From 82c3a0b7f0cb97445eeb8b91b0a37d95f8c2c2a9 Mon Sep 17 00:00:00 2001 From: Liming Sun Date: Tue, 11 Apr 2023 11:39:42 -0400 Subject: [PATCH] mlxbf-bootctl: Add sysfs file for BlueField boot fifo This commit adds sysfs file for BlueField boot fifo. The boot fifo is usually used to push boot stream via USB or PCIe. Once OS is up, it can be reused by applications to read data or configuration from external host. Signed-off-by: Liming Sun Reviewed-by: David Thompson Link: https://lore.kernel.org/r/52b0b00dacbc4aad3169dd3667d79c85e334783b.1680657571.git.limings@nvidia.com Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- .../ABI/testing/sysfs-platform-mellanox-bootctl | 7 +++ drivers/platform/mellanox/mlxbf-bootctl.c | 68 ++++++++++++++++++++++ 2 files changed, 75 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl b/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl index e79ca22..9b99a81b 100644 --- a/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl +++ b/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl @@ -68,3 +68,10 @@ Description: Wasted burnt and invalid Invalid not burnt but marked as valid (error state). ======= =============================================== + +What: /sys/bus/platform/devices/MLNXBF04:00/bootfifo +Date: Apr 2023 +KernelVersion: 6.4 +Contact: "Liming Sun " +Description: + The file used to access the BlueField boot fifo. diff --git a/drivers/platform/mellanox/mlxbf-bootctl.c b/drivers/platform/mellanox/mlxbf-bootctl.c index 5e41c27..1bad1d2 100644 --- a/drivers/platform/mellanox/mlxbf-bootctl.c +++ b/drivers/platform/mellanox/mlxbf-bootctl.c @@ -10,6 +10,7 @@ #include #include +#include #include #include @@ -44,6 +45,10 @@ static const char * const mlxbf_bootctl_lifecycle_states[] = { [3] = "RMA", }; +/* Mapped pointer for RSH_BOOT_FIFO_DATA and RSH_BOOT_FIFO_COUNT register. */ +static void __iomem *mlxbf_rsh_boot_data; +static void __iomem *mlxbf_rsh_boot_cnt; + /* ARM SMC call which is atomic and no need for lock. */ static int mlxbf_bootctl_smc(unsigned int smc_op, int smc_arg) { @@ -287,6 +292,45 @@ static const struct acpi_device_id mlxbf_bootctl_acpi_ids[] = { MODULE_DEVICE_TABLE(acpi, mlxbf_bootctl_acpi_ids); +static ssize_t mlxbf_bootctl_bootfifo_read(struct file *filp, + struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, + size_t count) +{ + unsigned long timeout = msecs_to_jiffies(500); + unsigned long expire = jiffies + timeout; + u64 data, cnt = 0; + char *p = buf; + + while (count >= sizeof(data)) { + /* Give up reading if no more data within 500ms. */ + if (!cnt) { + cnt = readq(mlxbf_rsh_boot_cnt); + if (!cnt) { + if (time_after(jiffies, expire)) + break; + usleep_range(10, 50); + continue; + } + } + + data = readq(mlxbf_rsh_boot_data); + memcpy(p, &data, sizeof(data)); + count -= sizeof(data); + p += sizeof(data); + cnt--; + expire = jiffies + timeout; + } + + return p - buf; +} + +static struct bin_attribute mlxbf_bootctl_bootfifo_sysfs_attr = { + .attr = { .name = "bootfifo", .mode = 0400 }, + .read = mlxbf_bootctl_bootfifo_read, +}; + static bool mlxbf_bootctl_guid_match(const guid_t *guid, const struct arm_smccc_res *res) { @@ -304,6 +348,16 @@ static int mlxbf_bootctl_probe(struct platform_device *pdev) guid_t guid; int ret; + /* Get the resource of the bootfifo data register. */ + mlxbf_rsh_boot_data = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(mlxbf_rsh_boot_data)) + return PTR_ERR(mlxbf_rsh_boot_data); + + /* Get the resource of the bootfifo counter register. */ + mlxbf_rsh_boot_cnt = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(mlxbf_rsh_boot_cnt)) + return PTR_ERR(mlxbf_rsh_boot_cnt); + /* Ensure we have the UUID we expect for this service. */ arm_smccc_smc(MLXBF_BOOTCTL_SIP_SVC_UID, 0, 0, 0, 0, 0, 0, 0, &res); guid_parse(mlxbf_bootctl_svc_uuid_str, &guid); @@ -321,11 +375,25 @@ static int mlxbf_bootctl_probe(struct platform_device *pdev) if (ret < 0) dev_warn(&pdev->dev, "Unable to reset the EMMC boot mode\n"); + ret = sysfs_create_bin_file(&pdev->dev.kobj, + &mlxbf_bootctl_bootfifo_sysfs_attr); + if (ret) + pr_err("Unable to create bootfifo sysfs file, error %d\n", ret); + + return ret; +} + +static int mlxbf_bootctl_remove(struct platform_device *pdev) +{ + sysfs_remove_bin_file(&pdev->dev.kobj, + &mlxbf_bootctl_bootfifo_sysfs_attr); + return 0; } static struct platform_driver mlxbf_bootctl_driver = { .probe = mlxbf_bootctl_probe, + .remove = mlxbf_bootctl_remove, .driver = { .name = "mlxbf-bootctl", .dev_groups = mlxbf_bootctl_groups, -- 2.7.4