[PATCH 20/38] net: ethernet: sgi: ioc3-eth: apply the DMA attributes only to 64-bit addresses
flat view
WARM1d
From: Imre Kaloz <kaloz@kernel.org>
Date: 2026-10-01 16:13:59
Also in:
linux-mips, lkml
Subsystem:
ioc3 ethernet driver, networking drivers, the rest · Maintainers:
Thomas Bogendoerfer, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
A Bridge 64-bit direct-mapped DMA address carries the target widget and the DMA attributes. An address in a bridge's 2GB 32-bit direct window carries neither, so attributes OR-ed onto one form a 64-bit address aimed at widget 0, and every receive raises a PCI error. Apply the attributes, and the RX barrier's upper address bits, only to 64-bit addresses, in preparation for driving an XBridge through its 32-bit window. Signed-off-by: Imre Kaloz <kaloz@kernel.org> --- drivers/net/ethernet/sgi/ioc3-eth.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/sgi/ioc3-eth.c
index 009f37105eaf..8702dfdf4c36 100644
--- a/drivers/net/ethernet/sgi/ioc3-eth.c
+++ b/drivers/net/ethernet/sgi/ioc3-eth.c@@ -152,19 +152,37 @@ static inline int ioc3_alloc_skb(struct ioc3_private *ip, struct sk_buff **skb, } #ifdef CONFIG_PCI_XTALK_BRIDGE +/* A Bridge 64-bit direct-mapped DMA address carries the target widget in + * bits 63:60 and the DMA attributes below it. An XBridge is driven through + * its 32-bit direct window instead, where an address carries neither, so + * attributes OR-ed onto one form a 64-bit address aimed at widget 0. + */ static inline unsigned long ioc3_map(dma_addr_t addr, unsigned long attr) { + if (!(addr & PCI64_ATTR_TARG_MASK)) + return addr; + return (addr & ~PCI64_ATTR_BAR) | attr; } -#define ERBAR_VAL (ERBAR_BARRIER_BIT << ERBAR_RXBARR_SHIFT) +/* The RX barrier's upper address bits follow the same form. */ +static inline u32 ioc3_erbar(dma_addr_t addr) +{ + if (!(addr & PCI64_ATTR_TARG_MASK)) + return 0; + + return ERBAR_BARRIER_BIT << ERBAR_RXBARR_SHIFT; +} #else static inline unsigned long ioc3_map(dma_addr_t addr, unsigned long attr) { return addr; } -#define ERBAR_VAL 0 +static inline u32 ioc3_erbar(dma_addr_t addr) +{ + return 0; +} #endif static int ioc3eth_nvmem_match(struct device *dev, const void *data)
@@ -727,7 +745,7 @@ static void ioc3_init(struct net_device *dev) readl(®s->emcr); /* Misc registers */ - writel(ERBAR_VAL, ®s->erbar); + writel(ioc3_erbar(ip->rxr_dma), ®s->erbar); readl(®s->etcdc); /* Clear on read */ writel(15, ®s->ercsr); /* RX low watermark */ writel(0, ®s->ertr); /* Interrupt immediately */
--
2.47.3