x->rx.page_pool = page_pool;
-	lan966x->rx.dma = rx_dma;
-	lan966x->rx.dcbs = rx_dcbs;
+	lan966x->rx.fdma.dma = rx_dma;
+	lan966x->rx.fdma.dcbs = rx_dcbs;
 	lan966x_fdma_rx_start(&lan966x->rx);
 
 	return err;
@@ -1056,6 +1045,11 @@  int lan966x_fdma_init(struct lan966x *lan966x)
 	lan966x->rx.fdma.channel_id = FDMA_XTR_CHANNEL;
 	lan966x->rx.fdma.n_dcbs = FDMA_DCB_MAX;
 	lan966x->rx.fdma.n_dbs = FDMA_RX_DCB_MAX_DBS;
+	lan966x->rx.fdma.priv = lan966x;
+	lan966x->rx.fdma.size = fdma_get_size(&lan966x->rx.fdma);
+	lan966x->rx.fdma.db_size = PAGE_SIZE << lan966x->rx.page_order;
+	lan966x->rx.fdma.ops.nextptr_cb = &fdma_nextptr_cb;
+	lan966x->rx.fdma.ops.dataptr_cb = &lan966x_fdma_rx_dataptr_cb;
 	lan966x->rx.max_mtu = lan966x_fdma_get_max_frame(lan966x);
 	lan966x->tx.lan966x = lan966x;
 	lan966x->tx.fdma.channel_id = FDMA_INJ_CHANNEL;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index fb9d8e00fe69..8edb5ea484ee 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -196,12 +196,6 @@  struct lan966x_db {
 	u64 status;
 };
 
-struct lan966x_rx_dcb {
-	u64 nextptr;
-	u64 info;
-	struct lan966x_db db[FDMA_RX_DCB_MAX_DBS];
-};
-
 struct lan966x_tx_dcb {
 	u64 nextptr;
 	u64 info;
@@ -213,18 +207,9 @@  struct lan966x_rx {
 
 	struct fdma fdma;
 
-	/* Pointer to the array of hardware dcbs. */
-	struct lan966x_rx_dcb *dcbs;
-
-	/* Pointer to the last address in the dcbs. */
-	struct lan966x_rx_dcb *last_entry;
-
 	/* For each DB, there is a page */
 	struct page *page[FDMA_DCB_MAX][FDMA_RX_DCB_MAX_DBS];
 
-	/* Represents the dma address to the dcbs array */
-	dma_addr_t dma;
-
 	/* Represents the page order that is used to allocate the pages for the
 	 * RX buffers. This value is calculated based on max MTU of the devices.
 	 */