misc: xilinx_sdfec: Add ability to configure LDPC

Add the capability to configure LDPC mode via the ioctl
XSDFEC_ADD_LDPC_CODE_PARAMS.

Tested-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Signed-off-by: Derek Kiernan <derek.kiernan@xilinx.com>
Signed-off-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Link: https://lore.kernel.org/r/1564216438-322406-4-git-send-email-dragan.cvetic@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 422 insertions, 0 deletions

diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index d3dba7e6f896..9be4de07eee2 100644
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/compat.h>
+#include <linux/highmem.h>
 
 #include <uapi/misc/xilinx_sdfec.h>
 
@@ -113,6 +114,57 @@ static struct mutex dev_idr_lock;
 #define XSDFEC_TURBO_SCALE_BIT_POS (8)
 #define XSDFEC_TURBO_SCALE_MAX (15)
 
+/* REG0 Register */
+#define XSDFEC_LDPC_CODE_REG0_ADDR_BASE (0x2000)
+#define XSDFEC_LDPC_CODE_REG0_ADDR_HIGH (0x27F0)
+#define XSDFEC_REG0_N_MIN (4)
+#define XSDFEC_REG0_N_MAX (32768)
+#define XSDFEC_REG0_N_MUL_P (256)
+#define XSDFEC_REG0_N_LSB (0)
+#define XSDFEC_REG0_K_MIN (2)
+#define XSDFEC_REG0_K_MAX (32766)
+#define XSDFEC_REG0_K_MUL_P (256)
+#define XSDFEC_REG0_K_LSB (16)
+
+/* REG1 Register */
+#define XSDFEC_LDPC_CODE_REG1_ADDR_BASE (0x2004)
+#define XSDFEC_LDPC_CODE_REG1_ADDR_HIGH (0x27f4)
+#define XSDFEC_REG1_PSIZE_MIN (2)
+#define XSDFEC_REG1_PSIZE_MAX (512)
+#define XSDFEC_REG1_NO_PACKING_MASK (0x400)
+#define XSDFEC_REG1_NO_PACKING_LSB (10)
+#define XSDFEC_REG1_NM_MASK (0xFF800)
+#define XSDFEC_REG1_NM_LSB (11)
+#define XSDFEC_REG1_BYPASS_MASK (0x100000)
+
+/* REG2 Register */
+#define XSDFEC_LDPC_CODE_REG2_ADDR_BASE (0x2008)
+#define XSDFEC_LDPC_CODE_REG2_ADDR_HIGH (0x27f8)
+#define XSDFEC_REG2_NLAYERS_MIN (1)
+#define XSDFEC_REG2_NLAYERS_MAX (256)
+#define XSDFEC_REG2_NNMQC_MASK (0xFFE00)
+#define XSDFEC_REG2_NMQC_LSB (9)
+#define XSDFEC_REG2_NORM_TYPE_MASK (0x100000)
+#define XSDFEC_REG2_NORM_TYPE_LSB (20)
+#define XSDFEC_REG2_SPECIAL_QC_MASK (0x200000)
+#define XSDFEC_REG2_SPEICAL_QC_LSB (21)
+#define XSDFEC_REG2_NO_FINAL_PARITY_MASK (0x400000)
+#define XSDFEC_REG2_NO_FINAL_PARITY_LSB (22)
+#define XSDFEC_REG2_MAX_SCHEDULE_MASK (0x1800000)
+#define XSDFEC_REG2_MAX_SCHEDULE_LSB (23)
+
+/* REG3 Register */
+#define XSDFEC_LDPC_CODE_REG3_ADDR_BASE (0x200C)
+#define XSDFEC_LDPC_CODE_REG3_ADDR_HIGH (0x27FC)
+#define XSDFEC_REG3_LA_OFF_LSB (8)
+#define XSDFEC_REG3_QC_OFF_LSB (16)
+
+#define XSDFEC_LDPC_REG_JUMP (0x10)
+#define XSDFEC_REG_WIDTH_JUMP (4)
+
+/* The maximum number of pinned pages */
+#define MAX_NUM_PAGES ((XSDFEC_QC_TABLE_DEPTH / PAGE_SIZE) + 1)
+
 /**
  * struct xsdfec_clks - For managing SD-FEC clocks
  * @core_clk: Main processing clock for core
@@ -270,6 +322,275 @@ static int xsdfec_get_turbo(struct xsdfec_dev *xsdfec, void __user *arg)
 	return err;
 }
 
+static int xsdfec_reg0_write(struct xsdfec_dev *xsdfec, u32 n, u32 k, u32 psize,
+			     u32 offset)
+{
+	u32 wdata;
+
+	if (n < XSDFEC_REG0_N_MIN || n > XSDFEC_REG0_N_MAX ||
+	    (n > XSDFEC_REG0_N_MUL_P * psize) || n <= k || ((n % psize) != 0)) {
+		dev_dbg(xsdfec->dev, "N value is not in range");
+		return -EINVAL;
+	}
+	n <<= XSDFEC_REG0_N_LSB;
+
+	if (k < XSDFEC_REG0_K_MIN || k > XSDFEC_REG0_K_MAX ||
+	    (k > XSDFEC_REG0_K_MUL_P * psize) || ((k % psize) != 0)) {
+		dev_dbg(xsdfec->dev, "K value is not in range");
+		return -EINVAL;
+	}
+	k = k << XSDFEC_REG0_K_LSB;
+	wdata = k | n;
+
+	if (XSDFEC_LDPC_CODE_REG0_ADDR_BASE + (offset * XSDFEC_LDPC_REG_JUMP) >
+	    XSDFEC_LDPC_CODE_REG0_ADDR_HIGH) {
+		dev_dbg(xsdfec->dev, "Writing outside of LDPC reg0 space 0x%x",
+			XSDFEC_LDPC_CODE_REG0_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP));
+		return -EINVAL;
+	}
+	xsdfec_regwrite(xsdfec,
+			XSDFEC_LDPC_CODE_REG0_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP),
+			wdata);
+	return 0;
+}
+
+static int xsdfec_reg1_write(struct xsdfec_dev *xsdfec, u32 psize,
+			     u32 no_packing, u32 nm, u32 offset)
+{
+	u32 wdata;
+
+	if (psize < XSDFEC_REG1_PSIZE_MIN || psize > XSDFEC_REG1_PSIZE_MAX) {
+		dev_dbg(xsdfec->dev, "Psize is not in range");
+		return -EINVAL;
+	}
+
+	if (no_packing != 0 && no_packing != 1)
+		dev_dbg(xsdfec->dev, "No-packing bit register invalid");
+	no_packing = ((no_packing << XSDFEC_REG1_NO_PACKING_LSB) &
+		      XSDFEC_REG1_NO_PACKING_MASK);
+
+	if (nm & ~(XSDFEC_REG1_NM_MASK >> XSDFEC_REG1_NM_LSB))
+		dev_dbg(xsdfec->dev, "NM is beyond 10 bits");
+	nm = (nm << XSDFEC_REG1_NM_LSB) & XSDFEC_REG1_NM_MASK;
+
+	wdata = nm | no_packing | psize;
+	if (XSDFEC_LDPC_CODE_REG1_ADDR_BASE + (offset * XSDFEC_LDPC_REG_JUMP) >
+	    XSDFEC_LDPC_CODE_REG1_ADDR_HIGH) {
+		dev_dbg(xsdfec->dev, "Writing outside of LDPC reg1 space 0x%x",
+			XSDFEC_LDPC_CODE_REG1_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP));
+		return -EINVAL;
+	}
+	xsdfec_regwrite(xsdfec,
+			XSDFEC_LDPC_CODE_REG1_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP),
+			wdata);
+	return 0;
+}
+
+static int xsdfec_reg2_write(struct xsdfec_dev *xsdfec, u32 nlayers, u32 nmqc,
+			     u32 norm_type, u32 special_qc, u32 no_final_parity,
+			     u32 max_schedule, u32 offset)
+{
+	u32 wdata;
+
+	if (nlayers < XSDFEC_REG2_NLAYERS_MIN ||
+	    nlayers > XSDFEC_REG2_NLAYERS_MAX) {
+		dev_dbg(xsdfec->dev, "Nlayers is not in range");
+		return -EINVAL;
+	}
+
+	if (nmqc & ~(XSDFEC_REG2_NNMQC_MASK >> XSDFEC_REG2_NMQC_LSB))
+		dev_dbg(xsdfec->dev, "NMQC exceeds 11 bits");
+	nmqc = (nmqc << XSDFEC_REG2_NMQC_LSB) & XSDFEC_REG2_NNMQC_MASK;
+
+	if (norm_type > 1)
+		dev_dbg(xsdfec->dev, "Norm type is invalid");
+	norm_type = ((norm_type << XSDFEC_REG2_NORM_TYPE_LSB) &
+		     XSDFEC_REG2_NORM_TYPE_MASK);
+	if (special_qc > 1)
+		dev_dbg(xsdfec->dev, "Special QC in invalid");
+	special_qc = ((special_qc << XSDFEC_REG2_SPEICAL_QC_LSB) &
+		      XSDFEC_REG2_SPECIAL_QC_MASK);
+
+	if (no_final_parity > 1)
+		dev_dbg(xsdfec->dev, "No final parity check invalid");
+	no_final_parity =
+		((no_final_parity << XSDFEC_REG2_NO_FINAL_PARITY_LSB) &
+		 XSDFEC_REG2_NO_FINAL_PARITY_MASK);
+	if (max_schedule &
+	    ~(XSDFEC_REG2_MAX_SCHEDULE_MASK >> XSDFEC_REG2_MAX_SCHEDULE_LSB))
+		dev_dbg(xsdfec->dev, "Max Schdule exceeds 2 bits");
+	max_schedule = ((max_schedule << XSDFEC_REG2_MAX_SCHEDULE_LSB) &
+			XSDFEC_REG2_MAX_SCHEDULE_MASK);
+
+	wdata = (max_schedule | no_final_parity | special_qc | norm_type |
+		 nmqc | nlayers);
+
+	if (XSDFEC_LDPC_CODE_REG2_ADDR_BASE + (offset * XSDFEC_LDPC_REG_JUMP) >
+	    XSDFEC_LDPC_CODE_REG2_ADDR_HIGH) {
+		dev_dbg(xsdfec->dev, "Writing outside of LDPC reg2 space 0x%x",
+			XSDFEC_LDPC_CODE_REG2_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP));
+		return -EINVAL;
+	}
+	xsdfec_regwrite(xsdfec,
+			XSDFEC_LDPC_CODE_REG2_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP),
+			wdata);
+	return 0;
+}
+
+static int xsdfec_reg3_write(struct xsdfec_dev *xsdfec, u8 sc_off, u8 la_off,
+			     u16 qc_off, u32 offset)
+{
+	u32 wdata;
+
+	wdata = ((qc_off << XSDFEC_REG3_QC_OFF_LSB) |
+		 (la_off << XSDFEC_REG3_LA_OFF_LSB) | sc_off);
+	if (XSDFEC_LDPC_CODE_REG3_ADDR_BASE + (offset * XSDFEC_LDPC_REG_JUMP) >
+	    XSDFEC_LDPC_CODE_REG3_ADDR_HIGH) {
+		dev_dbg(xsdfec->dev, "Writing outside of LDPC reg3 space 0x%x",
+			XSDFEC_LDPC_CODE_REG3_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP));
+		return -EINVAL;
+	}
+	xsdfec_regwrite(xsdfec,
+			XSDFEC_LDPC_CODE_REG3_ADDR_BASE +
+				(offset * XSDFEC_LDPC_REG_JUMP),
+			wdata);
+	return 0;
+}
+
+static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset,
+			      u32 *src_ptr, u32 len, const u32 base_addr,
+			      const u32 depth)
+{
+	u32 reg = 0;
+	u32 res;
+	u32 n, i;
+	u32 *addr = NULL;
+	struct page *page[MAX_NUM_PAGES];
+
+	/*
+	 * Writes that go beyond the length of
+	 * Shared Scale(SC) table should fail
+	 */
+	if ((XSDFEC_REG_WIDTH_JUMP * (offset + len)) > depth) {
+		dev_dbg(xsdfec->dev, "Write exceeds SC table length");
+		return -EINVAL;
+	}
+
+	n = (len * XSDFEC_REG_WIDTH_JUMP) / PAGE_SIZE;
+	if ((len * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE)
+		n += 1;
+
+	res = get_user_pages_fast((unsigned long)src_ptr, n, 0, page);
+	if (res < n) {
+		for (i = 0; i < res; i++)
+			put_page(page[i]);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < n; i++) {
+		addr = kmap(page[i]);
+		do {
+			xsdfec_regwrite(xsdfec,
+					base_addr + ((offset + reg) *
+						     XSDFEC_REG_WIDTH_JUMP),
+					addr[reg]);
+			reg++;
+		} while ((reg < len) &&
+			 ((reg * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE));
+		put_page(page[i]);
+	}
+	return reg;
+}
+
+static int xsdfec_add_ldpc(struct xsdfec_dev *xsdfec, void __user *arg)
+{
+	struct xsdfec_ldpc_params *ldpc;
+	int ret, n;
+
+	ldpc = kzalloc(sizeof(*ldpc), GFP_KERNEL);
+	if (!ldpc)
+		return -ENOMEM;
+
+	ret = copy_from_user(ldpc, arg, sizeof(*ldpc));
+	if (ret)
+		goto err_out;
+
+	if (xsdfec->config.code == XSDFEC_TURBO_CODE) {
+		ret = -EIO;
+		goto err_out;
+	}
+
+	/* Verify Device has not started */
+	if (xsdfec->state == XSDFEC_STARTED) {
+		ret = -EIO;
+		goto err_out;
+	}
+
+	if (xsdfec->config.code_wr_protect) {
+		ret = -EIO;
+		goto err_out;
+	}
+
+	/* Write Reg 0 */
+	ret = xsdfec_reg0_write(xsdfec, ldpc->n, ldpc->k, ldpc->psize,
+				ldpc->code_id);
+	if (ret)
+		goto err_out;
+
+	/* Write Reg 1 */
+	ret = xsdfec_reg1_write(xsdfec, ldpc->psize, ldpc->no_packing, ldpc->nm,
+				ldpc->code_id);
+	if (ret)
+		goto err_out;
+
+	/* Write Reg 2 */
+	ret = xsdfec_reg2_write(xsdfec, ldpc->nlayers, ldpc->nmqc,
+				ldpc->norm_type, ldpc->special_qc,
+				ldpc->no_final_parity, ldpc->max_schedule,
+				ldpc->code_id);
+	if (ret)
+		goto err_out;
+
+	/* Write Reg 3 */
+	ret = xsdfec_reg3_write(xsdfec, ldpc->sc_off, ldpc->la_off,
+				ldpc->qc_off, ldpc->code_id);
+	if (ret)
+		goto err_out;
+
+	/* Write Shared Codes */
+	n = ldpc->nlayers / 4;
+	if (ldpc->nlayers % 4)
+		n++;
+
+	ret = xsdfec_table_write(xsdfec, ldpc->sc_off, ldpc->sc_table, n,
+				 XSDFEC_LDPC_SC_TABLE_ADDR_BASE,
+				 XSDFEC_SC_TABLE_DEPTH);
+	if (ret < 0)
+		goto err_out;
+
+	ret = xsdfec_table_write(xsdfec, 4 * ldpc->la_off, ldpc->la_table,
+				 ldpc->nlayers, XSDFEC_LDPC_LA_TABLE_ADDR_BASE,
+				 XSDFEC_LA_TABLE_DEPTH);
+	if (ret < 0)
+		goto err_out;
+
+	ret = xsdfec_table_write(xsdfec, 4 * ldpc->qc_off, ldpc->qc_table,
+				 ldpc->nqc, XSDFEC_LDPC_QC_TABLE_ADDR_BASE,
+				 XSDFEC_QC_TABLE_DEPTH);
+	if (ret > 0)
+		ret = 0;
+err_out:
+	kfree(ldpc);
+	return ret;
+}
+
 static u32
 xsdfec_translate_axis_width_cfg_val(enum xsdfec_axis_width axis_width_cfg)
 {
@@ -366,6 +687,9 @@ static long xsdfec_dev_ioctl(struct file *fptr, unsigned int cmd,
 	case XSDFEC_GET_TURBO:
 		rval = xsdfec_get_turbo(xsdfec, arg);
 		break;
+	case XSDFEC_ADD_LDPC_CODE_PARAMS:
+		rval = xsdfec_add_ldpc(xsdfec, arg);
+		break;
 	default:
 		/* Should not get here */
 		break;
diff --git a/include/uapi/misc/xilinx_sdfec.h b/include/uapi/misc/xilinx_sdfec.h
index 34f32c37261d..ce532a5e3e81 100644
--- a/include/uapi/misc/xilinx_sdfec.h
+++ b/include/uapi/misc/xilinx_sdfec.h
@@ -13,6 +13,22 @@
 
 #include <linux/types.h>
 
+/* Shared LDPC Tables */
+#define XSDFEC_LDPC_SC_TABLE_ADDR_BASE (0x10000)
+#define XSDFEC_LDPC_SC_TABLE_ADDR_HIGH (0x10400)
+#define XSDFEC_LDPC_LA_TABLE_ADDR_BASE (0x18000)
+#define XSDFEC_LDPC_LA_TABLE_ADDR_HIGH (0x19000)
+#define XSDFEC_LDPC_QC_TABLE_ADDR_BASE (0x20000)
+#define XSDFEC_LDPC_QC_TABLE_ADDR_HIGH (0x28000)
+
+/* LDPC tables depth */
+#define XSDFEC_SC_TABLE_DEPTH                                                  \
+	(XSDFEC_LDPC_SC_TABLE_ADDR_HIGH - XSDFEC_LDPC_SC_TABLE_ADDR_BASE)
+#define XSDFEC_LA_TABLE_DEPTH                                                  \
+	(XSDFEC_LDPC_LA_TABLE_ADDR_HIGH - XSDFEC_LDPC_LA_TABLE_ADDR_BASE)
+#define XSDFEC_QC_TABLE_DEPTH                                                  \
+	(XSDFEC_LDPC_QC_TABLE_ADDR_HIGH - XSDFEC_LDPC_QC_TABLE_ADDR_BASE)
+
 /**
  * enum xsdfec_code - Code Type.
  * @XSDFEC_TURBO_CODE: Driver is configured for Turbo mode.
@@ -127,6 +143,53 @@ struct xsdfec_turbo {
 };
 
 /**
+ * struct xsdfec_ldpc_params - User data for LDPC codes.
+ * @n: Number of code word bits
+ * @k: Number of information bits
+ * @psize: Size of sub-matrix
+ * @nlayers: Number of layers in code
+ * @nqc: Quasi Cyclic Number
+ * @nmqc: Number of M-sized QC operations in parity check matrix
+ * @nm: Number of M-size vectors in N
+ * @norm_type: Normalization required or not
+ * @no_packing: Determines if multiple QC ops should be performed
+ * @special_qc: Sub-Matrix property for Circulant weight > 0
+ * @no_final_parity: Decide if final parity check needs to be performed
+ * @max_schedule: Experimental code word scheduling limit
+ * @sc_off: SC offset
+ * @la_off: LA offset
+ * @qc_off: QC offset
+ * @sc_table: Pointer to SC Table which must be page aligned
+ * @la_table: Pointer to LA Table which must be page aligned
+ * @qc_table: Pointer to QC Table which must be page aligned
+ * @code_id: LDPC Code
+ *
+ * This structure describes the LDPC code that is passed to the driver by the
+ * application.
+ */
+struct xsdfec_ldpc_params {
+	__u32 n;
+	__u32 k;
+	__u32 psize;
+	__u32 nlayers;
+	__u32 nqc;
+	__u32 nmqc;
+	__u32 nm;
+	__u32 norm_type;
+	__u32 no_packing;
+	__u32 special_qc;
+	__u32 no_final_parity;
+	__u32 max_schedule;
+	__u32 sc_off;
+	__u32 la_off;
+	__u32 qc_off;
+	__u32 *sc_table;
+	__u32 *la_table;
+	__u32 *qc_table;
+	__u16 code_id;
+};
+
+/**
  * struct xsdfec_status - Status of SD-FEC core.
  * @state: State of the SD-FEC core
  * @activity: Describes if the SD-FEC instance is Active
@@ -170,6 +233,20 @@ struct xsdfec_config {
 	__s8 code_wr_protect;
 };
 
+/**
+ * struct xsdfec_ldpc_param_table_sizes - Used to store sizes of SD-FEC table
+ *					  entries for an individual LPDC code
+ *					  parameter.
+ * @sc_size: Size of SC table used
+ * @la_size: Size of LA table used
+ * @qc_size: Size of QC table used
+ */
+struct xsdfec_ldpc_param_table_sizes {
+	__u32 sc_size;
+	__u32 la_size;
+	__u32 qc_size;
+};
+
 /*
  * XSDFEC IOCTL List
  */
@@ -190,6 +267,27 @@ struct xsdfec_config {
  */
 #define XSDFEC_SET_TURBO _IOW(XSDFEC_MAGIC, 4, struct xsdfec_turbo)
 /**
+ * DOC: XSDFEC_ADD_LDPC_CODE_PARAMS
+ * @Parameters
+ *
+ * @struct xsdfec_ldpc_params *
+ *	Pointer to the &struct xsdfec_ldpc_params that contains the LDPC code
+ *	parameters to be added to the SD-FEC Block
+ *
+ * @Description
+ * ioctl to add an LDPC code to the SD-FEC LDPC codes
+ *
+ * This can only be used when:
+ *
+ * - Driver is in the XSDFEC_STOPPED state
+ *
+ * - SD-FEC core is configured as LPDC
+ *
+ * - SD-FEC Code Write Protection is disabled
+ */
+#define XSDFEC_ADD_LDPC_CODE_PARAMS                                            \
+	_IOW(XSDFEC_MAGIC, 5, struct xsdfec_ldpc_params)
+/**
  * DOC: XSDFEC_GET_TURBO
  * @Parameters
  *