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remarkable-linux/drivers/mailbox/bcm-pdc-mailbox.c
Steve Lin fc2041c541 mailbox: bcm-pdc: Add Northstar Plus support to PDC driver 
Adds support for Northstar Plus (NS+) products to the PDC mailbox
driver.  The PDC driver was originally written to support the PDC
ring manager in the Northstar2 (64-bit) device.  The NS+ (32 bit
device) uses an almost identical ring manager, though with a
different name.  We just need to check for the type of hardware in
use, in order to write the appropriate interrupt configuration register.
Also updated DMA width to be correct for both NS+ and NS2.

Tested on NS+ and NS2.

Signed-off-by: Steve Lin <steven.lin1@broadcom.com>
Acked-by: Jon Mason <jon.mason@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2017-03-28 23:27:56 +05:30

1664 lines
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/*
* 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,
* and in others the FA2/FA+ hardware is used with this PDC driver.
*
* 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/debugfs.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>
#define PDC_SUCCESS 0
#define RING_ENTRY_SIZE sizeof(struct dma64dd)
/* # entries in PDC dma ring */
#define PDC_RING_ENTRIES 512
/*
* Minimum number of ring descriptor entries that must be free to tell mailbox
* framework that it can submit another request
*/
#define PDC_RING_SPACE_MIN 15
#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))
/* 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_RCVINT_0 (16 + PDC_RINGSET)
#define PDC_RCVINTEN_0 BIT(PDC_RCVINT_0)
#define PDC_INTMASK (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)
#define FA_RCVLAZY0_OFFSET 0x100
/*
* 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:
* 11 - PtyChkDisable - parity check is disabled
* 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory
*/
#define PDC_TX_CTL 0x000C0800
/* Bit in tx control reg to enable tx channel */
#define PDC_TX_ENABLE 0x1
/*
* Sets the following bits for write to receive control reg:
* 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 0x000C0E00
/* Bit in rx control reg to enable rx channel */
#define PDC_RX_ENABLE 0x1
#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
enum pdc_hw {
FA_HW, /* FA2/FA+ hardware (i.e. Northstar Plus) */
PDC_HW /* PDC/MDE hardware (i.e. Northstar 2, Pegasus) */
};
struct pdc_dma_map {
void *ctx; /* opaque context associated with frame */
};
/* 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 (Only in PDC, not FA2) */
u32 intrcvlazy_1; /* 0x034 (Only in PDC, not FA2) */
u32 intrcvlazy_2; /* 0x038 (Only in PDC, not FA2) */
u32 intrcvlazy_3; /* 0x03c (Only in PDC, not FA2) */
u32 PAD[48];
u32 fa_intrecvlazy; /* 0x100 (Only in FA2, not PDC) */
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 (Only in PDC, not FA2) */
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 */
};
/*
* context associated with a receive descriptor.
* @rxp_ctx: opaque context associated with frame that starts at each
* rx ring index.
* @dst_sg: Scatterlist used to form reply frames beginning at a given ring
* index. Retained in order to unmap each sg after reply is processed.
* @rxin_numd: Number of rx descriptors associated with the message that starts
* at a 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.
* @resp_hdr: Virtual address of buffer used to catch DMA rx status
* @resp_hdr_daddr: physical address of DMA rx status buffer
*/
struct pdc_rx_ctx {
void *rxp_ctx;
struct scatterlist *dst_sg;
u32 rxin_numd;
void *resp_hdr;
dma_addr_t resp_hdr_daddr;
};
/* PDC state structure */
struct pdc_state {
/* 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;
/* tasklet for deferred processing after DMA rx interrupt */
struct tasklet_struct rx_tasklet;
/* 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;
struct pdc_rx_ctx rx_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 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 last_tx_not_done; /* too few tx descriptors to indicate done */
u32 tx_ring_full; /* unable to accept msg because tx ring full */
u32 rx_ring_full; /* unable to accept msg because rx ring full */
u32 txnobuf; /* unable to create tx descriptor */
u32 rxnobuf; /* unable to create rx descriptor */
u32 rx_oflow; /* count of rx overflows */
/* hardware type - FA2 or PDC/MDE */
enum pdc_hw hw_type;
};
/* Global variables */
struct pdc_globals {
/* Actual number of SPUs in hardware, as reported by device tree */
u32 num_spu;
};
static struct pdc_globals pdcg;
/* 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 not done.....................%u\n",
pdcs->last_tx_not_done);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Tx ring full....................%u\n",
pdcs->tx_ring_full);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Rx ring full....................%u\n",
pdcs->rx_ring_full);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Tx desc write fail. Ring full...%u\n",
pdcs->txnobuf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Rx desc write fail. Ring full...%u\n",
pdcs->rxnobuf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Receive overflow................%u\n",
pdcs->rx_oflow);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"Num frags in rx ring............%u\n",
NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr,
pdcs->nrxpost));
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
*/
static 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);
/* S_IRUSR == 0400 */
pdcs->debugfs_stats = debugfs_create_file(spu_stats_name, 0400,
debugfs_dir, pdcs,
&pdc_debugfs_stats);
}
static void pdc_free_debugfs(void)
{
debugfs_remove_recursive(debugfs_dir);
debugfs_dir = NULL;
}
/**
* 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;
struct dma64dd *rxd = &pdcs->rxd_64[pdcs->rxout];
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);
rxd->addrlow = cpu_to_le32(lower_32_bits(dma_addr));
rxd->addrhigh = cpu_to_le32(upper_32_bits(dma_addr));
rxd->ctrl1 = cpu_to_le32(flags);
rxd->ctrl2 = cpu_to_le32(buf_len);
/* 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;
struct dma64dd *txd = &pdcs->txd_64[pdcs->txout];
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);
txd->addrlow = cpu_to_le32(lower_32_bits(dma_addr));
txd->addrhigh = cpu_to_le32(upper_32_bits(dma_addr));
txd->ctrl1 = cpu_to_le32(flags);
txd->ctrl2 = cpu_to_le32(buf_len);
/* bump ring index and return */
pdcs->txout = NEXTTXD(pdcs->txout, pdcs->ntxpost);
}
/**
* pdc_receive_one() - Receive a response message from a given SPU.
* @pdcs: PDC state for the SPU to receive from
*
* When the return code indicates success, the response message is available in
* the receive buffers provided prior to submission of the 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_one(struct pdc_state *pdcs)
{
struct device *dev = &pdcs->pdev->dev;
struct mbox_controller *mbc;
struct mbox_chan *chan;
struct brcm_message mssg;
u32 len, rx_status;
u32 num_frags;
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;
struct pdc_rx_ctx *rx_ctx;
mbc = &pdcs->mbc;
chan = &mbc->chans[0];
mssg.type = BRCM_MESSAGE_SPU;
/*
* 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->rx_ctx[pdcs->rxin].rxin_numd))
/* No response ready */
return -EAGAIN;
num_frags = pdcs->txin_numd[pdcs->txin];
WARN_ON(num_frags == 0);
dma_unmap_sg(dev, pdcs->src_sg[pdcs->txin],
sg_nents(pdcs->src_sg[pdcs->txin]), DMA_TO_DEVICE);
pdcs->txin = (pdcs->txin + num_frags) & pdcs->ntxpost;
dev_dbg(dev, "PDC %u reclaimed %d tx descriptors",
pdcs->pdc_idx, num_frags);
rx_idx = pdcs->rxin;
rx_ctx = &pdcs->rx_ctx[rx_idx];
num_frags = rx_ctx->rxin_numd;
/* Return opaque context with result */
mssg.ctx = rx_ctx->rxp_ctx;
rx_ctx->rxp_ctx = NULL;
resp_hdr = rx_ctx->resp_hdr;
resp_hdr_daddr = rx_ctx->resp_hdr_daddr;
dma_unmap_sg(dev, rx_ctx->dst_sg, sg_nents(rx_ctx->dst_sg),
DMA_FROM_DEVICE);
pdcs->rxin = (pdcs->rxin + num_frags) & pdcs->nrxpost;
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);
mbox_chan_received_data(chan, &mssg);
pdcs->pdc_replies++;
return PDC_SUCCESS;
}
/**
* pdc_receive() - Process as many responses as are available in the rx ring.
* @pdcs: PDC state
*
* Called within the hard IRQ.
* Return:
*/
static int
pdc_receive(struct pdc_state *pdcs)
{
int rx_status;
/* read last_rx_curr from register once */
pdcs->last_rx_curr =
(ioread32(&pdcs->rxregs_64->status0) &
CRYPTO_D64_RS0_CD_MASK) / RING_ENTRY_SIZE;
do {
/* Could be many frames ready */
rx_status = pdc_receive_one(pdcs);
} while (rx_status == PDC_SUCCESS);
return 0;
}
/**
* 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, &pdcs->rxregs_64->ptr);
iowrite32(pdcs->txout << 4, &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;
struct pdc_rx_ctx *rx_ctx;
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 (unlikely(!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->rx_ctx[pdcs->rx_msg_start].rxin_numd = 1;
if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
flags |= D64_CTRL1_EOT;
rx_ctx = &pdcs->rx_ctx[pdcs->rxout];
rx_ctx->rxp_ctx = ctx;
rx_ctx->dst_sg = dst_sg;
rx_ctx->resp_hdr = vaddr;
rx_ctx->resp_hdr_daddr = 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->rx_ctx[pdcs->rx_msg_start].rxin_numd += desc_w;
return PDC_SUCCESS;
}
/**
* pdc_irq_handler() - Interrupt handler called in interrupt context.
* @irq: Interrupt number that has fired
* @data: device struct 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 *data)
{
struct device *dev = (struct device *)data;
struct pdc_state *pdcs = dev_get_drvdata(dev);
u32 intstatus = ioread32(pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
if (unlikely(intstatus == 0))
return IRQ_NONE;
/* Disable interrupts until soft handler runs */
iowrite32(0, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
/* Clear interrupt flags in device */
iowrite32(intstatus, pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
/* Wakeup IRQ thread */
tasklet_schedule(&pdcs->rx_tasklet);
return IRQ_HANDLED;
}
/**
* pdc_tasklet_cb() - Tasklet callback that runs the deferred processing after
* a DMA receive interrupt. Reenables the receive interrupt.
* @data: PDC state structure
*/
static void pdc_tasklet_cb(unsigned long data)
{
struct pdc_state *pdcs = (struct pdc_state *)data;
pdc_receive(pdcs);
/* reenable interrupts */
iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
}
/**
* 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 (unlikely(!tx.vbase)) {
err = -ENOMEM;
goto done;
}
/* Allocate rx ring */
rx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &rx.dmabase);
if (unlikely(!rx.vbase)) {
err = -ENOMEM;
goto fail_dealloc;
}
dev_dbg(dev, " - base DMA addr of tx ring %pad", &tx.dmabase);
dev_dbg(dev, " - base virtual addr of tx ring %p", tx.vbase);
dev_dbg(dev, " - base DMA addr of rx ring %pad", &rx.dmabase);
dev_dbg(dev, " - base virtual addr of rx ring %p", rx.vbase);
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];
/* But first disable DMA and set curptr to 0 for both TX & RX */
iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control);
iowrite32((PDC_RX_CTL + (pdcs->rx_status_len << 1)),
&dma_reg->dmarcv.control);
iowrite32(0, &dma_reg->dmaxmt.ptr);
iowrite32(0, &dma_reg->dmarcv.ptr);
/* Set base DMA addresses */
iowrite32(lower_32_bits(pdcs->tx_ring_alloc.dmabase),
&dma_reg->dmaxmt.addrlow);
iowrite32(upper_32_bits(pdcs->tx_ring_alloc.dmabase),
&dma_reg->dmaxmt.addrhigh);
iowrite32(lower_32_bits(pdcs->rx_ring_alloc.dmabase),
&dma_reg->dmarcv.addrlow);
iowrite32(upper_32_bits(pdcs->rx_ring_alloc.dmabase),
&dma_reg->dmarcv.addrhigh);
/* Re-enable DMA */
iowrite32(PDC_TX_CTL | PDC_TX_ENABLE, &dma_reg->dmaxmt.control);
iowrite32((PDC_RX_CTL | PDC_RX_ENABLE | (pdcs->rx_status_len << 1)),
&dma_reg->dmarcv.control);
/* 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,
&pdcs->txd_64[i].ctrl1);
} else {
/* Last descriptor in ringset. Set End of Table. */
iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF |
D64_CTRL1_EOT, &pdcs->txd_64[i].ctrl1);
}
/* Every rx descriptor can be used for start of frame */
if (i != pdcs->nrxpost) {
iowrite32(D64_CTRL1_SOF,
&pdcs->rxd_64[i].ctrl1);
} else {
/* Last descriptor in ringset. Set End of Table. */
iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOT,
&pdcs->rxd_64[i].ctrl1);
}
}
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_desc_count() - Count the number of DMA descriptors that will be required
* for a given scatterlist. Account for the max length of a DMA buffer.
* @sg: Scatterlist to be DMA'd
* Return: Number of descriptors required
*/
static u32 pdc_desc_count(struct scatterlist *sg)
{
u32 cnt = 0;
while (sg) {
cnt += ((sg->length / PDC_DMA_BUF_MAX) + 1);
sg = sg_next(sg);
}
return cnt;
}
/**
* pdc_rings_full() - Check whether the tx ring has room for tx_cnt descriptors
* and the rx ring has room for rx_cnt descriptors.
* @pdcs: PDC state
* @tx_cnt: The number of descriptors required in the tx ring
* @rx_cnt: The number of descriptors required i the rx ring
*
* Return: true if one of the rings does not have enough space
* false if sufficient space is available in both rings
*/
static bool pdc_rings_full(struct pdc_state *pdcs, int tx_cnt, int rx_cnt)
{
u32 rx_avail;
u32 tx_avail;
bool full = false;
/* Check if the tx and rx rings are likely to have enough space */
rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
pdcs->nrxpost);
if (unlikely(rx_cnt > rx_avail)) {
pdcs->rx_ring_full++;
full = true;
}
if (likely(!full)) {
tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout,
pdcs->ntxpost);
if (unlikely(tx_cnt > tx_avail)) {
pdcs->tx_ring_full++;
full = true;
}
}
return full;
}
/**
* pdc_last_tx_done() - If both the tx and rx rings have at least
* PDC_RING_SPACE_MIN descriptors available, then indicate that the mailbox
* framework can submit another message.
* @chan: mailbox channel to check
* Return: true if PDC can accept another message on this channel
*/
static bool pdc_last_tx_done(struct mbox_chan *chan)
{
struct pdc_state *pdcs = chan->con_priv;
bool ret;
if (unlikely(pdc_rings_full(pdcs, PDC_RING_SPACE_MIN,
PDC_RING_SPACE_MIN))) {
pdcs->last_tx_not_done++;
ret = false;
} else {
ret = true;
}
return ret;
}
/**
* 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;
u32 tx_desc_req;
u32 rx_desc_req;
if (unlikely(mssg->type != BRCM_MESSAGE_SPU))
return -ENOTSUPP;
src_nent = sg_nents(mssg->spu.src);
if (likely(src_nent)) {
nent = dma_map_sg(dev, mssg->spu.src, src_nent, DMA_TO_DEVICE);
if (unlikely(nent == 0))
return -EIO;
}
dst_nent = sg_nents(mssg->spu.dst);
if (likely(dst_nent)) {
nent = dma_map_sg(dev, mssg->spu.dst, dst_nent,
DMA_FROM_DEVICE);
if (unlikely(nent == 0)) {
dma_unmap_sg(dev, mssg->spu.src, src_nent,
DMA_TO_DEVICE);
return -EIO;
}
}
/*
* Check if the tx and rx rings have enough space. Do this prior to
* writing any tx or rx descriptors. Need to ensure that we do not write
* a partial set of descriptors, or write just rx descriptors but
* corresponding tx descriptors don't fit. Note that we want this check
* and the entire sequence of descriptor to happen without another
* thread getting in. The channel spin lock in the mailbox framework
* ensures this.
*/
tx_desc_req = pdc_desc_count(mssg->spu.src);
rx_desc_req = pdc_desc_count(mssg->spu.dst);
if (unlikely(pdc_rings_full(pdcs, tx_desc_req, rx_desc_req + 1)))
return -ENOSPC;
/* 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 */
if (unlikely(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)
return;
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.
* @pdcs: state of the PDC
*/
static
void pdc_hw_init(struct pdc_state *pdcs)
{
struct platform_device *pdev;
struct device *dev;
struct dma64 *dma_reg;
int ringset = PDC_RINGSET;
pdev = pdcs->pdev;
dev = &pdev->dev;
dev_dbg(dev, "PDC %u initial values:", pdcs->pdc_idx);
dev_dbg(dev, "state structure: %p",
pdcs);
dev_dbg(dev, " - base virtual addr of hw regs %p",
pdcs->pdc_reg_vbase);
/* initialize data structures */
pdcs->regs = (struct pdc_regs *)pdcs->pdc_reg_vbase;
pdcs->txregs_64 = (struct dma64_regs *)
(((u8 *)pdcs->pdc_reg_vbase) +
PDC_TXREGS_OFFSET + (sizeof(struct dma64) * ringset));
pdcs->rxregs_64 = (struct dma64_regs *)
(((u8 *)pdcs->pdc_reg_vbase) +
PDC_RXREGS_OFFSET + (sizeof(struct dma64) * ringset));
pdcs->ntxd = PDC_RING_ENTRIES;
pdcs->nrxd = PDC_RING_ENTRIES;
pdcs->ntxpost = PDC_RING_ENTRIES - 1;
pdcs->nrxpost = PDC_RING_ENTRIES - 1;
iowrite32(0, &pdcs->regs->intmask);
dma_reg = &pdcs->regs->dmaregs[ringset];
/* Configure DMA but will enable later in pdc_ring_init() */
iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control);
iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),
&dma_reg->dmarcv.control);
/* Reset current index pointers after making sure DMA is disabled */
iowrite32(0, &dma_reg->dmaxmt.ptr);
iowrite32(0, &dma_reg->dmarcv.ptr);
if (pdcs->pdc_resp_hdr_len == PDC_SPU2_RESP_HDR_LEN)
iowrite32(PDC_CKSUM_CTRL,
pdcs->pdc_reg_vbase + PDC_CKSUM_CTRL_OFFSET);
}
/**
* pdc_hw_disable() - Disable the tx and rx control in the hw.
* @pdcs: PDC state structure
*
*/
static void pdc_hw_disable(struct pdc_state *pdcs)
{
struct dma64 *dma_reg;
dma_reg = &pdcs->regs->dmaregs[PDC_RINGSET];
iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control);
iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),
&dma_reg->dmarcv.control);
}
/**
* pdc_rx_buf_pool_create() - Pool of receive buffers used to catch the metadata
* header returned with each response message.
* @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 pdc_state *pdcs)
{
struct platform_device *pdev;
struct device *dev;
pdev = pdcs->pdev;
dev = &pdev->dev;
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.
* @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 pdc_state *pdcs)
{
struct platform_device *pdev = pdcs->pdev;
struct device *dev = &pdev->dev;
struct device_node *dn = pdev->dev.of_node;
int err;
/* interrupt configuration */
iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
if (pdcs->hw_type == FA_HW)
iowrite32(PDC_LAZY_INT, pdcs->pdc_reg_vbase +
FA_RCVLAZY0_OFFSET);
else
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_irq(dev, pdcs->pdc_irq, pdc_irq_handler, 0,
dev_name(dev), dev);
if (err) {
dev_err(dev, "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,
.last_tx_done = pdc_last_tx_done,
.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 = false;
mbc->txdone_poll = true;
mbc->txpoll_period = 1;
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;
}
/* Device tree API */
static const int pdc_hw = PDC_HW;
static const int fa_hw = FA_HW;
static const struct of_device_id pdc_mbox_of_match[] = {
{.compatible = "brcm,iproc-pdc-mbox", .data = &pdc_hw},
{.compatible = "brcm,iproc-fa2-mbox", .data = &fa_hw},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, pdc_mbox_of_match);
/**
* 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;
const struct of_device_id *match;
const int *hw_type;
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");
pdcs->hw_type = PDC_HW;
match = of_match_device(of_match_ptr(pdc_mbox_of_match), dev);
if (match != NULL) {
hw_type = match->data;
pdcs->hw_type = *hw_type;
}
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;
/* PDC state for one SPU */
pdcs = devm_kzalloc(dev, sizeof(*pdcs), GFP_KERNEL);
if (!pdcs) {
err = -ENOMEM;
goto cleanup;
}
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(39));
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 = %pa, res.end = %pa",
&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(pdcs);
if (err)
goto cleanup_ring_pool;
pdc_hw_init(pdcs);
/* Init tasklet for deferred DMA rx processing */
tasklet_init(&pdcs->rx_tasklet, pdc_tasklet_cb, (unsigned long)pdcs);
err = pdc_interrupts_init(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:
tasklet_kill(&pdcs->rx_tasklet);
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();
tasklet_kill(&pdcs->rx_tasklet);
pdc_hw_disable(pdcs);
mbox_controller_unregister(&pdcs->mbc);
dma_pool_destroy(pdcs->rx_buf_pool);
dma_pool_destroy(pdcs->ring_pool);
return 0;
}
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");
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