[RFC PATCH v1 25/57] net: marvell: Remove PAGE_SIZE compile-time constant assumption

Ryan Roberts
2024-10-14T11:59:09Z

To prepare for supporting boot-time page size selection, refactor code
to remove assumptions about PAGE_SIZE being compile-time constant. Code
intended to be equivalent when compile-time page size is active.

Updated sky2 "struct rx_ring_info" member frag_addr[] to contain enough
entries for the smallest supported page size.

Updated mvneta "struct mvneta_tx_queue" members tso_hdrs[] and
tso_hdrs_phys[] to contain enough entries for the smallest supported
page size.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---

***NOTE***
Any confused maintainers may want to read the cover note here for context:
https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/

drivers/net/ethernet/marvell/mvneta.c | 9 ++++++---
drivers/net/ethernet/marvell/sky2.h | 2 +-
2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 41894834fb53c..f3ac371d8f3a7 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -346,12 +346,15 @@

/* The size of a TSO header page */
#define MVNETA_TSO_PAGE_SIZE (2 * PAGE_SIZE)
+#define MVNETA_TSO_PAGE_SIZE_MIN (2 * PAGE_SIZE_MIN)

/* Number of TSO headers per page. This should be a power of 2 */
#define MVNETA_TSO_PER_PAGE (MVNETA_TSO_PAGE_SIZE / TSO_HEADER_SIZE)
+#define MVNETA_TSO_PER_PAGE_MIN (MVNETA_TSO_PAGE_SIZE_MIN / TSO_HEADER_SIZE)

/* Maximum number of TSO header pages */
#define MVNETA_MAX_TSO_PAGES (MVNETA_MAX_TXD / MVNETA_TSO_PER_PAGE)
+#define MVNETA_MAX_TSO_PAGES_MAX (MVNETA_MAX_TXD / MVNETA_TSO_PER_PAGE_MIN)

/* descriptor aligned size */
#define MVNETA_DESC_ALIGNED_SIZE 32
@@ -696,10 +699,10 @@ struct mvneta_tx_queue {
int next_desc_to_proc;

/* DMA buffers for TSO headers */
- char *tso_hdrs[MVNETA_MAX_TSO_PAGES];
+ char *tso_hdrs[MVNETA_MAX_TSO_PAGES_MAX];

/* DMA address of TSO headers */
- dma_addr_t tso_hdrs_phys[MVNETA_MAX_TSO_PAGES];
+ dma_addr_t tso_hdrs_phys[MVNETA_MAX_TSO_PAGES_MAX];

/* Affinity mask for CPUs*/
cpumask_t affinity_mask;
@@ -5895,7 +5898,7 @@ static int __init mvneta_driver_init(void)
{
int ret;

- BUILD_BUG_ON_NOT_POWER_OF_2(MVNETA_TSO_PER_PAGE);
+ BUILD_BUG_ON_NOT_POWER_OF_2(MVNETA_TSO_PER_PAGE_MIN);

ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "net/mvneta:online",
mvneta_cpu_online,
diff --git a/drivers/net/ethernet/marvell/sky2.h b/drivers/net/ethernet/marvell/sky2.h
index 8d0bacf4e49cc..8ee73ae087dfc 100644
--- a/drivers/net/ethernet/marvell/sky2.h
+++ b/drivers/net/ethernet/marvell/sky2.h
@@ -2195,7 +2195,7 @@ struct rx_ring_info {
struct sk_buff *skb;
dma_addr_t data_addr;
DEFINE_DMA_UNMAP_LEN(data_size);
- dma_addr_t frag_addr[ETH_JUMBO_MTU >> PAGE_SHIFT ?: 1];
+ dma_addr_t frag_addr[ETH_JUMBO_MTU >> PAGE_SHIFT_MIN ?: 1];
};

enum flow_control {
--
2.43.0