net: lpc-enet: factor out iram access

The lpc_eth driver uses a platform specific method to find
the internal sram. This prevents building it on other machines.

Rework to only use one function call and keep the other platform
internals where they belong. Ideally this would look up the
sram location from DT, but as this is a rarely used driver,
I want to keep the modifications to a minimum.

Link: https://lore.kernel.org/r/20190809144043.476786-7-arnd@arndb.deSigned-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-lpc32xx/common.c

@@ -8,6 +8,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/soc/nxp/lpc32xx-misc.h>
 
 #include <asm/mach/map.h>
 #include <asm/system_info.h>
@@ -32,7 +33,7 @@ void lpc32xx_get_uid(u32 devid[4])
  */
 #define LPC32XX_IRAM_BANK_SIZE SZ_128K
 static u32 iram_size;
-u32 lpc32xx_return_iram_size(void)
+u32 lpc32xx_return_iram(void __iomem **mapbase, dma_addr_t *dmaaddr)
 {
 	if (iram_size == 0) {
 		u32 savedval1, savedval2;
@@ -53,10 +54,14 @@ u32 lpc32xx_return_iram_size(void)
 		} else
 			iram_size = LPC32XX_IRAM_BANK_SIZE * 2;
 	}
+	if (dmaaddr)
+		*dmaaddr = LPC32XX_IRAM_BASE;
+	if (mapbase)
+		*mapbase = io_p2v(LPC32XX_IRAM_BASE);
 
 	return iram_size;
 }
-EXPORT_SYMBOL_GPL(lpc32xx_return_iram_size);
+EXPORT_SYMBOL_GPL(lpc32xx_return_iram);
 
 static struct map_desc lpc32xx_io_desc[] __initdata = {
 	{

arch/arm/mach-lpc32xx/common.h

@@ -23,7 +23,6 @@ extern void __init lpc32xx_serial_init(void);
  */
 extern void lpc32xx_get_uid(u32 devid[4]);
 
-extern u32 lpc32xx_return_iram_size(void);
 /*
  * Pointers used for sizing and copying suspend function data
  */

arch/arm/mach-lpc32xx/include/mach/board.h

-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * arm/arch/mach-lpc32xx/include/mach/board.h
- *
- * Author: Kevin Wells <kevin.wells@nxp.com>
- *
- * Copyright (C) 2010 NXP Semiconductors
- */
-
-#ifndef __ASM_ARCH_BOARD_H
-#define __ASM_ARCH_BOARD_H
-
-extern u32 lpc32xx_return_iram_size(void);
-
-#endif  /* __ASM_ARCH_BOARD_H */

drivers/net/ethernet/nxp/lpc_eth.c

@@ -18,8 +18,8 @@
 #include <linux/phy.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
+#include <linux/soc/nxp/lpc32xx-misc.h>
 
-#include <mach/board.h>
 #include <mach/hardware.h>
 #include <mach/platform.h>
 
@@ -1311,16 +1311,15 @@ static int lpc_eth_drv_probe(struct platform_device *pdev)
 	/* Get size of DMA buffers/descriptors region */
 	pldat->dma_buff_size = (ENET_TX_DESC + ENET_RX_DESC) * (ENET_MAXF_SIZE +
 		sizeof(struct txrx_desc_t) + sizeof(struct rx_status_t));
-	pldat->dma_buff_base_v = 0;
 
 	if (use_iram_for_net(dev)) {
-		dma_handle = LPC32XX_IRAM_BASE;
-		if (pldat->dma_buff_size <= lpc32xx_return_iram_size())
-			pldat->dma_buff_base_v =
-				io_p2v(LPC32XX_IRAM_BASE);
-		else
+		if (pldat->dma_buff_size >
+		    lpc32xx_return_iram(&pldat->dma_buff_base_v, &dma_handle)) {
+			pldat->dma_buff_base_v = NULL;
+			pldat->dma_buff_size = 0;
 			netdev_err(ndev,
 				"IRAM not big enough for net buffers, using SDRAM instead.\n");
+		}
 	}
 
 	if (pldat->dma_buff_base_v == 0) {
@@ -1409,7 +1408,7 @@ static int lpc_eth_drv_probe(struct platform_device *pdev)
 	unregister_netdev(ndev);
 err_out_dma_unmap:
 	if (!use_iram_for_net(dev) ||
-	    pldat->dma_buff_size > lpc32xx_return_iram_size())
+	    pldat->dma_buff_size > lpc32xx_return_iram(NULL, NULL))
 		dma_free_coherent(dev, pldat->dma_buff_size,
 				  pldat->dma_buff_base_v,
 				  pldat->dma_buff_base_p);
@@ -1436,7 +1435,7 @@ static int lpc_eth_drv_remove(struct platform_device *pdev)
 	unregister_netdev(ndev);
 
 	if (!use_iram_for_net(&pldat->pdev->dev) ||
-	    pldat->dma_buff_size > lpc32xx_return_iram_size())
+	    pldat->dma_buff_size > lpc32xx_return_iram(NULL, NULL))
 		dma_free_coherent(&pldat->pdev->dev, pldat->dma_buff_size,
 				  pldat->dma_buff_base_v,
 				  pldat->dma_buff_base_p);

include/linux/soc/nxp/lpc32xx-misc.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Author: Kevin Wells <kevin.wells@nxp.com>
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ */
+
+#ifndef __SOC_LPC32XX_MISC_H
+#define __SOC_LPC32XX_MISC_H
+
+#include <linux/types.h>
+
+#ifdef CONFIG_ARCH_LPC32XX
+extern u32 lpc32xx_return_iram(void __iomem **mapbase, dma_addr_t *dmaaddr);
+#else
+static inline u32 lpc32xx_return_iram(void __iomem **mapbase, dma_addr_t *dmaaddr)
+{
+	*mapbase = NULL;
+	*dmaaddr = 0;
+	return 0;
+}
+#endif
+
+#endif  /* __SOC_LPC32XX_MISC_H */