Re: [PATCH v3 06/12] soc: aspeed: Add XDMA Engine Driver

Andrew Jeffery
2019-12-18T23:10:22Z

On Thu, 19 Dec 2019, at 01:39, Eddie James wrote:
> The XDMA engine embedded in the AST2500 and AST2600 SOCs performs PCI
> DMA operations between the SOC (acting as a BMC) and a host processor
> in a server.
>
> This commit adds a driver to control the XDMA engine and adds functions
> to initialize the hardware and memory and start DMA operations.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
> Changes since v2:
> - Remove SDRAM memory controller configuration
> - Add client_lock to protect client state
> - Rename things away from "vga"
> - Refactor set_cmd and aspeed_xdma_start a bit
> - Did various suggested cleanup items
>
> MAINTAINERS | 2 +
> drivers/soc/aspeed/Kconfig | 8 +
> drivers/soc/aspeed/Makefile | 1 +
> drivers/soc/aspeed/aspeed-xdma.c | 777 +++++++++++++++++++++++++++++++
> include/uapi/linux/aspeed-xdma.h | 38 ++
> 5 files changed, 826 insertions(+)
> create mode 100644 drivers/soc/aspeed/aspeed-xdma.c
> create mode 100644 include/uapi/linux/aspeed-xdma.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8a14d4268bdc..b72cc581c7a3 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2713,6 +2713,8 @@ M: Eddie James <eajames@linux.ibm.com>
> L: linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
> S: Maintained
> F: Documentation/devicetree/bindings/soc/aspeed/xdma.txt
> +F: drivers/soc/aspeed/aspeed-xdma.c
> +F: include/uapi/linux/aspeed-xdma.h
>
> ASUS NOTEBOOKS AND EEEPC ACPI/WMI EXTRAS DRIVERS
> M: Corentin Chary <corentin.chary@gmail.com>
> diff --git a/drivers/soc/aspeed/Kconfig b/drivers/soc/aspeed/Kconfig
> index 323e177aa74d..2a6c16f9e50b 100644
> --- a/drivers/soc/aspeed/Kconfig
> +++ b/drivers/soc/aspeed/Kconfig
> @@ -29,4 +29,12 @@ config ASPEED_P2A_CTRL
> ioctl()s, the driver also provides an interface for userspace mappings to
> a pre-defined region.
>
> +config ASPEED_XDMA
> + tristate "Aspeed XDMA Engine Driver"
> + depends on SOC_ASPEED && REGMAP && MFD_SYSCON && HAS_DMA
> + help
> + Enable support for the Aspeed XDMA Engine found on the Aspeed AST2XXX
> + SOCs. The XDMA engine can perform automatic PCI DMA operations
> + between the AST2XXX (acting as a BMC) and a host processor.
> +
> endmenu
> diff --git a/drivers/soc/aspeed/Makefile b/drivers/soc/aspeed/Makefile
> index b64be47f2b1f..977b046dfb73 100644
> --- a/drivers/soc/aspeed/Makefile
> +++ b/drivers/soc/aspeed/Makefile
> @@ -2,3 +2,4 @@
> obj-$(CONFIG_ASPEED_LPC_CTRL) += aspeed-lpc-ctrl.o
> obj-$(CONFIG_ASPEED_LPC_SNOOP) += aspeed-lpc-snoop.o
> obj-$(CONFIG_ASPEED_P2A_CTRL) += aspeed-p2a-ctrl.o
> +obj-$(CONFIG_ASPEED_XDMA) += aspeed-xdma.o
> diff --git a/drivers/soc/aspeed/aspeed-xdma.c b/drivers/soc/aspeed/aspeed-xdma.c
> new file mode 100644
> index 000000000000..cb94adf798b1
> --- /dev/null
> +++ b/drivers/soc/aspeed/aspeed-xdma.c
> @@ -0,0 +1,777 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +// Copyright IBM Corp 2019
> +
> +#include <linux/aspeed-xdma.h>
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/fs.h>
> +#include <linux/genalloc.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/jiffies.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/poll.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +#include <linux/string.h>
> +#include <linux/uaccess.h>
> +#include <linux/wait.h>
> +#include <linux/workqueue.h>
> +
> +#define DEVICE_NAME "aspeed-xdma"
> +
> +#define SCU_AST2500_PCIE_CONF 0x180
> +#define SCU_AST2600_PCIE_CONF 0xc20
> +#define SCU_PCIE_CONF_VGA_EN BIT(0)
> +#define SCU_PCIE_CONF_VGA_EN_MMIO BIT(1)
> +#define SCU_PCIE_CONF_VGA_EN_LPC BIT(2)
> +#define SCU_PCIE_CONF_VGA_EN_MSI BIT(3)
> +#define SCU_PCIE_CONF_VGA_EN_MCTP BIT(4)
> +#define SCU_PCIE_CONF_VGA_EN_IRQ BIT(5)
> +#define SCU_PCIE_CONF_VGA_EN_DMA BIT(6)
> +#define SCU_PCIE_CONF_BMC_EN BIT(8)
> +#define SCU_PCIE_CONF_BMC_EN_MMIO BIT(9)
> +#define SCU_PCIE_CONF_BMC_EN_MSI BIT(11)
> +#define SCU_PCIE_CONF_BMC_EN_MCTP BIT(12)
> +#define SCU_PCIE_CONF_BMC_EN_IRQ BIT(13)
> +#define SCU_PCIE_CONF_BMC_EN_DMA BIT(14)
> +
> +#define SCU_AST2500_BMC_CLASS_REV 0x19c
> +#define SCU_AST2600_BMC_CLASS_REV 0xc4c
> +#define SCU_BMC_CLASS_REV_XDMA 0xff000001
> +
> +#define XDMA_CMDQ_SIZE PAGE_SIZE
> +#define XDMA_NUM_CMDS \
> + (XDMA_CMDQ_SIZE / sizeof(struct aspeed_xdma_cmd))
> +
> +/* Aspeed specification requires 10ms after switching the reset line */
> +#define XDMA_RESET_TIME_MS 10
> +
> +#define XDMA_CMD_AST2500_PITCH_SHIFT 3
> +#define XDMA_CMD_AST2500_PITCH_BMC GENMASK_ULL(62, 51)
> +#define XDMA_CMD_AST2500_PITCH_HOST GENMASK_ULL(46, 35)
> +#define XDMA_CMD_AST2500_PITCH_UPSTREAM BIT_ULL(31)
> +#define XDMA_CMD_AST2500_PITCH_ADDR GENMASK_ULL(29, 4)
> +#define XDMA_CMD_AST2500_PITCH_ID BIT_ULL(0)
> +#define XDMA_CMD_AST2500_CMD_IRQ_EN BIT_ULL(31)
> +#define XDMA_CMD_AST2500_CMD_LINE_NO GENMASK_ULL(27, 16)
> +#define XDMA_CMD_AST2500_CMD_IRQ_BMC BIT_ULL(15)
> +#define XDMA_CMD_AST2500_CMD_LINE_SIZE_SHIFT 4
> +#define XDMA_CMD_AST2500_CMD_LINE_SIZE \
> + GENMASK_ULL(14, XDMA_CMD_AST2500_CMD_LINE_SIZE_SHIFT)
> +#define XDMA_CMD_AST2500_CMD_ID BIT_ULL(1)
> +
> +#define XDMA_CMD_AST2600_PITCH_BMC GENMASK_ULL(62, 48)
> +#define XDMA_CMD_AST2600_PITCH_HOST GENMASK_ULL(46, 32)
> +#define XDMA_CMD_AST2600_PITCH_ADDR GENMASK_ULL(30, 0)
> +#define XDMA_CMD_AST2600_CMD_64_EN BIT_ULL(40)
> +#define XDMA_CMD_AST2600_CMD_IRQ_BMC BIT_ULL(37)
> +#define XDMA_CMD_AST2600_CMD_IRQ_HOST BIT_ULL(36)
> +#define XDMA_CMD_AST2600_CMD_UPSTREAM BIT_ULL(32)
> +#define XDMA_CMD_AST2600_CMD_LINE_NO GENMASK_ULL(27, 16)
> +#define XDMA_CMD_AST2600_CMD_LINE_SIZE GENMASK_ULL(14, 0)
> +#define XDMA_CMD_AST2600_CMD_MULTILINE_SIZE GENMASK_ULL(14, 12)
> +
> +#define XDMA_AST2500_QUEUE_ENTRY_SIZE 4
> +#define XDMA_AST2500_HOST_CMDQ_ADDR0 0x00
> +#define XDMA_AST2500_HOST_CMDQ_ENDP 0x04
> +#define XDMA_AST2500_HOST_CMDQ_WRITEP 0x08
> +#define XDMA_AST2500_HOST_CMDQ_READP 0x0c
> +#define XDMA_AST2500_BMC_CMDQ_ADDR 0x10
> +#define XDMA_AST2500_BMC_CMDQ_ENDP 0x14
> +#define XDMA_AST2500_BMC_CMDQ_WRITEP 0x18
> +#define XDMA_AST2500_BMC_CMDQ_READP 0x1c
> +#define XDMA_BMC_CMDQ_READP_RESET 0xee882266
> +#define XDMA_AST2500_CTRL 0x20
> +#define XDMA_AST2500_CTRL_US_COMP BIT(4)
> +#define XDMA_AST2500_CTRL_DS_COMP BIT(5)
> +#define XDMA_AST2500_CTRL_DS_DIRTY BIT(6)
> +#define XDMA_AST2500_CTRL_DS_SIZE_256 BIT(17)
> +#define XDMA_AST2500_CTRL_DS_TIMEOUT BIT(28)
> +#define XDMA_AST2500_CTRL_DS_CHECK_ID BIT(29)
> +#define XDMA_AST2500_STATUS 0x24
> +#define XDMA_AST2500_STATUS_US_COMP BIT(4)
> +#define XDMA_AST2500_STATUS_DS_COMP BIT(5)
> +#define XDMA_AST2500_STATUS_DS_DIRTY BIT(6)
> +#define XDMA_AST2500_INPRG_DS_CMD1 0x38
> +#define XDMA_AST2500_INPRG_DS_CMD2 0x3c
> +#define XDMA_AST2500_INPRG_US_CMD00 0x40
> +#define XDMA_AST2500_INPRG_US_CMD01 0x44
> +#define XDMA_AST2500_INPRG_US_CMD10 0x48
> +#define XDMA_AST2500_INPRG_US_CMD11 0x4c
> +#define XDMA_AST2500_INPRG_US_CMD20 0x50
> +#define XDMA_AST2500_INPRG_US_CMD21 0x54
> +#define XDMA_AST2500_HOST_CMDQ_ADDR1 0x60
> +#define XDMA_AST2500_VGA_CMDQ_ADDR0 0x64
> +#define XDMA_AST2500_VGA_CMDQ_ENDP 0x68
> +#define XDMA_AST2500_VGA_CMDQ_WRITEP 0x6c
> +#define XDMA_AST2500_VGA_CMDQ_READP 0x70
> +#define XDMA_AST2500_VGA_CMD_STATUS 0x74
> +#define XDMA_AST2500_VGA_CMDQ_ADDR1 0x78
> +
> +#define XDMA_AST2600_QUEUE_ENTRY_SIZE 2
> +#define XDMA_AST2600_HOST_CMDQ_ADDR0 0x00
> +#define XDMA_AST2600_HOST_CMDQ_ADDR1 0x04
> +#define XDMA_AST2600_HOST_CMDQ_ENDP 0x08
> +#define XDMA_AST2600_HOST_CMDQ_WRITEP 0x0c
> +#define XDMA_AST2600_HOST_CMDQ_READP 0x10
> +#define XDMA_AST2600_BMC_CMDQ_ADDR 0x14
> +#define XDMA_AST2600_BMC_CMDQ_ENDP 0x18
> +#define XDMA_AST2600_BMC_CMDQ_WRITEP 0x1c
> +#define XDMA_AST2600_BMC_CMDQ_READP 0x20
> +#define XDMA_AST2600_VGA_CMDQ_ADDR0 0x24
> +#define XDMA_AST2600_VGA_CMDQ_ADDR1 0x28
> +#define XDMA_AST2600_VGA_CMDQ_ENDP 0x2c
> +#define XDMA_AST2600_VGA_CMDQ_WRITEP 0x30
> +#define XDMA_AST2600_VGA_CMDQ_READP 0x34
> +#define XDMA_AST2600_CTRL 0x38
> +#define XDMA_AST2600_CTRL_US_COMP BIT(16)
> +#define XDMA_AST2600_CTRL_DS_COMP BIT(17)
> +#define XDMA_AST2600_CTRL_DS_DIRTY BIT(18)
> +#define XDMA_AST2600_CTRL_DS_SIZE_256 BIT(20)
> +#define XDMA_AST2600_STATUS 0x3c
> +#define XDMA_AST2600_STATUS_US_COMP BIT(16)
> +#define XDMA_AST2600_STATUS_DS_COMP BIT(17)
> +#define XDMA_AST2600_STATUS_DS_DIRTY BIT(18)
> +#define XDMA_AST2600_INPRG_DS_CMD00 0x40
> +#define XDMA_AST2600_INPRG_DS_CMD01 0x44
> +#define XDMA_AST2600_INPRG_DS_CMD10 0x48
> +#define XDMA_AST2600_INPRG_DS_CMD11 0x4c
> +#define XDMA_AST2600_INPRG_DS_CMD20 0x50
> +#define XDMA_AST2600_INPRG_DS_CMD21 0x54
> +#define XDMA_AST2600_INPRG_US_CMD00 0x60
> +#define XDMA_AST2600_INPRG_US_CMD01 0x64
> +#define XDMA_AST2600_INPRG_US_CMD10 0x68
> +#define XDMA_AST2600_INPRG_US_CMD11 0x6c
> +#define XDMA_AST2600_INPRG_US_CMD20 0x70
> +#define XDMA_AST2600_INPRG_US_CMD21 0x74
> +
> +struct aspeed_xdma_cmd {
> + u64 host_addr;
> + u64 pitch;
> + u64 cmd;
> + u64 reserved;
> +};
> +
> +struct aspeed_xdma_regs {
> + u8 bmc_cmdq_addr;
> + u8 bmc_cmdq_endp;
> + u8 bmc_cmdq_writep;
> + u8 bmc_cmdq_readp;
> + u8 control;
> + u8 status;
> +};
> +
> +struct aspeed_xdma_status_bits {
> + u32 us_comp;
> + u32 ds_comp;
> + u32 ds_dirty;
> +};
> +
> +struct aspeed_xdma;
> +
> +struct aspeed_xdma_chip {
> + u32 control;
> + u32 scu_bmc_class;
> + u32 scu_pcie_conf;
> + unsigned int queue_entry_size;
> + struct aspeed_xdma_regs regs;
> + struct aspeed_xdma_status_bits status_bits;
> + unsigned int (*set_cmd)(struct aspeed_xdma *ctx,
> + struct aspeed_xdma_cmd *cmds,

You could (should) declare cmds as `struct aspeed_xdma_cmd cmds[2]` - this
makes it easier to validate assumptions in the code below.

> + struct aspeed_xdma_op *op, u32 bmc_addr);
> +};
> +
> +struct aspeed_xdma_client;
> +
> +struct aspeed_xdma {
> + const struct aspeed_xdma_chip *chip;
> +
> + struct device *dev;
> + void __iomem *base;
> + struct clk *clock;
> + struct reset_control *reset;
> +
> + /* client_lock protects error and in_progress of the client */
> + spinlock_t client_lock;
> + struct aspeed_xdma_client *current_client;
> +
> + /* start_lock protects cmd_idx, cmdq, and the state of the engine */
> + struct mutex start_lock;
> + struct aspeed_xdma_cmd *cmdq;
> + bool upstream;
> + unsigned int cmd_idx;
> +
> + /* reset_lock protects in_reset and the reset state of the engine */
> + spinlock_t reset_lock;
> + bool in_reset;
> +
> + wait_queue_head_t wait;
> + struct work_struct reset_work;
> +
> + u32 mem_phys;
> + u32 mem_size;
> + void __iomem *mem_virt;
> + dma_addr_t cmdq_phys;
> + struct gen_pool *pool;
> +};
> +
> +struct aspeed_xdma_client {
> + struct aspeed_xdma *ctx;
> +
> + bool error;
> + bool in_progress;
> + void *virt;
> + dma_addr_t phys;
> + u32 size;
> +};
> +
> +static u32 aspeed_xdma_readl(struct aspeed_xdma *ctx, u8 reg)
> +{
> + u32 v = readl(ctx->base + reg);
> +
> + dev_dbg(ctx->dev, "read %02x[%08x]\n", reg, v);
> + return v;
> +}
> +
> +static void aspeed_xdma_writel(struct aspeed_xdma *ctx, u8 reg, u32 val)
> +{
> + writel(val, ctx->base + reg);
> + dev_dbg(ctx->dev, "write %02x[%08x]\n", reg, val);
> +}
> +
> +static void aspeed_xdma_init_eng(struct aspeed_xdma *ctx)
> +{
> + aspeed_xdma_writel(ctx, ctx->chip->regs.bmc_cmdq_endp,
> + ctx->chip->queue_entry_size * XDMA_NUM_CMDS);
> + aspeed_xdma_writel(ctx, ctx->chip->regs.bmc_cmdq_readp,
> + XDMA_BMC_CMDQ_READP_RESET);
> + aspeed_xdma_writel(ctx, ctx->chip->regs.bmc_cmdq_writep, 0);
> + aspeed_xdma_writel(ctx, ctx->chip->regs.control, ctx->chip->control);
> + aspeed_xdma_writel(ctx, ctx->chip->regs.bmc_cmdq_addr, ctx->cmdq_phys);
> +
> + ctx->cmd_idx = 0;
> + ctx->current_client = NULL;
> +}
> +
> +static unsigned int aspeed_xdma_ast2500_set_cmd(struct aspeed_xdma *ctx,
> + struct aspeed_xdma_cmd *cmds,
> + struct aspeed_xdma_op *op,
> + u32 bmc_addr)
> +{
> + unsigned int rc = 1;
> + unsigned int pitch = 1;
> + unsigned int line_no = 1;
> + unsigned int line_size = op->len >>
> + XDMA_CMD_AST2500_CMD_LINE_SIZE_SHIFT;
> + u64 cmd = XDMA_CMD_AST2500_CMD_IRQ_EN | XDMA_CMD_AST2500_CMD_IRQ_BMC |
> + XDMA_CMD_AST2500_CMD_ID;
> + u64 cmd_pitch = (op->direction ? XDMA_CMD_AST2500_PITCH_UPSTREAM : 0) |
> + XDMA_CMD_AST2500_PITCH_ID;
> +
> + dev_dbg(ctx->dev, "xdma %s ast2500: bmc[%08x] len[%08x] host[%08x]\n",
> + op->direction ? "upstream" : "downstream", bmc_addr, op->len,
> + (u32)op->host_addr);
> +
> + if (op->len > XDMA_CMD_AST2500_CMD_LINE_SIZE) {
> + unsigned int rem;
> + unsigned int total;
> +
> + line_no = op->len / XDMA_CMD_AST2500_CMD_LINE_SIZE;
> + total = XDMA_CMD_AST2500_CMD_LINE_SIZE * line_no;
> + rem = (op->len - total) >>
> + XDMA_CMD_AST2500_CMD_LINE_SIZE_SHIFT;
> + line_size = XDMA_CMD_AST2500_CMD_LINE_SIZE;
> + pitch = line_size >> XDMA_CMD_AST2500_PITCH_SHIFT;
> + line_size >>= XDMA_CMD_AST2500_CMD_LINE_SIZE_SHIFT;
> +
> + if (rem) {
> + u32 rbmc = bmc_addr + total;
> +
> + cmds[1].host_addr = op->host_addr + (u64)total;

Here is when it becomes easier to validate the behaviour of the code wrt the cmds
declaration I mentioned above. I read this and my first question was "how do we
know that cmds[1] is valid memory?" The nice thing about declaring it in the way I
suggest is that the compiler will enforce correctness for us.

> + cmds[1].pitch = cmd_pitch |
> + ((u64)rbmc & XDMA_CMD_AST2500_PITCH_ADDR) |
> + FIELD_PREP(XDMA_CMD_AST2500_PITCH_HOST, 1) |
> + FIELD_PREP(XDMA_CMD_AST2500_PITCH_BMC, 1);
> + cmds[1].cmd = cmd |
> + FIELD_PREP(XDMA_CMD_AST2500_CMD_LINE_NO, 1) |
> + FIELD_PREP(XDMA_CMD_AST2500_CMD_LINE_SIZE,
> + rem);
> + cmds[1].reserved = 0ULL;
> +
> + print_hex_dump_debug("xdma rem ", DUMP_PREFIX_OFFSET,
> + 16, 1, &cmds[1], sizeof(*cmds),
> + true);
> +
> + cmd &= ~(XDMA_CMD_AST2500_CMD_IRQ_EN |
> + XDMA_CMD_AST2500_CMD_IRQ_BMC);
> +
> + rc++;
> + }
> + }
> +
> + cmds[0].host_addr = op->host_addr;
> + cmds[0].pitch = cmd_pitch |
> + ((u64)bmc_addr & XDMA_CMD_AST2500_PITCH_ADDR) |
> + FIELD_PREP(XDMA_CMD_AST2500_PITCH_HOST, pitch) |
> + FIELD_PREP(XDMA_CMD_AST2500_PITCH_BMC, pitch);
> + cmds[0].cmd = cmd | FIELD_PREP(XDMA_CMD_AST2500_CMD_LINE_NO, line_no) |
> + FIELD_PREP(XDMA_CMD_AST2500_CMD_LINE_SIZE, line_size);
> + cmds[0].reserved = 0ULL;
> +
> + print_hex_dump_debug("xdma cmd ", DUMP_PREFIX_OFFSET, 16, 1, cmds,
> + sizeof(*cmds), true);
> +
> + return rc;
> +}
> +
> +static unsigned int aspeed_xdma_ast2600_set_cmd(struct aspeed_xdma *ctx,
> + struct aspeed_xdma_cmd *cmds,
> + struct aspeed_xdma_op *op,
> + u32 bmc_addr)
> +{
> + unsigned int rc = 1;
> + unsigned int pitch = 1;
> + unsigned int line_no = 1;
> + unsigned int line_size = op->len;
> + u64 cmd = XDMA_CMD_AST2600_CMD_IRQ_BMC |
> + (op->direction ? XDMA_CMD_AST2600_CMD_UPSTREAM : 0);
> +
> + if (op->host_addr & 0xffffffff00000000ULL ||
> + (op->host_addr + (u64)op->len) & 0xffffffff00000000ULL)
> + cmd |= XDMA_CMD_AST2600_CMD_64_EN;
> +
> + dev_dbg(ctx->dev, "xdma %s ast2600: bmc[%08x] len[%08x] "
> + "host[%016llx]\n", op->direction ? "upstream" : "downstream",
> + bmc_addr, op->len, op->host_addr);
> +
> + if (op->len > XDMA_CMD_AST2600_CMD_LINE_SIZE) {
> + unsigned int rem;
> + unsigned int total;
> +
> + line_no = op->len / XDMA_CMD_AST2600_CMD_MULTILINE_SIZE;
> + total = XDMA_CMD_AST2600_CMD_MULTILINE_SIZE * line_no;
> + rem = op->len - total;
> + line_size = XDMA_CMD_AST2600_CMD_MULTILINE_SIZE;
> + pitch = line_size;
> +
> + if (rem) {
> + u32 rbmc = bmc_addr + total;
> +
> + cmds[1].host_addr = op->host_addr + (u64)total;
> + cmds[1].pitch =
> + ((u64)rbmc & XDMA_CMD_AST2600_PITCH_ADDR) |
> + FIELD_PREP(XDMA_CMD_AST2600_PITCH_HOST, 1) |
> + FIELD_PREP(XDMA_CMD_AST2600_PITCH_BMC, 1);
> + cmds[1].cmd = cmd |
> + FIELD_PREP(XDMA_CMD_AST2600_CMD_LINE_NO, 1) |
> + FIELD_PREP(XDMA_CMD_AST2600_CMD_LINE_SIZE,
> + rem);
> + cmds[1].reserved = 0ULL;
> +
> + print_hex_dump_debug("xdma rem ", DUMP_PREFIX_OFFSET,
> + 16, 1, &cmds[1], sizeof(*cmds),
> + true);
> +
> + cmd &= ~XDMA_CMD_AST2600_CMD_IRQ_BMC;
> +
> + rc++;
> + }
> + }
> +
> + cmds[0].host_addr = op->host_addr;
> + cmds[0].pitch = ((u64)bmc_addr & XDMA_CMD_AST2600_PITCH_ADDR) |
> + FIELD_PREP(XDMA_CMD_AST2600_PITCH_HOST, pitch) |
> + FIELD_PREP(XDMA_CMD_AST2600_PITCH_BMC, pitch);
> + cmds[0].cmd = cmd | FIELD_PREP(XDMA_CMD_AST2600_CMD_LINE_NO, line_no) |
> + FIELD_PREP(XDMA_CMD_AST2600_CMD_LINE_SIZE, line_size);
> + cmds[0].reserved = 0ULL;
> +
> + print_hex_dump_debug("xdma cmd ", DUMP_PREFIX_OFFSET, 16, 1, cmds,
> + sizeof(*cmds), true);
> +
> + return rc;
> +}
> +
> +static void aspeed_xdma_start(struct aspeed_xdma *ctx,
> + struct aspeed_xdma_op *op, u32 bmc_addr,
> + struct aspeed_xdma_client *client)
> +{
> + unsigned long flags;
> + struct aspeed_xdma_cmd cmds[2];
> + unsigned int rc = ctx->chip->set_cmd(ctx, cmds, op, bmc_addr);
> +
> + mutex_lock(&ctx->start_lock);
> +
> + memcpy(&ctx->cmdq[ctx->cmd_idx], cmds,
> + rc * sizeof(struct aspeed_xdma_cmd));
> + ctx->cmd_idx = (ctx->cmd_idx + rc) % XDMA_NUM_CMDS;
> + ctx->upstream = !!op->direction;
> +
> + spin_lock_irqsave(&ctx->client_lock, flags);
> +
> + client->error = false;
> + client->in_progress = true;
> + ctx->current_client = client;
> +
> + spin_unlock_irqrestore(&ctx->client_lock, flags);
> +
> + aspeed_xdma_writel(ctx, ctx->chip->regs.bmc_cmdq_writep,
> + ctx->cmd_idx * ctx->chip->queue_entry_size);
> +
> + mutex_unlock(&ctx->start_lock);
> +}
> +
> +static void aspeed_xdma_done(struct aspeed_xdma *ctx, bool error)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&ctx->client_lock, flags);
> +
> + if (ctx->current_client) {
> + ctx->current_client->error = error;
> + ctx->current_client->in_progress = false;
> + ctx->current_client = NULL;
> + }
> +
> + spin_unlock_irqrestore(&ctx->client_lock, flags);
> +
> + wake_up_interruptible_all(&ctx->wait);
> +}
> +
> +static irqreturn_t aspeed_xdma_irq(int irq, void *arg)
> +{
> + struct aspeed_xdma *ctx = arg;
> + u32 status = aspeed_xdma_readl(ctx, ctx->chip->regs.status);
> +
> + if (status & ctx->chip->status_bits.ds_dirty) {
> + aspeed_xdma_done(ctx, true);
> + } else {
> + if (status & ctx->chip->status_bits.us_comp) {
> + if (ctx->upstream)
> + aspeed_xdma_done(ctx, false);
> + }
> +
> + if (status & ctx->chip->status_bits.ds_comp) {
> + if (!ctx->upstream)
> + aspeed_xdma_done(ctx, false);
> + }
> + }
> +
> + aspeed_xdma_writel(ctx, ctx->chip->regs.status, status);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void aspeed_xdma_reset(struct aspeed_xdma *ctx)
> +{
> + reset_control_assert(ctx->reset);
> + msleep(XDMA_RESET_TIME_MS);
> +
> + reset_control_deassert(ctx->reset);
> + msleep(XDMA_RESET_TIME_MS);
> +
> + aspeed_xdma_init_eng(ctx);
> +

unsigned long flags;

spin_lock_irqsave(&ctx->reset_lock, flags);

> + ctx->in_reset = false;

spin_unlock_irqrestore(&ctx->reset_lock, flags);

> + aspeed_xdma_done(ctx, true);
> +}
> +
> +static void aspeed_xdma_reset_work(struct work_struct *work)
> +{
> + struct aspeed_xdma *ctx = container_of(work, struct aspeed_xdma,
> + reset_work);
> +
> + /*
> + * Lock to make sure operations aren't started while the engine is
> + * in reset.
> + */
> + mutex_lock(&ctx->start_lock);
> +
> + aspeed_xdma_reset(ctx);
> +
> + mutex_unlock(&ctx->start_lock);
> +}
> +
> +static irqreturn_t aspeed_xdma_pcie_irq(int irq, void *arg)
> +{
> + unsigned long flags;
> + struct aspeed_xdma *ctx = arg;
> +
> + dev_dbg(ctx->dev, "pcie reset\n");
> +
> + spin_lock_irqsave(&ctx->reset_lock, flags);
> + if (ctx->in_reset) {
> + spin_unlock_irqrestore(&ctx->reset_lock, flags);
> + return IRQ_HANDLED;
> + }
> +
> + ctx->in_reset = true;
> + spin_unlock_irqrestore(&ctx->reset_lock, flags);
> +
> + schedule_work(&ctx->reset_work);
> + return IRQ_HANDLED;
> +}
> +
> +static int aspeed_xdma_probe(struct platform_device *pdev)
> +{
> + int rc;
> + int irq;
> + int pcie_irq;
> + u32 memory[2];
> + struct regmap *scu;
> + struct aspeed_xdma *ctx;
> + struct device *dev = &pdev->dev;
> + const void *md = of_device_get_match_data(dev);
> +
> + if (!md)
> + return -ENODEV;
> +
> + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> + if (!ctx)
> + return -ENOMEM;
> +
> + ctx->chip = md;
> + ctx->dev = dev;
> + platform_set_drvdata(pdev, ctx);
> + mutex_init(&ctx->start_lock);
> + INIT_WORK(&ctx->reset_work, aspeed_xdma_reset_work);
> + spin_lock_init(&ctx->client_lock);
> + spin_lock_init(&ctx->reset_lock);
> + init_waitqueue_head(&ctx->wait);
> +
> + ctx->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(ctx->base)) {
> + dev_err(dev, "Failed to map registers.\n");
> + return PTR_ERR(ctx->base);
> + }
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(dev, "Unable to find IRQ.\n");
> + return irq;
> + }
> +
> + rc = devm_request_irq(dev, irq, aspeed_xdma_irq, IRQF_SHARED,

We don't need IRQF_SHARED as far as I can see.

> + DEVICE_NAME, ctx);
> + if (rc < 0) {
> + dev_err(dev, "Failed to request IRQ %d.\n", irq);
> + return rc;
> + }
> +
> + ctx->clock = devm_clk_get(dev, NULL);
> + if (IS_ERR(ctx->clock)) {
> + dev_err(dev, "Failed to request clock.\n");
> + return PTR_ERR(ctx->clock);
> + }
> +
> + ctx->reset = devm_reset_control_get_exclusive(dev, NULL);
> + if (IS_ERR(ctx->reset)) {
> + dev_err(dev, "Failed to request reset control.\n");
> + return PTR_ERR(ctx->reset);
> + }
> +
> + ctx->pool = devm_gen_pool_create(dev, ilog2(PAGE_SIZE), -1, NULL);
> + if (!ctx->pool) {
> + dev_err(dev, "Failed to setup genalloc pool.\n");
> + return -ENOMEM;
> + }
> +
> + rc = of_property_read_u32_array(dev->of_node, "memory", memory, 2);

See comment on the binding about switching to a reserved memory phandle.

> + if (rc) {
> + dev_err(dev, "Unable to get memory space.\n");
> + return rc;
> + }
> +
> + ctx->mem_phys = memory[0];
> + ctx->mem_size = memory[1];
> +
> + ctx->mem_virt = devm_ioremap(dev, ctx->mem_phys, ctx->mem_size);
> + if (IS_ERR(ctx->mem_virt)) {
> + dev_err(dev, "Failed to map memory space.\n");
> + return PTR_ERR(ctx->mem_virt);
> + }
> +
> + rc = gen_pool_add_virt(ctx->pool, (unsigned long)ctx->mem_virt,
> + ctx->mem_phys, ctx->mem_size, -1);
> + if (rc) {
> + dev_err(ctx->dev, "Failed to add memory to genalloc pool.\n");
> + return rc;
> + }
> +
> + scu = syscon_regmap_lookup_by_phandle(dev->of_node, "scu");
> + if (!IS_ERR(scu)) {
> + u32 selection;
> + bool pcie_device_bmc = true;
> + const u32 bmc = SCU_PCIE_CONF_BMC_EN |
> + SCU_PCIE_CONF_BMC_EN_MSI | SCU_PCIE_CONF_BMC_EN_IRQ |
> + SCU_PCIE_CONF_BMC_EN_DMA;
> + const u32 vga = SCU_PCIE_CONF_VGA_EN |
> + SCU_PCIE_CONF_VGA_EN_MSI | SCU_PCIE_CONF_VGA_EN_IRQ |
> + SCU_PCIE_CONF_VGA_EN_DMA;
> + const char *pcie = NULL;
> +
> + if (!of_property_read_string(dev->of_node, "pcie-device",
> + &pcie)) {
> + if (!strcmp(pcie, "vga")) {
> + pcie_device_bmc = false;
> + } else if (strcmp(pcie, "bmc")) {
> + dev_err(ctx->dev,
> + "Invalid pcie-device property %s.\n",
> + pcie);
> + return -EINVAL;
> + }
> + }
> +
> + if (pcie_device_bmc) {
> + selection = bmc;
> + regmap_write(scu, ctx->chip->scu_bmc_class,
> + SCU_BMC_CLASS_REV_XDMA);
> + } else {
> + selection = vga;
> + }
> +
> + regmap_update_bits(scu, ctx->chip->scu_pcie_conf, bmc | vga,
> + selection);
> + } else {
> + dev_warn(dev, "Unable to configure PCIe; continuing.\n");
> + }

Bit of a nit, but I think probe would be more readable if we moved the above
out to a helper function.

Looking good though!

Andrew