[PATCH RESEND 2/3] mailbox: Add Broadcom PDC mailbox driver

Rob Rice
2016-06-14T14:04:10Z

The Broadcom PDC mailbox driver is a mailbox controller that
manages data transfers to and from one or more offload engines.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
---
drivers/mailbox/Kconfig | 9 +
drivers/mailbox/Makefile | 2 +
drivers/mailbox/mailbox-pdc/Makefile | 8 +
drivers/mailbox/mailbox-pdc/pdc.c | 1181 +++++++++++++++++++++++++++++++
drivers/mailbox/mailbox-pdc/pdc.h | 303 ++++++++
drivers/mailbox/mailbox-pdc/pdc_debug.c | 101 +++
drivers/mailbox/mailbox-pdc/pdc_debug.h | 24 +
include/linux/mailbox/brcm-message.h | 56 ++
8 files changed, 1684 insertions(+)
create mode 100644 drivers/mailbox/mailbox-pdc/Makefile
create mode 100644 drivers/mailbox/mailbox-pdc/pdc.c
create mode 100644 drivers/mailbox/mailbox-pdc/pdc.h
create mode 100644 drivers/mailbox/mailbox-pdc/pdc_debug.c
create mode 100644 drivers/mailbox/mailbox-pdc/pdc_debug.h
create mode 100644 include/linux/mailbox/brcm-message.h

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 5305923..19c8c9a 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -123,4 +123,13 @@ config XGENE_SLIMPRO_MBOX
It is used to send short messages between ARM64-bit cores and
the SLIMpro Management Engine, primarily for PM. Say Y here if you
want to use the APM X-Gene SLIMpro IPCM support.
+
+config BCM_PDC_MBOX
+ tristate "Broadcom PDC Mailbox"
+ depends on ARM64
+ default ARCH_BCM_IPROC
+ help
+ Mailbox implementation for the Broadcom PDC ring manager,
+ which provides access to various offload engines on Broadcom
+ SoCs. Say Y here if you want to use the Broadcom PDC.
endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 0be3e74..2c14a03 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -25,3 +25,5 @@ obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o

obj-$(CONFIG_HI6220_MBOX) += hi6220-mailbox.o
+
+obj-$(CONFIG_BCM_PDC_MBOX) += mailbox-pdc/
diff --git a/drivers/mailbox/mailbox-pdc/Makefile b/drivers/mailbox/mailbox-pdc/Makefile
new file mode 100644
index 0000000..5dc78c3
--- /dev/null
+++ b/drivers/mailbox/mailbox-pdc/Makefile
@@ -0,0 +1,8 @@
+# Makefile for Broadcom PDC Mailbox driver
+
+# Uncomment to enable debug tracing in the PDC driver
+# CFLAGS_pdc.o := -DDEBUG
+# CFLAGS_pdc_debug.o := -DDEBUG
+
+pdc-mbox-objs := pdc.o pdc_debug.o
+obj-$(CONFIG_BCM_PDC_MBOX) := pdc-mbox.o
diff --git a/drivers/mailbox/mailbox-pdc/pdc.c b/drivers/mailbox/mailbox-pdc/pdc.c
new file mode 100644
index 0000000..1c24ea8
--- /dev/null
+++ b/drivers/mailbox/mailbox-pdc/pdc.c
@@ -0,0 +1,1181 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation (the "GPL").
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 (GPLv2) for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 (GPLv2) along with this source code.
+ */
+
+/*
+ * Broadcom PDC Mailbox Driver
+ * The PDC provides a ring based programming interface to one or more hardware
+ * offload engines. For example, the PDC driver works with both SPU-M and SPU2
+ * cryptographic offload hardware. In some chips the PDC is referred to as MDE.
+ *
+ * The PDC driver registers with the Linux mailbox framework as a mailbox
+ * controller, once for each PDC instance. Ring 0 for each PDC is registered as
+ * a mailbox channel. The PDC driver uses interrupts to determine when data
+ * transfers to and from an offload engine are complete. The PDC driver uses
+ * threaded IRQs so that response messages are handled outside of interrupt
+ * context.
+ *
+ * The PDC driver allows multiple messages to be pending in the descriptor
+ * rings. The tx_msg_start descriptor index indicates where the last message
+ * starts. The txin_numd value at this index indicates how many descriptor
+ * indexes make up the message. Similar state is kept on the receive side. When
+ * an rx interrupt indicates a response is ready, the PDC driver processes numd
+ * descriptors from the tx and rx ring, thus processing one response at a time.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/brcm-message.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+
+#include "pdc.h"
+#include "pdc_debug.h"
+
+/* Length of BCM header at start of SPU msg, in bytes */
+#define BCM_HDR_LEN 8
+
+/*
+ * PDC driver reserves ringset 0 on each SPU for its own use. The driver does
+ * not currently support use of multiple ringsets on a single PDC engine.
+ */
+#define PDC_RINGSET 0
+
+/*
+ * Interrupt mask and status definitions. Enable interrupts for tx and rx on
+ * ring 0
+ */
+#define PDC_XMTINT_0 (24 + PDC_RINGSET)
+#define PDC_RCVINT_0 (16 + PDC_RINGSET)
+#define PDC_XMTINTEN_0 BIT(PDC_XMTINT_0)
+#define PDC_RCVINTEN_0 BIT(PDC_RCVINT_0)
+#define PDC_INTMASK (PDC_XMTINTEN_0 | PDC_RCVINTEN_0)
+#define PDC_LAZY_FRAMECOUNT 1
+#define PDC_LAZY_TIMEOUT 10000
+#define PDC_LAZY_INT (PDC_LAZY_TIMEOUT | (PDC_LAZY_FRAMECOUNT << 24))
+#define PDC_INTMASK_OFFSET 0x24
+#define PDC_INTSTATUS_OFFSET 0x20
+#define PDC_RCVLAZY0_OFFSET (0x30 + 4 * PDC_RINGSET)
+
+/*
+ * For SPU2, configure MDE_CKSUM_CONTROL to write 17 bytes of metadata
+ * before frame
+ */
+#define PDC_SPU2_RESP_HDR_LEN 17
+#define PDC_CKSUM_CTRL BIT(27)
+#define PDC_CKSUM_CTRL_OFFSET 0x400
+
+#define PDC_SPUM_RESP_HDR_LEN 32
+
+/*
+ * Sets the following bits for write to transmit control reg:
+ * 0 - XmtEn - enable activity on the tx channel
+ * 11 - PtyChkDisable - parity check is disabled
+ * 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory
+ */
+#define PDC_TX_CTL 0x000C0801
+
+/*
+ * Sets the following bits for write to receive control reg:
+ * 0 - RcvEn - enable activity on the rx channel
+ * 7:1 - RcvOffset - size in bytes of status region at start of rx frame buf
+ * 9 - SepRxHdrDescEn - place start of new frames only in descriptors
+ * that have StartOfFrame set
+ * 10 - OflowContinue - on rx FIFO overflow, clear rx fifo, discard all
+ * remaining bytes in current frame, report error
+ * in rx frame status for current frame
+ * 11 - PtyChkDisable - parity check is disabled
+ * 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory
+ */
+#define PDC_RX_CTL 0x000C0E01
+
+#define CRYPTO_D64_RS0_CD_MASK ((PDC_RING_ENTRIES * RING_ENTRY_SIZE) - 1)
+
+/* descriptor flags */
+#define D64_CTRL1_EOT BIT(28) /* end of descriptor table */
+#define D64_CTRL1_IOC BIT(29) /* interrupt on complete */
+#define D64_CTRL1_EOF BIT(30) /* end of frame */
+#define D64_CTRL1_SOF BIT(31) /* start of frame */
+
+#define RX_STATUS_OVERFLOW 0x00800000
+#define RX_STATUS_LEN 0x0000FFFF
+
+#define PDC_TXREGS_OFFSET 0x200
+#define PDC_RXREGS_OFFSET 0x220
+
+/* Maximum size buffer the DMA engine can handle */
+#define PDC_DMA_BUF_MAX 16384
+
+/* Global variables */
+
+struct pdc_globals {
+ /* Actual number of SPUs in hardware, as reported by device tree */
+ u32 num_spu;
+};
+
+static struct pdc_globals pdcg;
+
+/**
+ * pdc_build_rxd() - Build DMA descriptor to receive SPU result.
+ * @pdcs: PDC state for SPU that will generate result
+ * @dma_addr: DMA address of buffer that descriptor is being built for
+ * @buf_len: Length of the receive buffer, in bytes
+ * @flags: Flags to be stored in descriptor
+ */
+static inline void
+pdc_build_rxd(struct pdc_state *pdcs, dma_addr_t dma_addr,
+ u32 buf_len, u32 flags)
+{
+ struct device *dev = &pdcs->pdev->dev;
+
+ dev_dbg(dev,
+ "Writing rx descriptor for PDC %u at index %u with length %u. flags %#x\n",
+ pdcs->pdc_idx, pdcs->rxout, buf_len, flags);
+
+ iowrite32(lower_32_bits(dma_addr),
+ (void *)&pdcs->rxd_64[pdcs->rxout].addrlow);
+ iowrite32(upper_32_bits(dma_addr),
+ (void *)&pdcs->rxd_64[pdcs->rxout].addrhigh);
+ iowrite32(flags, (void *)&pdcs->rxd_64[pdcs->rxout].ctrl1);
+ iowrite32(buf_len, (void *)&pdcs->rxd_64[pdcs->rxout].ctrl2);
+ /* bump ring index and return */
+ pdcs->rxout = NEXTRXD(pdcs->rxout, pdcs->nrxpost);
+}
+
+/**
+ * pdc_build_txd() - Build a DMA descriptor to transmit a SPU request to
+ * hardware.
+ * @pdcs: PDC state for the SPU that will process this request
+ * @dma_addr: DMA address of packet to be transmitted
+ * @buf_len: Length of tx buffer, in bytes
+ * @flags: Flags to be stored in descriptor
+ */
+static inline void
+pdc_build_txd(struct pdc_state *pdcs, dma_addr_t dma_addr, u32 buf_len,
+ u32 flags)
+{
+ struct device *dev = &pdcs->pdev->dev;
+
+ dev_dbg(dev,
+ "Writing tx descriptor for PDC %u at index %u with length %u, flags %#x\n",
+ pdcs->pdc_idx, pdcs->txout, buf_len, flags);
+
+ iowrite32(lower_32_bits(dma_addr),
+ (void *)&pdcs->txd_64[pdcs->txout].addrlow);
+ iowrite32(upper_32_bits(dma_addr),
+ (void *)&pdcs->txd_64[pdcs->txout].addrhigh);
+ iowrite32(flags, (void *)&pdcs->txd_64[pdcs->txout].ctrl1);
+ iowrite32(buf_len, (void *)&pdcs->txd_64[pdcs->txout].ctrl2);
+
+ /* bump ring index and return */
+ pdcs->txout = NEXTTXD(pdcs->txout, pdcs->ntxpost);
+}
+
+/**
+ * pdc_receive() - Receive a response message from a given SPU.
+ * @pdcs: PDC state for the SPU to receive from
+ * @mssg: mailbox message to be returned to client
+ *
+ * When the return code indicates success, the response message is available in
+ * the receive buffers provided prior to submission of the request.
+ *
+ * Input:
+ * pdcs - PDC state structure for the SPU to be polled
+ * mssg - mailbox message to be returned to client. This function sets the
+ * context pointer on the message to help the client associate the
+ * response with a request.
+ *
+ * Return: PDC_SUCCESS if one or more receive descriptors was processed
+ * -EAGAIN indicates that no response message is available
+ * -EIO an error occurred
+ */
+static int
+pdc_receive(struct pdc_state *pdcs, struct brcm_message *mssg)
+{
+ struct device *dev = &pdcs->pdev->dev;
+ u32 len, rx_status;
+ u32 num_frags;
+ int i;
+ u8 *resp_hdr; /* virtual addr of start of resp message DMA header */
+ u32 frags_rdy; /* number of fragments ready to read */
+ u32 rx_idx; /* ring index of start of receive frame */
+ dma_addr_t resp_hdr_daddr;
+
+ spin_lock(&pdcs->pdc_lock);
+
+ /*
+ * return if a complete response message is not yet ready.
+ * rxin_numd[rxin] is the number of fragments in the next msg
+ * to read.
+ */
+ frags_rdy = NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr, pdcs->nrxpost);
+ if ((frags_rdy == 0) || (frags_rdy < pdcs->rxin_numd[pdcs->rxin])) {
+ /* See if the hw has written more fragments than we know */
+ pdcs->last_rx_curr =
+ (ioread32((void *)&pdcs->rxregs_64->status0) &
+ CRYPTO_D64_RS0_CD_MASK) / RING_ENTRY_SIZE;
+ frags_rdy = NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr,
+ pdcs->nrxpost);
+ if ((frags_rdy == 0) ||
+ (frags_rdy < pdcs->rxin_numd[pdcs->rxin])) {
+ /* No response ready */
+ spin_unlock(&pdcs->pdc_lock);
+ return -EAGAIN;
+ }
+ /* can't read descriptors/data until write index is read */
+ rmb();
+ }
+
+ num_frags = pdcs->txin_numd[pdcs->txin];
+ dma_unmap_sg(dev, pdcs->src_sg[pdcs->txin],
+ sg_nents(pdcs->src_sg[pdcs->txin]), DMA_TO_DEVICE);
+
+ for (i = 0; i < num_frags; i++)
+ pdcs->txin = NEXTTXD(pdcs->txin, pdcs->ntxpost);
+
+ dev_dbg(dev, "PDC %u reclaimed %d tx descriptors",
+ pdcs->pdc_idx, num_frags);
+
+ rx_idx = pdcs->rxin;
+ num_frags = pdcs->rxin_numd[rx_idx];
+ /* Return opaque context with result */
+ mssg->ctx = pdcs->rxp_ctx[rx_idx];
+ pdcs->rxp_ctx[rx_idx] = NULL;
+ resp_hdr = pdcs->resp_hdr[rx_idx];
+ resp_hdr_daddr = pdcs->resp_hdr_daddr[rx_idx];
+ dma_unmap_sg(dev, pdcs->dst_sg[rx_idx],
+ sg_nents(pdcs->dst_sg[rx_idx]), DMA_FROM_DEVICE);
+
+ for (i = 0; i < num_frags; i++)
+ pdcs->rxin = NEXTRXD(pdcs->rxin, pdcs->nrxpost);
+
+ spin_unlock(&pdcs->pdc_lock);
+
+ dev_dbg(dev, "PDC %u reclaimed %d rx descriptors",
+ pdcs->pdc_idx, num_frags);
+
+ dev_dbg(dev,
+ "PDC %u txin %u, txout %u, rxin %u, rxout %u, last_rx_curr %u\n",
+ pdcs->pdc_idx, pdcs->txin, pdcs->txout, pdcs->rxin,
+ pdcs->rxout, pdcs->last_rx_curr);
+
+ if (pdcs->pdc_resp_hdr_len == PDC_SPUM_RESP_HDR_LEN) {
+ /*
+ * For SPU-M, get length of response msg and rx overflow status.
+ */
+ rx_status = *((u32 *)resp_hdr);
+ len = rx_status & RX_STATUS_LEN;
+ dev_dbg(dev,
+ "SPU response length %u bytes", len);
+ if (unlikely(((rx_status & RX_STATUS_OVERFLOW) || (!len)))) {
+ if (rx_status & RX_STATUS_OVERFLOW) {
+ dev_err_ratelimited(dev,
+ "crypto receive overflow");
+ pdcs->rx_oflow++;
+ } else {
+ dev_info_ratelimited(dev, "crypto rx len = 0");
+ }
+ return -EIO;
+ }
+ }
+
+ dma_pool_free(pdcs->rx_buf_pool, resp_hdr, resp_hdr_daddr);
+
+ pdcs->pdc_replies++;
+ /* if we read one or more rx descriptors, claim success */
+ if (num_frags > 0)
+ return PDC_SUCCESS;
+ else
+ return -EIO;
+}
+
+/**
+ * pdc_tx_list_sg_add() - Add the buffers in a scatterlist to the transmit
+ * descriptors for a given SPU. The scatterlist buffers contain the data for a
+ * SPU request message.
+ * @spu_idx: The index of the SPU to submit the request to, [0, max_spu)
+ * @sg: Scatterlist whose buffers contain part of the SPU request
+ *
+ * If a scatterlist buffer is larger than PDC_DMA_BUF_MAX, multiple descriptors
+ * are written for that buffer, each <= PDC_DMA_BUF_MAX byte in length.
+ *
+ * Return: PDC_SUCCESS if successful
+ * < 0 otherwise
+ */
+static int pdc_tx_list_sg_add(struct pdc_state *pdcs, struct scatterlist *sg)
+{
+ u32 flags = 0;
+ u32 eot;
+ u32 tx_avail;
+
+ /*
+ * Num descriptors needed. Conservatively assume we need a descriptor
+ * for every entry in sg.
+ */
+ u32 num_desc;
+ u32 desc_w = 0; /* Number of tx descriptors written */
+ u32 bufcnt; /* Number of bytes of buffer pointed to by descriptor */
+ dma_addr_t databufptr; /* DMA address to put in descriptor */
+
+ num_desc = (u32)sg_nents(sg);
+
+ /* check whether enough tx descriptors are available */
+ tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout,
+ pdcs->ntxpost);
+ if (unlikely(num_desc > tx_avail)) {
+ pdcs->txnobuf++;
+ return -ENOSPC;
+ }
+
+ /* build tx descriptors */
+ if (pdcs->tx_msg_start == pdcs->txout) {
+ /* Start of frame */
+ pdcs->txin_numd[pdcs->tx_msg_start] = 0;
+ pdcs->src_sg[pdcs->txout] = sg;
+ flags = D64_CTRL1_SOF;
+ }
+
+ while (sg) {
+ if (unlikely(pdcs->txout == (pdcs->ntxd - 1)))
+ eot = D64_CTRL1_EOT;
+ else
+ eot = 0;
+
+ /*
+ * If sg buffer larger than PDC limit, split across
+ * multiple descriptors
+ */
+ bufcnt = sg_dma_len(sg);
+ databufptr = sg_dma_address(sg);
+ while (bufcnt > PDC_DMA_BUF_MAX) {
+ pdc_build_txd(pdcs, databufptr, PDC_DMA_BUF_MAX,
+ flags | eot);
+ desc_w++;
+ bufcnt -= PDC_DMA_BUF_MAX;
+ databufptr += PDC_DMA_BUF_MAX;
+ if (unlikely(pdcs->txout == (pdcs->ntxd - 1)))
+ eot = D64_CTRL1_EOT;
+ else
+ eot = 0;
+ }
+ sg = sg_next(sg);
+ if (!sg)
+ /* Writing last descriptor for frame */
+ flags |= (D64_CTRL1_EOF | D64_CTRL1_IOC);
+ pdc_build_txd(pdcs, databufptr, bufcnt, flags | eot);
+ desc_w++;
+ /* Clear start of frame after first descriptor */
+ flags &= ~D64_CTRL1_SOF;
+ }
+ pdcs->txin_numd[pdcs->tx_msg_start] += desc_w;
+
+ return PDC_SUCCESS;
+}
+
+/**
+ * pdc_tx_list_final() - Initiate DMA transfer of last frame written to tx
+ * ring.
+ * @pdcs: PDC state for SPU to process the request
+ *
+ * Sets the index of the last descriptor written in both the rx and tx ring.
+ *
+ * Return: PDC_SUCCESS
+ */
+static int pdc_tx_list_final(struct pdc_state *pdcs)
+{
+ /*
+ * write barrier to ensure all register writes are complete
+ * before chip starts to process new request
+ */
+ wmb();
+ iowrite32(pdcs->rxout << 4, (void *)&pdcs->rxregs_64->ptr);
+ iowrite32(pdcs->txout << 4, (void *)&pdcs->txregs_64->ptr);
+ pdcs->pdc_requests++;
+
+ return PDC_SUCCESS;
+}
+
+/**
+ * pdc_rx_list_init() - Start a new receive descriptor list for a given PDC.
+ * @pdcs: PDC state for SPU handling request
+ * @dst_sg: scatterlist providing rx buffers for response to be returned to
+ * mailbox client
+ * @ctx: Opaque context for this request
+ *
+ * Posts a single receive descriptor to hold the metadata that precedes a
+ * response. For example, with SPU-M, the metadata is a 32-byte DMA header and
+ * an 8-byte BCM header. Moves the msg_start descriptor indexes for both tx and
+ * rx to indicate the start of a new message.
+ *
+ * Return: PDC_SUCCESS if successful
+ * < 0 if an error (e.g., rx ring is full)
+ */
+static int pdc_rx_list_init(struct pdc_state *pdcs, struct scatterlist *dst_sg,
+ void *ctx)
+{
+ u32 flags = 0;
+ u32 rx_avail;
+ u32 rx_pkt_cnt = 1; /* Adding a single rx buffer */
+ dma_addr_t daddr;
+ void *vaddr;
+
+ rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
+ pdcs->nrxpost);
+ if (unlikely(rx_pkt_cnt > rx_avail)) {
+ pdcs->rxnobuf++;
+ return -ENOSPC;
+ }
+
+ /* allocate a buffer for the dma rx status */
+ vaddr = dma_pool_zalloc(pdcs->rx_buf_pool, GFP_ATOMIC, &daddr);
+ if (!vaddr)
+ return -ENOMEM;
+
+ /*
+ * Update msg_start indexes for both tx and rx to indicate the start
+ * of a new sequence of descriptor indexes that contain the fragments
+ * of the same message.
+ */
+ pdcs->rx_msg_start = pdcs->rxout;
+ pdcs->tx_msg_start = pdcs->txout;
+
+ /* This is always the first descriptor in the receive sequence */
+ flags = D64_CTRL1_SOF;
+ pdcs->rxin_numd[pdcs->rx_msg_start] = 1;
+
+ if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
+ flags |= D64_CTRL1_EOT;
+
+ pdcs->rxp_ctx[pdcs->rxout] = ctx;
+ pdcs->dst_sg[pdcs->rxout] = dst_sg;
+ pdcs->resp_hdr[pdcs->rxout] = vaddr;
+ pdcs->resp_hdr_daddr[pdcs->rxout] = daddr;
+ pdc_build_rxd(pdcs, daddr, pdcs->pdc_resp_hdr_len, flags);
+ return PDC_SUCCESS;
+}
+
+/**
+ * pdc_rx_list_sg_add() - Add the buffers in a scatterlist to the receive
+ * descriptors for a given SPU. The caller must have already DMA mapped the
+ * scatterlist.
+ * @spu_idx: Indicates which SPU the buffers are for
+ * @sg: Scatterlist whose buffers are added to the receive ring
+ *
+ * If a receive buffer in the scatterlist is larger than PDC_DMA_BUF_MAX,
+ * multiple receive descriptors are written, each with a buffer <=
+ * PDC_DMA_BUF_MAX.
+ *
+ * Return: PDC_SUCCESS if successful
+ * < 0 otherwise (e.g., receive ring is full)
+ */
+static int pdc_rx_list_sg_add(struct pdc_state *pdcs, struct scatterlist *sg)
+{
+ u32 flags = 0;
+ u32 rx_avail;
+
+ /*
+ * Num descriptors needed. Conservatively assume we need a descriptor
+ * for every entry from our starting point in the scatterlist.
+ */
+ u32 num_desc;
+ u32 desc_w = 0; /* Number of tx descriptors written */
+ u32 bufcnt; /* Number of bytes of buffer pointed to by descriptor */
+ dma_addr_t databufptr; /* DMA address to put in descriptor */
+
+ num_desc = (u32)sg_nents(sg);
+
+ rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
+ pdcs->nrxpost);
+ if (unlikely(num_desc > rx_avail)) {
+ pdcs->rxnobuf++;
+ return -ENOSPC;
+ }
+
+ while (sg) {
+ if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
+ flags = D64_CTRL1_EOT;
+ else
+ flags = 0;
+
+ /*
+ * If sg buffer larger than PDC limit, split across
+ * multiple descriptors
+ */
+ bufcnt = sg_dma_len(sg);
+ databufptr = sg_dma_address(sg);
+ while (bufcnt > PDC_DMA_BUF_MAX) {
+ pdc_build_rxd(pdcs, databufptr, PDC_DMA_BUF_MAX, flags);
+ desc_w++;
+ bufcnt -= PDC_DMA_BUF_MAX;
+ databufptr += PDC_DMA_BUF_MAX;
+ if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
+ flags = D64_CTRL1_EOT;
+ else
+ flags = 0;
+ }
+ pdc_build_rxd(pdcs, databufptr, bufcnt, flags);
+ desc_w++;
+ sg = sg_next(sg);
+ }
+ pdcs->rxin_numd[pdcs->rx_msg_start] += desc_w;
+
+ return PDC_SUCCESS;
+}
+
+/**
+ * pdc_irq_handler() - Interrupt handler called in interrupt context.
+ * @irq: Interrupt number that has fired
+ * @cookie: PDC state for DMA engine that generated the interrupt
+ *
+ * We have to clear the device interrupt status flags here. So cache the
+ * status for later use in the thread function. Other than that, just return
+ * WAKE_THREAD to invoke the thread function.
+ *
+ * Return: IRQ_WAKE_THREAD if interrupt is ours
+ * IRQ_NONE otherwise
+ */
+static irqreturn_t pdc_irq_handler(int irq, void *cookie)
+{
+ struct pdc_state *pdcs = cookie;
+ u32 intstatus = ioread32(pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
+
+ if (intstatus & PDC_XMTINTEN_0)
+ set_bit(PDC_XMTINT_0, &pdcs->intstatus);
+ if (intstatus & PDC_RCVINTEN_0)
+ set_bit(PDC_RCVINT_0, &pdcs->intstatus);
+
+ /* Clear interrupt flags in device */
+ iowrite32(intstatus, pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
+
+ /* Wakeup IRQ thread */
+ if (pdcs && (irq == pdcs->pdc_irq) && (intstatus & PDC_INTMASK))
+ return IRQ_WAKE_THREAD;
+
+ return IRQ_NONE;
+}
+
+/**
+ * pdc_irq_thread() - Function invoked on deferred thread when a DMA tx has
+ * completed or data is available to receive.
+ * @irq: Interrupt number
+ * @cookie: PDC state for PDC that generated the interrupt
+ *
+ * On DMA tx complete, notify the mailbox client. On DMA rx complete, process
+ * as many SPU response messages as are available and send each to the mailbox
+ * client.
+ *
+ * Return: IRQ_HANDLED if we recognized and handled the interrupt
+ * IRQ_NONE otherwise
+ */
+static irqreturn_t pdc_irq_thread(int irq, void *cookie)
+{
+ struct pdc_state *pdcs = cookie;
+ struct mbox_controller *mbc;
+ struct mbox_chan *chan;
+ bool tx_int;
+ bool rx_int;
+ int rx_status;
+ struct brcm_message mssg;
+
+ tx_int = test_and_clear_bit(PDC_XMTINT_0, &pdcs->intstatus);
+ rx_int = test_and_clear_bit(PDC_RCVINT_0, &pdcs->intstatus);
+
+ if (pdcs && (tx_int || rx_int)) {
+ dev_dbg(&pdcs->pdev->dev,
+ "%s() got irq %d with tx_int %s, rx_int %s",
+ __func__, irq,
+ tx_int ? "set" : "clear", rx_int ? "set" : "clear");
+
+ mbc = &pdcs->mbc;
+ chan = &mbc->chans[0];
+
+ if (tx_int) {
+ dev_dbg(&pdcs->pdev->dev, "%s(): tx done", __func__);
+ /* only one frame in flight at a time */
+ mbox_chan_txdone(chan, PDC_SUCCESS);
+ }
+ if (rx_int) {
+ while (1) {
+ /* Could be many frames ready */
+ memset(&mssg, 0, sizeof(mssg));
+ mssg.type = BRCM_MESSAGE_SPU;
+ rx_status = pdc_receive(pdcs, &mssg);
+ if (rx_status >= 0) {
+ dev_dbg(&pdcs->pdev->dev,
+ "%s(): invoking client rx cb",
+ __func__);
+ mbox_chan_received_data(chan, &mssg);
+ } else {
+ dev_dbg(&pdcs->pdev->dev,
+ "%s(): no SPU response available",
+ __func__);
+ break;
+ }
+ }
+ }
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+/**
+ * pdc_ring_init() - Allocate DMA rings and initialize constant fields of
+ * descriptors in one ringset.
+ * @pdcs: PDC instance state
+ * @ringset: index of ringset being used
+ *
+ * Return: PDC_SUCCESS if ring initialized
+ * < 0 otherwise
+ */
+static int pdc_ring_init(struct pdc_state *pdcs, int ringset)
+{
+ int i;
+ int err = PDC_SUCCESS;
+ struct dma64 *dma_reg;
+ struct device *dev = &pdcs->pdev->dev;
+ struct pdc_ring_alloc tx;
+ struct pdc_ring_alloc rx;
+
+ /* Allocate tx ring */
+ tx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &tx.dmabase);
+ if (!tx.vbase) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ /* Allocate rx ring */
+ rx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &rx.dmabase);
+ if (!rx.vbase) {
+ err = -ENOMEM;
+ goto fail_dealloc;
+ }
+
+ dev_dbg(dev, " - base DMA addr of tx ring %#llx", tx.dmabase);
+ dev_dbg(dev, " - base virtual addr of tx ring %p", tx.vbase);
+ dev_dbg(dev, " - base DMA addr of rx ring %#llx", rx.dmabase);
+ dev_dbg(dev, " - base virtual addr of rx ring %p", rx.vbase);
+
+ /* lock after ring allocation to avoid scheduling while atomic */
+ spin_lock(&pdcs->pdc_lock);
+
+ memcpy(&pdcs->tx_ring_alloc, &tx, sizeof(tx));
+ memcpy(&pdcs->rx_ring_alloc, &rx, sizeof(rx));
+
+ pdcs->rxin = 0;
+ pdcs->rx_msg_start = 0;
+ pdcs->last_rx_curr = 0;
+ pdcs->rxout = 0;
+ pdcs->txin = 0;
+ pdcs->tx_msg_start = 0;
+ pdcs->txout = 0;
+
+ /* Set descriptor array base addresses */
+ pdcs->txd_64 = (struct dma64dd *)pdcs->tx_ring_alloc.vbase;
+ pdcs->rxd_64 = (struct dma64dd *)pdcs->rx_ring_alloc.vbase;
+
+ /* Tell device the base DMA address of each ring */
+ dma_reg = &pdcs->regs->dmaregs[ringset];
+ iowrite32(lower_32_bits(pdcs->tx_ring_alloc.dmabase),
+ (void *)&dma_reg->dmaxmt.addrlow);
+ iowrite32(upper_32_bits(pdcs->tx_ring_alloc.dmabase),
+ (void *)&dma_reg->dmaxmt.addrhigh);
+
+ iowrite32(lower_32_bits(pdcs->rx_ring_alloc.dmabase),
+ (void *)&dma_reg->dmarcv.addrlow);
+ iowrite32(upper_32_bits(pdcs->rx_ring_alloc.dmabase),
+ (void *)&dma_reg->dmarcv.addrhigh);
+
+ /* Initialize descriptors */
+ for (i = 0; i < PDC_RING_ENTRIES; i++) {
+ /* Every tx descriptor can be used for start of frame. */
+ if (i != pdcs->ntxpost) {
+ iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF,
+ (void *)&pdcs->txd_64[i].ctrl1);
+ } else {
+ /* Last descriptor in ringset. Set End of Table. */
+ iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF |
+ D64_CTRL1_EOT,
+ (void *)&pdcs->txd_64[i].ctrl1);
+ }
+
+ /* Every rx descriptor can be used for start of frame */
+ if (i != pdcs->nrxpost) {
+ iowrite32(D64_CTRL1_SOF,
+ (void *)&pdcs->rxd_64[i].ctrl1);
+ } else {
+ /* Last descriptor in ringset. Set End of Table. */
+ iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOT,
+ (void *)&pdcs->rxd_64[i].ctrl1);
+ }
+ }
+ spin_unlock(&pdcs->pdc_lock);
+ return PDC_SUCCESS;
+
+fail_dealloc:
+ dma_pool_free(pdcs->ring_pool, tx.vbase, tx.dmabase);
+done:
+ return err;
+}
+
+static void pdc_ring_free(struct pdc_state *pdcs)
+{
+ if (pdcs->tx_ring_alloc.vbase) {
+ dma_pool_free(pdcs->ring_pool, pdcs->tx_ring_alloc.vbase,
+ pdcs->tx_ring_alloc.dmabase);
+ pdcs->tx_ring_alloc.vbase = NULL;
+ }
+
+ if (pdcs->rx_ring_alloc.vbase) {
+ dma_pool_free(pdcs->ring_pool, pdcs->rx_ring_alloc.vbase,
+ pdcs->rx_ring_alloc.dmabase);
+ pdcs->rx_ring_alloc.vbase = NULL;
+ }
+}
+
+/**
+ * pdc_send_data() - mailbox send_data function
+ * @chan: The mailbox channel on which the data is sent. The channel
+ * corresponds to a DMA ringset.
+ * @data: The mailbox message to be sent. The message must be a
+ * brcm_message structure.
+ *
+ * This function is registered as the send_data function for the mailbox
+ * controller. From the destination scatterlist in the mailbox message, it
+ * creates a sequence of receive descriptors in the rx ring. From the source
+ * scatterlist, it creates a sequence of transmit descriptors in the tx ring.
+ * After creating the descriptors, it writes the rx ptr and tx ptr registers to
+ * initiate the DMA transfer.
+ *
+ * This function does the DMA map and unmap of the src and dst scatterlists in
+ * the mailbox message.
+ *
+ * Return: 0 if successful
+ * -ENOTSUPP if the mailbox message is a type this driver does not
+ * support
+ * < 0 if an error
+ */
+static int pdc_send_data(struct mbox_chan *chan, void *data)
+{
+ struct pdc_state *pdcs = chan->con_priv;
+ struct device *dev = &pdcs->pdev->dev;
+ struct brcm_message *mssg = data;
+ int err = PDC_SUCCESS;
+ int src_nent;
+ int dst_nent;
+ int nent;
+
+ if (mssg->type != BRCM_MESSAGE_SPU)
+ return -ENOTSUPP;
+
+ src_nent = sg_nents(mssg->spu.src);
+ if (src_nent) {
+ nent = dma_map_sg(dev, mssg->spu.src, src_nent, DMA_TO_DEVICE);
+ if (nent == 0)
+ return -EIO;
+ }
+
+ dst_nent = sg_nents(mssg->spu.dst);
+ if (dst_nent) {
+ nent = dma_map_sg(dev, mssg->spu.dst, dst_nent,
+ DMA_FROM_DEVICE);
+ if (nent == 0) {
+ dma_unmap_sg(dev, mssg->spu.src, src_nent,
+ DMA_TO_DEVICE);
+ return -EIO;
+ }
+ }
+
+ spin_lock(&pdcs->pdc_lock);
+
+ /* Create rx descriptors to SPU catch response */
+ err = pdc_rx_list_init(pdcs, mssg->spu.dst, mssg->ctx);
+ err |= pdc_rx_list_sg_add(pdcs, mssg->spu.dst);
+
+ /* Create tx descriptors to submit SPU request */
+ err |= pdc_tx_list_sg_add(pdcs, mssg->spu.src);
+ err |= pdc_tx_list_final(pdcs); /* initiate transfer */
+
+ spin_unlock(&pdcs->pdc_lock);
+
+ if (err)
+ dev_err(&pdcs->pdev->dev,
+ "%s failed with error %d", __func__, err);
+
+ return err;
+}
+
+static int pdc_startup(struct mbox_chan *chan)
+{
+ return pdc_ring_init(chan->con_priv, PDC_RINGSET);
+}
+
+static void pdc_shutdown(struct mbox_chan *chan)
+{
+ struct pdc_state *pdcs = chan->con_priv;
+
+ if (pdcs)
+ dev_dbg(&pdcs->pdev->dev,
+ "Shutdown mailbox channel for PDC %u", pdcs->pdc_idx);
+
+ pdc_ring_free(pdcs);
+}
+
+/**
+ * pdc_hw_init() - Use the given initialization parameters to initialize the
+ * state for one of the PDCs.
+ * @dev: device structure for PDC
+ * @pdcs: state of the PDC
+ * @parms: parameter values to set
+ */
+static
+void pdc_hw_init(struct device *dev, struct pdc_state *pdcs,
+ struct hw_init_parms *parms)
+{
+ struct dma64 *dma_reg;
+
+ int ringset = PDC_RINGSET;
+
+ dev_dbg(dev, "PDC %u initial values:", pdcs->pdc_idx);
+ dev_dbg(dev, "state structure: %p",
+ pdcs);
+ dev_dbg(dev, " - base physical addr of hw regs %#llx",
+ parms->hw_pbase);
+ dev_dbg(dev, " - base virtual addr of hw regs %p",
+ parms->hw_vbase);
+
+ /* initialize data structures */
+ pdcs->regs = (struct pdc_regs *)parms->hw_vbase;
+ pdcs->txregs_64 = (struct dma64_regs *)
+ (void *)(((u8 *)parms->hw_vbase) +
+ PDC_TXREGS_OFFSET + (sizeof(struct dma64) * ringset));
+ pdcs->rxregs_64 = (struct dma64_regs *)
+ (void *)(((u8 *)parms->hw_vbase) +
+ PDC_RXREGS_OFFSET + (sizeof(struct dma64) * ringset));
+
+ pdcs->ntxd = parms->ring_entries;
+ pdcs->nrxd = parms->ring_entries;
+ pdcs->ntxpost = parms->ring_entries - 1;
+ pdcs->nrxpost = parms->ring_entries - 1;
+ pdcs->regs->intmask = 0;
+
+ dma_reg = &pdcs->regs->dmaregs[ringset];
+ iowrite32(0, (void *)&dma_reg->dmaxmt.ptr);
+ iowrite32(0, (void *)&dma_reg->dmarcv.ptr);
+
+ iowrite32(PDC_TX_CTL, (void *)&dma_reg->dmaxmt.control);
+
+ iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),
+ (void *)&dma_reg->dmarcv.control);
+
+ if (pdcs->pdc_resp_hdr_len == PDC_SPU2_RESP_HDR_LEN)
+ iowrite32(PDC_CKSUM_CTRL,
+ pdcs->pdc_reg_vbase + PDC_CKSUM_CTRL_OFFSET);
+}
+
+/**
+ * pdc_rx_buf_pool_create() - Pool of receive buffers used to catch the metadata
+ * header returned with each response message.
+ * @dev: device structure
+ * @pdcs: PDC state structure
+ *
+ * The metadata is not returned to the mailbox client. So the PDC driver
+ * manages these buffers.
+ *
+ * Return: PDC_SUCCESS
+ * -ENOMEM if pool creation fails
+ */
+static int pdc_rx_buf_pool_create(struct device *dev, struct pdc_state *pdcs)
+{
+ pdcs->pdc_resp_hdr_len = pdcs->rx_status_len;
+ if (pdcs->use_bcm_hdr)
+ pdcs->pdc_resp_hdr_len += BCM_HDR_LEN;
+
+ pdcs->rx_buf_pool = dma_pool_create("pdc rx bufs", dev,
+ pdcs->pdc_resp_hdr_len,
+ RX_BUF_ALIGN, 0);
+ if (!pdcs->rx_buf_pool)
+ return -ENOMEM;
+
+ return PDC_SUCCESS;
+}
+
+/**
+ * pdc_interrupts_init() - Initialize the interrupt configuration for a PDC and
+ * specify a threaded IRQ handler for deferred handling of interrupts outside of
+ * interrupt context.
+ * @pdev: platform device
+ * @pdcs: PDC state
+ *
+ * Set the interrupt mask for transmit and receive done.
+ * Set the lazy interrupt frame count to generate an interrupt for just one pkt.
+ *
+ * Return: PDC_SUCCESS
+ * <0 if threaded irq request fails
+ */
+static int pdc_interrupts_init(struct platform_device *pdev,
+ struct pdc_state *pdcs)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *dn = pdev->dev.of_node;
+ int err;
+
+ pdcs->intstatus = 0;
+
+ /* interrupt configuration */
+ iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
+ iowrite32(PDC_LAZY_INT, pdcs->pdc_reg_vbase + PDC_RCVLAZY0_OFFSET);
+
+ /* read irq from device tree */
+ pdcs->pdc_irq = irq_of_parse_and_map(dn, 0);
+ dev_dbg(dev, "pdc device %s irq %u for pdcs %p",
+ dev_name(dev), pdcs->pdc_irq, pdcs);
+ err = devm_request_threaded_irq(dev, pdcs->pdc_irq,
+ pdc_irq_handler,
+ pdc_irq_thread, 0, dev_name(dev), pdcs);
+ if (err) {
+ dev_err(dev, "threaded tx IRQ %u request failed with err %d\n",
+ pdcs->pdc_irq, err);
+ return err;
+ }
+ return PDC_SUCCESS;
+}
+
+static const struct mbox_chan_ops pdc_mbox_chan_ops = {
+ .send_data = pdc_send_data,
+ .startup = pdc_startup,
+ .shutdown = pdc_shutdown
+};
+
+/**
+ * pdc_mb_init() - Initialize the mailbox controller.
+ * @pdcs: PDC state
+ *
+ * Each PDC is a mailbox controller. Each ringset is a mailbox channel. Kernel
+ * driver only uses one ringset and thus one mb channel. PDC uses the transmit
+ * complete interrupt to determine when a mailbox message has successfully been
+ * transmitted.
+ *
+ * Return: 0 on success
+ * < 0 if there is an allocation or registration failure
+ */
+static int pdc_mb_init(struct pdc_state *pdcs)
+{
+ struct device *dev = &pdcs->pdev->dev;
+ struct mbox_controller *mbc;
+ int chan_index;
+ int err;
+
+ mbc = &pdcs->mbc;
+ mbc->dev = dev;
+ mbc->ops = &pdc_mbox_chan_ops;
+ mbc->num_chans = 1;
+ mbc->chans = devm_kcalloc(dev, mbc->num_chans, sizeof(*mbc->chans),
+ GFP_KERNEL);
+ if (!mbc->chans)
+ return -ENOMEM;
+
+ mbc->txdone_irq = true;
+ mbc->txdone_poll = false;
+ for (chan_index = 0; chan_index < mbc->num_chans; chan_index++)
+ mbc->chans[chan_index].con_priv = pdcs;
+
+ /* Register mailbox controller */
+ err = mbox_controller_register(mbc);
+ if (err) {
+ dev_crit(dev,
+ "Failed to register PDC mailbox controller. Error %d.",
+ err);
+ return err;
+ }
+ return 0;
+}
+
+/**
+ * pdc_dt_read() - Read application-specific data from device tree.
+ * @pdev: Platform device
+ * @pdcs: PDC state
+ *
+ * Reads the number of bytes of receive status that precede each received frame.
+ * Reads whether transmit and received frames should be preceded by an 8-byte
+ * BCM header.
+ *
+ * Return: 0 if successful
+ * -ENODEV if device not available
+ */
+static int pdc_dt_read(struct platform_device *pdev, struct pdc_state *pdcs)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *dn = pdev->dev.of_node;
+ int err;
+
+ err = of_property_read_u32(dn, "brcm,rx-status-len",
+ &pdcs->rx_status_len);
+ if (err < 0)
+ dev_err(dev,
+ "%s failed to get DMA receive status length from device tree",
+ __func__);
+
+ pdcs->use_bcm_hdr = of_property_read_bool(dn, "brcm,use-bcm-hdr");
+
+ return 0;
+}
+
+/**
+ * pdc_probe() - Probe function for PDC driver.
+ * @pdev: PDC platform device
+ *
+ * Reserve and map register regions defined in device tree.
+ * Allocate and initialize tx and rx DMA rings.
+ * Initialize a mailbox controller for each PDC.
+ *
+ * Return: 0 if successful
+ * < 0 if an error
+ */
+static int pdc_probe(struct platform_device *pdev)
+{
+ int err = 0;
+ struct device *dev = &pdev->dev;
+ struct resource *pdc_regs;
+ struct pdc_state *pdcs;
+ struct hw_init_parms hw_parms; /* params for initializing spu-dma */
+
+ /* PDC state for one SPU */
+ pdcs = devm_kzalloc(dev, sizeof(*pdcs), GFP_KERNEL);
+ if (!pdcs) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+
+ spin_lock_init(&pdcs->pdc_lock);
+ pdcs->pdev = pdev;
+ platform_set_drvdata(pdev, pdcs);
+ pdcs->pdc_idx = pdcg.num_spu;
+ pdcg.num_spu++;
+
+ err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (err) {
+ dev_warn(dev, "PDC device cannot perform DMA. Error %d.", err);
+ goto cleanup;
+ }
+
+ /* Create DMA pool for tx ring */
+ pdcs->ring_pool = dma_pool_create("pdc rings", dev, PDC_RING_SIZE,
+ RING_ALIGN, 0);
+ if (!pdcs->ring_pool) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+
+ err = pdc_dt_read(pdev, pdcs);
+ if (err)
+ goto cleanup_ring_pool;
+
+ pdc_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!pdc_regs) {
+ err = -ENODEV;
+ goto cleanup_ring_pool;
+ }
+ dev_dbg(dev, "PDC register region res.start = %#llx, res.end = %#llx",
+ pdc_regs->start, pdc_regs->end);
+
+ pdcs->pdc_reg_vbase = devm_ioremap_resource(&pdev->dev, pdc_regs);
+ if (IS_ERR(pdcs->pdc_reg_vbase)) {
+ err = PTR_ERR(pdcs->pdc_reg_vbase);
+ dev_err(&pdev->dev, "Failed to map registers: %d\n", err);
+ goto cleanup_ring_pool;
+ }
+
+ /* create rx buffer pool after dt read to know how big buffers are */
+ err = pdc_rx_buf_pool_create(dev, pdcs);
+ if (err)
+ goto cleanup_ring_pool;
+
+ hw_parms.hw_pbase = (dma_addr_t)(pdc_regs->start);
+ hw_parms.hw_vbase = pdcs->pdc_reg_vbase;
+
+ hw_parms.ring_entries = PDC_RING_ENTRIES;
+
+ pdc_hw_init(dev, pdcs, &hw_parms);
+
+ err = pdc_interrupts_init(pdev, pdcs);
+ if (err)
+ goto cleanup_buf_pool;
+
+ /* Initialize mailbox controller */
+ err = pdc_mb_init(pdcs);
+ if (err)
+ goto cleanup_buf_pool;
+
+ pdcs->debugfs_stats = NULL;
+ pdc_setup_debugfs(pdcs);
+
+ dev_dbg(dev, "pdc_probe() successful");
+ return PDC_SUCCESS;
+
+cleanup_buf_pool:
+ dma_pool_destroy(pdcs->rx_buf_pool);
+
+cleanup_ring_pool:
+ dma_pool_destroy(pdcs->ring_pool);
+
+cleanup:
+ return err;
+}
+
+static int pdc_remove(struct platform_device *pdev)
+{
+ struct pdc_state *pdcs = platform_get_drvdata(pdev);
+
+ pdc_free_debugfs();
+
+ mbox_controller_unregister(&pdcs->mbc);
+
+ dma_pool_destroy(pdcs->rx_buf_pool);
+ dma_pool_destroy(pdcs->ring_pool);
+ return 0;
+}
+
+static const struct of_device_id pdc_mbox_of_match[] = {
+ {.compatible = "brcm,iproc-pdc-mbox"},
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pdc_mbox_of_match);
+
+static struct platform_driver pdc_mbox_driver = {
+ .probe = pdc_probe,
+ .remove = pdc_remove,
+ .driver = {
+ .name = "brcm-iproc-pdc-mbox",
+ .of_match_table = of_match_ptr(pdc_mbox_of_match),
+ },
+};
+module_platform_driver(pdc_mbox_driver);
+
+MODULE_AUTHOR("Rob Rice <rob.rice@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom PDC mailbox driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/mailbox-pdc/pdc.h b/drivers/mailbox/mailbox-pdc/pdc.h
new file mode 100644
index 0000000..17e1464
--- /dev/null
+++ b/drivers/mailbox/mailbox-pdc/pdc.h
@@ -0,0 +1,303 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation (the "GPL").
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 (GPLv2) for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 (GPLv2) along with this source code.
+ */
+#ifndef PDC_H
+#define PDC_H
+
+#include <linux/scatterlist.h>
+#include <linux/mailbox_controller.h>
+
+#define PDC_SUCCESS 0
+
+#define RING_ENTRY_SIZE sizeof(struct dma64dd)
+
+/* # entries in PDC dma ring */
+#define PDC_RING_ENTRIES 128
+#define PDC_RING_SIZE (PDC_RING_ENTRIES * RING_ENTRY_SIZE)
+/* Rings are 8k aligned */
+#define RING_ALIGN_ORDER 13
+#define RING_ALIGN BIT(RING_ALIGN_ORDER)
+
+#define RX_BUF_ALIGN_ORDER 5
+#define RX_BUF_ALIGN BIT(RX_BUF_ALIGN_ORDER)
+
+/* descriptor bumping macros */
+#define XXD(x, max_mask) ((x) & (max_mask))
+#define TXD(x, max_mask) XXD((x), (max_mask))
+#define RXD(x, max_mask) XXD((x), (max_mask))
+#define NEXTTXD(i, max_mask) TXD((i) + 1, (max_mask))
+#define PREVTXD(i, max_mask) TXD((i) - 1, (max_mask))
+#define NEXTRXD(i, max_mask) RXD((i) + 1, (max_mask))
+#define PREVRXD(i, max_mask) RXD((i) - 1, (max_mask))
+#define NTXDACTIVE(h, t, max_mask) TXD((t) - (h), (max_mask))
+#define NRXDACTIVE(h, t, max_mask) RXD((t) - (h), (max_mask))
+
+struct pdc_dma_map {
+ void *ctx; /* opaque context associated with frame */
+};
+
+struct hw_init_parms {
+ dma_addr_t hw_pbase; /* base physical addr of PDC regs */
+ void *hw_vbase; /* base virtual addr of PDC regs */
+
+ u32 ring_entries; /* number of ring entries */
+};
+
+/* dma descriptor */
+struct dma64dd {
+ u32 ctrl1; /* misc control bits */
+ u32 ctrl2; /* buffer count and address extension */
+ u32 addrlow; /* memory address of the date buffer, bits 31:0 */
+ u32 addrhigh; /* memory address of the date buffer, bits 63:32 */
+};
+
+/* dma registers per channel(xmt or rcv) */
+struct dma64_regs {
+ u32 control; /* enable, et al */
+ u32 ptr; /* last descriptor posted to chip */
+ u32 addrlow; /* descriptor ring base address low 32-bits */
+ u32 addrhigh; /* descriptor ring base address bits 63:32 */
+ u32 status0; /* last rx descriptor written by hw */
+ u32 status1; /* driver does not use */
+};
+
+/* cpp contortions to concatenate w/arg prescan */
+#ifndef PAD
+#define _PADLINE(line) pad ## line
+#define _XSTR(line) _PADLINE(line)
+#define PAD _XSTR(__LINE__)
+#endif /* PAD */
+
+/* dma registers. matches hw layout. */
+struct dma64 {
+ struct dma64_regs dmaxmt; /* dma tx */
+ u32 PAD[2];
+ struct dma64_regs dmarcv; /* dma rx */
+ u32 PAD[2];
+};
+
+/* PDC registers */
+struct pdc_regs {
+ u32 devcontrol; /* 0x000 */
+ u32 devstatus; /* 0x004 */
+ u32 PAD;
+ u32 biststatus; /* 0x00c */
+ u32 PAD[4];
+ u32 intstatus; /* 0x020 */
+ u32 intmask; /* 0x024 */
+ u32 gptimer; /* 0x028 */
+
+ u32 PAD;
+ u32 intrcvlazy_0; /* 0x030 */
+ u32 intrcvlazy_1; /* 0x034 */
+ u32 intrcvlazy_2; /* 0x038 */
+ u32 intrcvlazy_3; /* 0x03c */
+
+ u32 PAD[48];
+ u32 removed_intrecvlazy; /* 0x100 */
+ u32 flowctlthresh; /* 0x104 */
+ u32 wrrthresh; /* 0x108 */
+ u32 gmac_idle_cnt_thresh; /* 0x10c */
+
+ u32 PAD[4];
+ u32 ifioaccessaddr; /* 0x120 */
+ u32 ifioaccessbyte; /* 0x124 */
+ u32 ifioaccessdata; /* 0x128 */
+
+ u32 PAD[21];
+ u32 phyaccess; /* 0x180 */
+ u32 PAD;
+ u32 phycontrol; /* 0x188 */
+ u32 txqctl; /* 0x18c */
+ u32 rxqctl; /* 0x190 */
+ u32 gpioselect; /* 0x194 */
+ u32 gpio_output_en; /* 0x198 */
+ u32 PAD; /* 0x19c */
+ u32 txq_rxq_mem_ctl; /* 0x1a0 */
+ u32 memory_ecc_status; /* 0x1a4 */
+ u32 serdes_ctl; /* 0x1a8 */
+ u32 serdes_status0; /* 0x1ac */
+ u32 serdes_status1; /* 0x1b0 */
+ u32 PAD[11]; /* 0x1b4-1dc */
+ u32 clk_ctl_st; /* 0x1e0 */
+ u32 hw_war; /* 0x1e4 */
+ u32 pwrctl; /* 0x1e8 */
+ u32 PAD[5];
+
+#define PDC_NUM_DMA_RINGS 4
+ struct dma64 dmaregs[PDC_NUM_DMA_RINGS]; /* 0x0200 - 0x2fc */
+
+ /* more registers follow, but we don't use them */
+};
+
+/* structure for allocating/freeing DMA rings */
+struct pdc_ring_alloc {
+ dma_addr_t dmabase; /* DMA address of start of ring */
+ void *vbase; /* base kernel virtual address of ring */
+ u32 size; /* ring allocation size in bytes */
+};
+
+/* PDC state structure */
+struct pdc_state {
+ /* synchronize access to this PDC state structure */
+ spinlock_t pdc_lock;
+
+ /* Index of the PDC whose state is in this structure instance */
+ u8 pdc_idx;
+
+ /* Platform device for this PDC instance */
+ struct platform_device *pdev;
+
+ /*
+ * Each PDC instance has a mailbox controller. PDC receives request
+ * messages through mailboxes, and sends response messages through the
+ * mailbox framework.
+ */
+ struct mbox_controller mbc;
+
+ unsigned int pdc_irq;
+
+ /*
+ * Last interrupt status read from PDC device. Saved in interrupt
+ * handler so the handler can clear the interrupt in the device,
+ * and the interrupt thread called later can know which interrupt
+ * bits are active.
+ */
+ unsigned long intstatus;
+
+ /* Number of bytes of receive status prior to each rx frame */
+ u32 rx_status_len;
+ /* Whether a BCM header is prepended to each frame */
+ bool use_bcm_hdr;
+ /* Sum of length of BCM header and rx status header */
+ u32 pdc_resp_hdr_len;
+
+ /* The base virtual address of DMA hw registers */
+ void __iomem *pdc_reg_vbase;
+
+ /* Pool for allocation of DMA rings */
+ struct dma_pool *ring_pool;
+
+ /* Pool for allocation of metadata buffers for response messages */
+ struct dma_pool *rx_buf_pool;
+
+ /*
+ * The base virtual address of DMA tx/rx descriptor rings. Corresponding
+ * DMA address and size of ring allocation.
+ */
+ struct pdc_ring_alloc tx_ring_alloc;
+ struct pdc_ring_alloc rx_ring_alloc;
+
+ struct pdc_regs *regs; /* start of PDC registers */
+
+ struct dma64_regs *txregs_64; /* dma tx engine registers */
+ struct dma64_regs *rxregs_64; /* dma rx engine registers */
+
+ /*
+ * Arrays of PDC_RING_ENTRIES descriptors
+ * To use multiple ringsets, this needs to be extended
+ */
+ struct dma64dd *txd_64; /* tx descriptor ring */
+ struct dma64dd *rxd_64; /* rx descriptor ring */
+
+ /* descriptor ring sizes */
+ u32 ntxd; /* # tx descriptors */
+ u32 nrxd; /* # rx descriptors */
+ u32 nrxpost; /* # rx buffers to keep posted */
+ u32 ntxpost; /* max number of tx buffers that can be posted */
+
+ /*
+ * Index of next tx descriptor to reclaim. That is, the descriptor
+ * index of the oldest tx buffer for which the host has yet to process
+ * the corresponding response.
+ */
+ u32 txin;
+
+ /*
+ * Index of the first receive descriptor for the sequence of
+ * message fragments currently under construction. Used to build up
+ * the rxin_numd count for a message. Updated to rxout when the host
+ * starts a new sequence of rx buffers for a new message.
+ */
+ u32 tx_msg_start;
+
+ /* Index of next tx descriptor to post. */
+ u32 txout;
+
+ /*
+ * Number of tx descriptors associated with the message that starts
+ * at this tx descriptor index.
+ */
+ u32 txin_numd[PDC_RING_ENTRIES];
+
+ /*
+ * Index of next rx descriptor to reclaim. This is the index of
+ * the next descriptor whose data has yet to be processed by the host.
+ */
+ u32 rxin;
+
+ /*
+ * Index of the first receive descriptor for the sequence of
+ * message fragments currently under construction. Used to build up
+ * the rxin_numd count for a message. Updated to rxout when the host
+ * starts a new sequence of rx buffers for a new message.
+ */
+ u32 rx_msg_start;
+
+ /*
+ * Saved value of current hardware rx descriptor index.
+ * The last rx buffer written by the hw is the index previous to
+ * this one.
+ */
+ u32 last_rx_curr;
+
+ /* Index of next rx descriptor to post. */
+ u32 rxout;
+
+ /*
+ * opaque context associated with frame that starts at each
+ * rx ring index.
+ */
+ void *rxp_ctx[PDC_RING_ENTRIES];
+
+ /*
+ * Scatterlists used to form request and reply frames beginning at a
+ * given ring index. Retained in order to unmap each sg after reply
+ * is processed
+ */
+ struct scatterlist *src_sg[PDC_RING_ENTRIES];
+ struct scatterlist *dst_sg[PDC_RING_ENTRIES];
+
+ /*
+ * Number of rx descriptors associated with the message that starts
+ * at this descriptor index. Not set for every index. For example,
+ * if descriptor index i points to a scatterlist with 4 entries, then
+ * the next three descriptor indexes don't have a value set.
+ */
+ u32 rxin_numd[PDC_RING_ENTRIES];
+
+ void *resp_hdr[PDC_RING_ENTRIES];
+ dma_addr_t resp_hdr_daddr[PDC_RING_ENTRIES];
+
+ struct dentry *debugfs_stats; /* debug FS stats file for this PDC */
+
+ /* counters */
+ u32 pdc_requests; /* number of request messages submitted */
+ u32 pdc_replies; /* number of reply messages received */
+ u32 txnobuf; /* count of tx ring full */
+ u32 rxnobuf; /* count of rx ring full */
+ u32 rx_oflow; /* count of rx overflows */
+};
+#endif
diff --git a/drivers/mailbox/mailbox-pdc/pdc_debug.c b/drivers/mailbox/mailbox-pdc/pdc_debug.c
new file mode 100644
index 0000000..891a937
--- /dev/null
+++ b/drivers/mailbox/mailbox-pdc/pdc_debug.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation (the "GPL").
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 (GPLv2) for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 (GPLv2) along with this source code.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+
+#include "pdc.h"
+
+/* top level debug FS directory for PDC driver */
+static struct dentry *debugfs_dir;
+
+static ssize_t pdc_debugfs_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *offp)
+{
+ struct pdc_state *pdcs;
+ char *buf;
+ ssize_t ret, out_offset, out_count;
+
+ out_count = 512;
+
+ buf = kmalloc(out_count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ pdcs = filp->private_data;
+ out_offset = 0;
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "SPU %u stats:\n", pdcs->pdc_idx);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "PDC requests............%u\n",
+ pdcs->pdc_requests);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "PDC responses...........%u\n",
+ pdcs->pdc_replies);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Tx err ring full........%u\n",
+ pdcs->txnobuf);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Rx err ring full........%u\n",
+ pdcs->rxnobuf);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Receive overflow........%u\n",
+ pdcs->rx_oflow);
+
+ if (out_offset > out_count)
+ out_offset = out_count;
+
+ ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations pdc_debugfs_stats = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = pdc_debugfs_read,
+};
+
+/**
+ * pdc_setup_debugfs() - Create the debug FS directories. If the top-level
+ * directory has not yet been created, create it now. Create a stats file in
+ * this directory for a SPU.
+ * @pdcs: PDC state structure
+ */
+void pdc_setup_debugfs(struct pdc_state *pdcs)
+{
+ char spu_stats_name[16];
+
+ if (!debugfs_initialized())
+ return;
+
+ snprintf(spu_stats_name, 16, "pdc%d_stats", pdcs->pdc_idx);
+ if (!debugfs_dir)
+ debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+ pdcs->debugfs_stats = debugfs_create_file(spu_stats_name, S_IRUSR,
+ debugfs_dir, pdcs,
+ &pdc_debugfs_stats);
+}
+
+void pdc_free_debugfs(void)
+{
+ if (debugfs_dir && simple_empty(debugfs_dir)) {
+ debugfs_remove_recursive(debugfs_dir);
+ debugfs_dir = NULL;
+ }
+}
diff --git a/drivers/mailbox/mailbox-pdc/pdc_debug.h b/drivers/mailbox/mailbox-pdc/pdc_debug.h
new file mode 100644
index 0000000..f5120a2
--- /dev/null
+++ b/drivers/mailbox/mailbox-pdc/pdc_debug.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation (the "GPL").
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 (GPLv2) for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 (GPLv2) along with this source code.
+ */
+
+#ifndef _PDC_DEBUG_H
+#define _PDC_DEBUG_H
+
+#include "pdc.h"
+
+void pdc_setup_debugfs(struct pdc_state *pdcs);
+void pdc_free_debugfs(void);
+#endif
diff --git a/include/linux/mailbox/brcm-message.h b/include/linux/mailbox/brcm-message.h
new file mode 100644
index 0000000..6b55c93
--- /dev/null
+++ b/include/linux/mailbox/brcm-message.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Common header for Broadcom mailbox messages which is shared across
+ * Broadcom SoCs and Broadcom mailbox client drivers.
+ */
+
+#ifndef _LINUX_BRCM_MESSAGE_H_
+#define _LINUX_BRCM_MESSAGE_H_
+
+#include <linux/scatterlist.h>
+
+enum brcm_message_type {
+ BRCM_MESSAGE_UNKNOWN = 0,
+ BRCM_MESSAGE_SPU,
+ BRCM_MESSAGE_SBA,
+ BRCM_MESSAGE_MAX,
+};
+
+struct brcm_sba_command {
+ u64 cmd;
+#define BRCM_SBA_CMD_TYPE_A BIT(0)
+#define BRCM_SBA_CMD_TYPE_B BIT(1)
+#define BRCM_SBA_CMD_TYPE_C BIT(2)
+#define BRCM_SBA_CMD_HAS_RESP BIT(3)
+#define BRCM_SBA_CMD_HAS_OUTPUT BIT(4)
+ u64 flags;
+ dma_addr_t input;
+ size_t input_len;
+ dma_addr_t resp;
+ size_t resp_len;
+ dma_addr_t output;
+ size_t output_len;
+};
+
+struct brcm_message {
+ enum brcm_message_type type;
+ union {
+ struct {
+ struct scatterlist *src;
+ struct scatterlist *dst;
+ } spu;
+ struct {
+ struct brcm_sba_command *cmds;
+ unsigned int cmds_count;
+ } sba;
+ };
+ void *ctx;
+ int error;
+};
+
+#endif /* _LINUX_BRCM_MESSAGE_H_ */
--
2.1.0