amd-xgbe: Prepare for a new PCS register access method

Prepare the code to be able to support accessing of the PCS registers
in a new way, while maintaining the current access method. Provide a
version specific field that indicates the method to use.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-common.h

@@ -852,14 +852,9 @@
 #define MTL_TSA_SP			0x00
 #define MTL_TSA_ETS			0x02
 
-/* PCS MMD select register offset
- *  The MMD select register is used for accessing PCS registers
- *  when the underlying APB3 interface is using indirect addressing.
- *  Indirect addressing requires accessing registers in two phases,
- *  an address phase and a data phase.  The address phases requires
- *  writing an address selection value to the MMD select regiesters.
- */
-#define PCS_MMD_SELECT			0xff
+/* PCS register offsets */
+#define PCS_V1_WINDOW_SELECT		0x03fc
+#define PCS_V2_WINDOW_SELECT		0x9064
 
 /* SerDes integration register offsets */
 #define SIR0_KR_RT_1			0x002c
@@ -1241,12 +1236,18 @@ do {									\
 /* Macros for building, reading or writing register values or bits
  * within the register values of XPCS registers.
  */
-#define XPCS_IOWRITE(_pdata, _off, _val)				\
+#define XPCS32_IOWRITE(_pdata, _off, _val)				\
 	iowrite32(_val, (_pdata)->xpcs_regs + (_off))
 
-#define XPCS_IOREAD(_pdata, _off)					\
+#define XPCS32_IOREAD(_pdata, _off)					\
 	ioread32((_pdata)->xpcs_regs + (_off))
 
+#define XPCS16_IOWRITE(_pdata, _off, _val)				\
+	iowrite16(_val, (_pdata)->xpcs_regs + (_off))
+
+#define XPCS16_IOREAD(_pdata, _off)					\
+	ioread16((_pdata)->xpcs_regs + (_off))
+
 /* Macros for building, reading or writing register values or bits
  * within the register values of SerDes integration registers.
  */

drivers/net/ethernet/amd/xgbe/xgbe-dev.c

@@ -1026,8 +1026,71 @@ static int xgbe_config_rx_mode(struct xgbe_prv_data *pdata)
 	return 0;
 }
 
-static int xgbe_read_mmd_regs(struct xgbe_prv_data *pdata, int prtad,
-			      int mmd_reg)
+static int xgbe_read_mmd_regs_v2(struct xgbe_prv_data *pdata, int prtad,
+				 int mmd_reg)
+{
+	unsigned long flags;
+	unsigned int mmd_address, index, offset;
+	int mmd_data;
+
+	if (mmd_reg & MII_ADDR_C45)
+		mmd_address = mmd_reg & ~MII_ADDR_C45;
+	else
+		mmd_address = (pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+
+	/* The PCS registers are accessed using mmio. The underlying
+	 * management interface uses indirect addressing to access the MMD
+	 * register sets. This requires accessing of the PCS register in two
+	 * phases, an address phase and a data phase.
+	 *
+	 * The mmio interface is based on 16-bit offsets and values. All
+	 * register offsets must therefore be adjusted by left shifting the
+	 * offset 1 bit and reading 16 bits of data.
+	 */
+	mmd_address <<= 1;
+	index = mmd_address & ~pdata->xpcs_window_mask;
+	offset = pdata->xpcs_window + (mmd_address & pdata->xpcs_window_mask);
+
+	spin_lock_irqsave(&pdata->xpcs_lock, flags);
+	XPCS32_IOWRITE(pdata, PCS_V2_WINDOW_SELECT, index);
+	mmd_data = XPCS16_IOREAD(pdata, offset);
+	spin_unlock_irqrestore(&pdata->xpcs_lock, flags);
+
+	return mmd_data;
+}
+
+static void xgbe_write_mmd_regs_v2(struct xgbe_prv_data *pdata, int prtad,
+				   int mmd_reg, int mmd_data)
+{
+	unsigned long flags;
+	unsigned int mmd_address, index, offset;
+
+	if (mmd_reg & MII_ADDR_C45)
+		mmd_address = mmd_reg & ~MII_ADDR_C45;
+	else
+		mmd_address = (pdata->mdio_mmd << 16) | (mmd_reg & 0xffff);
+
+	/* The PCS registers are accessed using mmio. The underlying
+	 * management interface uses indirect addressing to access the MMD
+	 * register sets. This requires accessing of the PCS register in two
+	 * phases, an address phase and a data phase.
+	 *
+	 * The mmio interface is based on 16-bit offsets and values. All
+	 * register offsets must therefore be adjusted by left shifting the
+	 * offset 1 bit and writing 16 bits of data.
+	 */
+	mmd_address <<= 1;
+	index = mmd_address & ~pdata->xpcs_window_mask;
+	offset = pdata->xpcs_window + (mmd_address & pdata->xpcs_window_mask);
+
+	spin_lock_irqsave(&pdata->xpcs_lock, flags);
+	XPCS32_IOWRITE(pdata, PCS_V2_WINDOW_SELECT, index);
+	XPCS16_IOWRITE(pdata, offset, mmd_data);
+	spin_unlock_irqrestore(&pdata->xpcs_lock, flags);
+}
+
+static int xgbe_read_mmd_regs_v1(struct xgbe_prv_data *pdata, int prtad,
+				 int mmd_reg)
 {
 	unsigned long flags;
 	unsigned int mmd_address;
@@ -1048,15 +1111,15 @@ static int xgbe_read_mmd_regs(struct xgbe_prv_data *pdata, int prtad,
 	 * offset 2 bits and reading 32 bits of data.
 	 */
 	spin_lock_irqsave(&pdata->xpcs_lock, flags);
-	XPCS_IOWRITE(pdata, PCS_MMD_SELECT << 2, mmd_address >> 8);
-	mmd_data = XPCS_IOREAD(pdata, (mmd_address & 0xff) << 2);
+	XPCS32_IOWRITE(pdata, PCS_V1_WINDOW_SELECT, mmd_address >> 8);
+	mmd_data = XPCS32_IOREAD(pdata, (mmd_address & 0xff) << 2);
 	spin_unlock_irqrestore(&pdata->xpcs_lock, flags);
 
 	return mmd_data;
 }
 
-static void xgbe_write_mmd_regs(struct xgbe_prv_data *pdata, int prtad,
-				int mmd_reg, int mmd_data)
+static void xgbe_write_mmd_regs_v1(struct xgbe_prv_data *pdata, int prtad,
+				   int mmd_reg, int mmd_data)
 {
 	unsigned int mmd_address;
 	unsigned long flags;
@@ -1073,14 +1136,40 @@ static void xgbe_write_mmd_regs(struct xgbe_prv_data *pdata, int prtad,
 	 *
 	 * The mmio interface is based on 32-bit offsets and values. All
 	 * register offsets must therefore be adjusted by left shifting the
-	 * offset 2 bits and reading 32 bits of data.
+	 * offset 2 bits and writing 32 bits of data.
 	 */
 	spin_lock_irqsave(&pdata->xpcs_lock, flags);
-	XPCS_IOWRITE(pdata, PCS_MMD_SELECT << 2, mmd_address >> 8);
-	XPCS_IOWRITE(pdata, (mmd_address & 0xff) << 2, mmd_data);
+	XPCS32_IOWRITE(pdata, PCS_V1_WINDOW_SELECT, mmd_address >> 8);
+	XPCS32_IOWRITE(pdata, (mmd_address & 0xff) << 2, mmd_data);
 	spin_unlock_irqrestore(&pdata->xpcs_lock, flags);
 }
 
+static int xgbe_read_mmd_regs(struct xgbe_prv_data *pdata, int prtad,
+			      int mmd_reg)
+{
+	switch (pdata->vdata->xpcs_access) {
+	case XGBE_XPCS_ACCESS_V1:
+		return xgbe_read_mmd_regs_v1(pdata, prtad, mmd_reg);
+
+	case XGBE_XPCS_ACCESS_V2:
+	default:
+		return xgbe_read_mmd_regs_v2(pdata, prtad, mmd_reg);
+	}
+}
+
+static void xgbe_write_mmd_regs(struct xgbe_prv_data *pdata, int prtad,
+				int mmd_reg, int mmd_data)
+{
+	switch (pdata->vdata->xpcs_access) {
+	case XGBE_XPCS_ACCESS_V1:
+		return xgbe_write_mmd_regs_v1(pdata, prtad, mmd_reg, mmd_data);
+
+	case XGBE_XPCS_ACCESS_V2:
+	default:
+		return xgbe_write_mmd_regs_v2(pdata, prtad, mmd_reg, mmd_data);
+	}
+}
+
 static int xgbe_tx_complete(struct xgbe_ring_desc *rdesc)
 {
 	return !XGMAC_GET_BITS_LE(rdesc->desc3, TX_NORMAL_DESC3, OWN);

drivers/net/ethernet/amd/xgbe/xgbe-main.c

@@ -785,6 +785,7 @@ static int xgbe_resume(struct device *dev)
 
 static const struct xgbe_version_data xgbe_v1 = {
 	.init_function_ptrs_phy_impl	= xgbe_init_function_ptrs_phy_v1,
+	.xpcs_access			= XGBE_XPCS_ACCESS_V1,
 };
 
 #ifdef CONFIG_ACPI

drivers/net/ethernet/amd/xgbe/xgbe.h

@@ -471,6 +471,11 @@ enum xgbe_speed {
 	XGBE_SPEEDS,
 };
 
+enum xgbe_xpcs_access {
+	XGBE_XPCS_ACCESS_V1 = 0,
+	XGBE_XPCS_ACCESS_V2,
+};
+
 enum xgbe_an_mode {
 	XGBE_AN_MODE_CL73 = 0,
 	XGBE_AN_MODE_CL37,
@@ -798,6 +803,7 @@ struct xgbe_hw_features {
 
 struct xgbe_version_data {
 	void (*init_function_ptrs_phy_impl)(struct xgbe_phy_if *);
+	enum xgbe_xpcs_access xpcs_access;
 };
 
 struct xgbe_prv_data {
@@ -826,6 +832,9 @@ struct xgbe_prv_data {
 
 	/* XPCS indirect addressing lock */
 	spinlock_t xpcs_lock;
+	unsigned int xpcs_window;
+	unsigned int xpcs_window_size;
+	unsigned int xpcs_window_mask;
 
 	/* RSS addressing mutex */
 	struct mutex rss_mutex;