From 00be43a74ca262267ceb96c0c5e3f51d3a56342e Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 13 Jun 2022 11:42:01 +0800 Subject: [PATCH] net: axienet: make the 64b addresable DMA depends on 64b archectures Currently it is not safe to config the IP as 64-bit addressable on 32-bit archectures, which cannot perform a double-word store on its descriptor pointers. The pointer is 64-bit wide if the IP is configured as 64-bit, and the device would process the partially updated pointer on some states if the pointer was updated via two store-words. To prevent such condition, we force a probe fail if we discover that the IP has 64-bit capability but it is not running on a 64-Bit kernel. This is a series of patch (1/2). The next patch must be applied in order to make 64b DMA safe on 64b archectures. Signed-off-by: Andy Chiu Reported-by: Max Hsu Reviewed-by: Greentime Hu Signed-off-by: David S. Miller --- drivers/net/ethernet/xilinx/xilinx_axienet.h | 36 +++++++++++++++++++ .../net/ethernet/xilinx/xilinx_axienet_main.c | 28 +++------------ 2 files changed, 40 insertions(+), 24 deletions(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h index 4225efbeda3d..6c95676ba172 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet.h +++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h @@ -547,6 +547,42 @@ static inline void axienet_iow(struct axienet_local *lp, off_t offset, iowrite32(value, lp->regs + offset); } +/** + * axienet_dma_out32 - Memory mapped Axi DMA register write. + * @lp: Pointer to axienet local structure + * @reg: Address offset from the base address of the Axi DMA core + * @value: Value to be written into the Axi DMA register + * + * This function writes the desired value into the corresponding Axi DMA + * register. + */ + +static inline void axienet_dma_out32(struct axienet_local *lp, + off_t reg, u32 value) +{ + iowrite32(value, lp->dma_regs + reg); +} + +#ifdef CONFIG_64BIT +static void axienet_dma_out_addr(struct axienet_local *lp, off_t reg, + dma_addr_t addr) +{ + axienet_dma_out32(lp, reg, lower_32_bits(addr)); + + if (lp->features & XAE_FEATURE_DMA_64BIT) + axienet_dma_out32(lp, reg + 4, upper_32_bits(addr)); +} + +#else /* CONFIG_64BIT */ + +static void axienet_dma_out_addr(struct axienet_local *lp, off_t reg, + dma_addr_t addr) +{ + axienet_dma_out32(lp, reg, lower_32_bits(addr)); +} + +#endif /* CONFIG_64BIT */ + /* Function prototypes visible in xilinx_axienet_mdio.c for other files */ int axienet_mdio_enable(struct axienet_local *lp); void axienet_mdio_disable(struct axienet_local *lp); diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 93c9f305bba4..fa7bcd2c1892 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -133,30 +133,6 @@ static inline u32 axienet_dma_in32(struct axienet_local *lp, off_t reg) return ioread32(lp->dma_regs + reg); } -/** - * axienet_dma_out32 - Memory mapped Axi DMA register write. - * @lp: Pointer to axienet local structure - * @reg: Address offset from the base address of the Axi DMA core - * @value: Value to be written into the Axi DMA register - * - * This function writes the desired value into the corresponding Axi DMA - * register. - */ -static inline void axienet_dma_out32(struct axienet_local *lp, - off_t reg, u32 value) -{ - iowrite32(value, lp->dma_regs + reg); -} - -static void axienet_dma_out_addr(struct axienet_local *lp, off_t reg, - dma_addr_t addr) -{ - axienet_dma_out32(lp, reg, lower_32_bits(addr)); - - if (lp->features & XAE_FEATURE_DMA_64BIT) - axienet_dma_out32(lp, reg + 4, upper_32_bits(addr)); -} - static void desc_set_phys_addr(struct axienet_local *lp, dma_addr_t addr, struct axidma_bd *desc) { @@ -2061,6 +2037,10 @@ static int axienet_probe(struct platform_device *pdev) iowrite32(0x0, desc); } } + if (!IS_ENABLED(CONFIG_64BIT) && lp->features & XAE_FEATURE_DMA_64BIT) { + dev_err(&pdev->dev, "64-bit addressable DMA is not compatible with 32-bit archecture\n"); + goto cleanup_clk; + } ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(addr_width)); if (ret) {