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![Qiushi Wu](/assets/img/avatar_default.png)
kobject_init_and_add() takes reference even when it fails. If this function returns an error, kobject_put() must be called to properly clean up the memory associated with the object. Callback function fw_cfg_sysfs_release_entry() in kobject_put() can handle the pointer "entry" properly. Signed-off-by: Qiushi Wu <wu000273@umn.edu> Link: https://lore.kernel.org/r/20200613190533.15712-1-wu000273@umn.edu Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
941 lines
25 KiB
C
941 lines
25 KiB
C
/*
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* drivers/firmware/qemu_fw_cfg.c
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*
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* Copyright 2015 Carnegie Mellon University
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*
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* Expose entries from QEMU's firmware configuration (fw_cfg) device in
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* sysfs (read-only, under "/sys/firmware/qemu_fw_cfg/...").
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*
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* The fw_cfg device may be instantiated via either an ACPI node (on x86
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* and select subsets of aarch64), a Device Tree node (on arm), or using
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* a kernel module (or command line) parameter with the following syntax:
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*
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* [qemu_fw_cfg.]ioport=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]
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* or
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* [qemu_fw_cfg.]mmio=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]
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*
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* where:
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* <size> := size of ioport or mmio range
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* <base> := physical base address of ioport or mmio range
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* <ctrl_off> := (optional) offset of control register
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* <data_off> := (optional) offset of data register
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* <dma_off> := (optional) offset of dma register
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*
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* e.g.:
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* qemu_fw_cfg.ioport=12@0x510:0:1:4 (the default on x86)
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* or
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* qemu_fw_cfg.mmio=16@0x9020000:8:0:16 (the default on arm)
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*/
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/platform_device.h>
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#include <linux/acpi.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/ioport.h>
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#include <uapi/linux/qemu_fw_cfg.h>
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#include <linux/delay.h>
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#include <linux/crash_dump.h>
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#include <linux/crash_core.h>
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MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>");
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MODULE_DESCRIPTION("QEMU fw_cfg sysfs support");
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MODULE_LICENSE("GPL");
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/* fw_cfg revision attribute, in /sys/firmware/qemu_fw_cfg top-level dir. */
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static u32 fw_cfg_rev;
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/* fw_cfg device i/o register addresses */
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static bool fw_cfg_is_mmio;
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static phys_addr_t fw_cfg_p_base;
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static resource_size_t fw_cfg_p_size;
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static void __iomem *fw_cfg_dev_base;
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static void __iomem *fw_cfg_reg_ctrl;
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static void __iomem *fw_cfg_reg_data;
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static void __iomem *fw_cfg_reg_dma;
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/* atomic access to fw_cfg device (potentially slow i/o, so using mutex) */
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static DEFINE_MUTEX(fw_cfg_dev_lock);
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/* pick appropriate endianness for selector key */
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static void fw_cfg_sel_endianness(u16 key)
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{
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if (fw_cfg_is_mmio)
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iowrite16be(key, fw_cfg_reg_ctrl);
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else
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iowrite16(key, fw_cfg_reg_ctrl);
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}
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#ifdef CONFIG_CRASH_CORE
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static inline bool fw_cfg_dma_enabled(void)
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{
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return (fw_cfg_rev & FW_CFG_VERSION_DMA) && fw_cfg_reg_dma;
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}
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/* qemu fw_cfg device is sync today, but spec says it may become async */
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static void fw_cfg_wait_for_control(struct fw_cfg_dma_access *d)
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{
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for (;;) {
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u32 ctrl = be32_to_cpu(READ_ONCE(d->control));
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/* do not reorder the read to d->control */
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rmb();
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if ((ctrl & ~FW_CFG_DMA_CTL_ERROR) == 0)
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return;
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cpu_relax();
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}
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}
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static ssize_t fw_cfg_dma_transfer(void *address, u32 length, u32 control)
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{
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phys_addr_t dma;
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struct fw_cfg_dma_access *d = NULL;
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ssize_t ret = length;
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d = kmalloc(sizeof(*d), GFP_KERNEL);
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if (!d) {
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ret = -ENOMEM;
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goto end;
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}
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/* fw_cfg device does not need IOMMU protection, so use physical addresses */
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*d = (struct fw_cfg_dma_access) {
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.address = cpu_to_be64(address ? virt_to_phys(address) : 0),
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.length = cpu_to_be32(length),
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.control = cpu_to_be32(control)
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};
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dma = virt_to_phys(d);
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iowrite32be((u64)dma >> 32, fw_cfg_reg_dma);
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/* force memory to sync before notifying device via MMIO */
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wmb();
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iowrite32be(dma, fw_cfg_reg_dma + 4);
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fw_cfg_wait_for_control(d);
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if (be32_to_cpu(READ_ONCE(d->control)) & FW_CFG_DMA_CTL_ERROR) {
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ret = -EIO;
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}
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end:
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kfree(d);
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return ret;
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}
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#endif
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/* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
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static ssize_t fw_cfg_read_blob(u16 key,
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void *buf, loff_t pos, size_t count)
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{
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u32 glk = -1U;
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acpi_status status;
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/* If we have ACPI, ensure mutual exclusion against any potential
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* device access by the firmware, e.g. via AML methods:
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*/
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status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
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if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
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/* Should never get here */
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WARN(1, "fw_cfg_read_blob: Failed to lock ACPI!\n");
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memset(buf, 0, count);
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return -EINVAL;
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}
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mutex_lock(&fw_cfg_dev_lock);
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fw_cfg_sel_endianness(key);
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while (pos-- > 0)
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ioread8(fw_cfg_reg_data);
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ioread8_rep(fw_cfg_reg_data, buf, count);
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mutex_unlock(&fw_cfg_dev_lock);
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acpi_release_global_lock(glk);
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return count;
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}
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#ifdef CONFIG_CRASH_CORE
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/* write chunk of given fw_cfg blob (caller responsible for sanity-check) */
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static ssize_t fw_cfg_write_blob(u16 key,
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void *buf, loff_t pos, size_t count)
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{
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u32 glk = -1U;
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acpi_status status;
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ssize_t ret = count;
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/* If we have ACPI, ensure mutual exclusion against any potential
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* device access by the firmware, e.g. via AML methods:
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*/
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status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
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if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
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/* Should never get here */
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WARN(1, "%s: Failed to lock ACPI!\n", __func__);
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return -EINVAL;
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}
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mutex_lock(&fw_cfg_dev_lock);
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if (pos == 0) {
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ret = fw_cfg_dma_transfer(buf, count, key << 16
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| FW_CFG_DMA_CTL_SELECT
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| FW_CFG_DMA_CTL_WRITE);
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} else {
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fw_cfg_sel_endianness(key);
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ret = fw_cfg_dma_transfer(NULL, pos, FW_CFG_DMA_CTL_SKIP);
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if (ret < 0)
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goto end;
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ret = fw_cfg_dma_transfer(buf, count, FW_CFG_DMA_CTL_WRITE);
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}
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end:
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mutex_unlock(&fw_cfg_dev_lock);
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acpi_release_global_lock(glk);
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return ret;
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}
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#endif /* CONFIG_CRASH_CORE */
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/* clean up fw_cfg device i/o */
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static void fw_cfg_io_cleanup(void)
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{
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if (fw_cfg_is_mmio) {
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iounmap(fw_cfg_dev_base);
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release_mem_region(fw_cfg_p_base, fw_cfg_p_size);
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} else {
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ioport_unmap(fw_cfg_dev_base);
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release_region(fw_cfg_p_base, fw_cfg_p_size);
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}
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}
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/* arch-specific ctrl & data register offsets are not available in ACPI, DT */
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#if !(defined(FW_CFG_CTRL_OFF) && defined(FW_CFG_DATA_OFF))
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# if (defined(CONFIG_ARM) || defined(CONFIG_ARM64))
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# define FW_CFG_CTRL_OFF 0x08
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# define FW_CFG_DATA_OFF 0x00
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# define FW_CFG_DMA_OFF 0x10
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# elif (defined(CONFIG_PPC_PMAC) || defined(CONFIG_SPARC32)) /* ppc/mac,sun4m */
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# define FW_CFG_CTRL_OFF 0x00
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# define FW_CFG_DATA_OFF 0x02
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# elif (defined(CONFIG_X86) || defined(CONFIG_SPARC64)) /* x86, sun4u */
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# define FW_CFG_CTRL_OFF 0x00
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# define FW_CFG_DATA_OFF 0x01
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# define FW_CFG_DMA_OFF 0x04
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# else
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# error "QEMU FW_CFG not available on this architecture!"
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# endif
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#endif
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/* initialize fw_cfg device i/o from platform data */
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static int fw_cfg_do_platform_probe(struct platform_device *pdev)
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{
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char sig[FW_CFG_SIG_SIZE];
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struct resource *range, *ctrl, *data, *dma;
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/* acquire i/o range details */
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fw_cfg_is_mmio = false;
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range = platform_get_resource(pdev, IORESOURCE_IO, 0);
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if (!range) {
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fw_cfg_is_mmio = true;
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range = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!range)
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return -EINVAL;
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}
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fw_cfg_p_base = range->start;
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fw_cfg_p_size = resource_size(range);
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if (fw_cfg_is_mmio) {
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if (!request_mem_region(fw_cfg_p_base,
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fw_cfg_p_size, "fw_cfg_mem"))
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return -EBUSY;
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fw_cfg_dev_base = ioremap(fw_cfg_p_base, fw_cfg_p_size);
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if (!fw_cfg_dev_base) {
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release_mem_region(fw_cfg_p_base, fw_cfg_p_size);
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return -EFAULT;
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}
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} else {
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if (!request_region(fw_cfg_p_base,
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fw_cfg_p_size, "fw_cfg_io"))
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return -EBUSY;
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fw_cfg_dev_base = ioport_map(fw_cfg_p_base, fw_cfg_p_size);
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if (!fw_cfg_dev_base) {
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release_region(fw_cfg_p_base, fw_cfg_p_size);
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return -EFAULT;
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}
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}
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/* were custom register offsets provided (e.g. on the command line)? */
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ctrl = platform_get_resource_byname(pdev, IORESOURCE_REG, "ctrl");
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data = platform_get_resource_byname(pdev, IORESOURCE_REG, "data");
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dma = platform_get_resource_byname(pdev, IORESOURCE_REG, "dma");
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if (ctrl && data) {
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fw_cfg_reg_ctrl = fw_cfg_dev_base + ctrl->start;
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fw_cfg_reg_data = fw_cfg_dev_base + data->start;
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} else {
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/* use architecture-specific offsets */
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fw_cfg_reg_ctrl = fw_cfg_dev_base + FW_CFG_CTRL_OFF;
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fw_cfg_reg_data = fw_cfg_dev_base + FW_CFG_DATA_OFF;
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}
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if (dma)
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fw_cfg_reg_dma = fw_cfg_dev_base + dma->start;
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#ifdef FW_CFG_DMA_OFF
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else
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fw_cfg_reg_dma = fw_cfg_dev_base + FW_CFG_DMA_OFF;
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#endif
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/* verify fw_cfg device signature */
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if (fw_cfg_read_blob(FW_CFG_SIGNATURE, sig,
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0, FW_CFG_SIG_SIZE) < 0 ||
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memcmp(sig, "QEMU", FW_CFG_SIG_SIZE) != 0) {
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fw_cfg_io_cleanup();
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return -ENODEV;
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}
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return 0;
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}
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static ssize_t fw_cfg_showrev(struct kobject *k, struct attribute *a, char *buf)
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{
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return sprintf(buf, "%u\n", fw_cfg_rev);
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}
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static const struct {
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struct attribute attr;
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ssize_t (*show)(struct kobject *k, struct attribute *a, char *buf);
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} fw_cfg_rev_attr = {
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.attr = { .name = "rev", .mode = S_IRUSR },
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.show = fw_cfg_showrev,
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};
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/* fw_cfg_sysfs_entry type */
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struct fw_cfg_sysfs_entry {
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struct kobject kobj;
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u32 size;
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u16 select;
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char name[FW_CFG_MAX_FILE_PATH];
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struct list_head list;
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};
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#ifdef CONFIG_CRASH_CORE
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static ssize_t fw_cfg_write_vmcoreinfo(const struct fw_cfg_file *f)
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{
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static struct fw_cfg_vmcoreinfo *data;
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ssize_t ret;
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data = kmalloc(sizeof(struct fw_cfg_vmcoreinfo), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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*data = (struct fw_cfg_vmcoreinfo) {
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.guest_format = cpu_to_le16(FW_CFG_VMCOREINFO_FORMAT_ELF),
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.size = cpu_to_le32(VMCOREINFO_NOTE_SIZE),
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.paddr = cpu_to_le64(paddr_vmcoreinfo_note())
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};
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/* spare ourself reading host format support for now since we
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* don't know what else to format - host may ignore ours
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*/
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ret = fw_cfg_write_blob(be16_to_cpu(f->select), data,
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0, sizeof(struct fw_cfg_vmcoreinfo));
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kfree(data);
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return ret;
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}
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#endif /* CONFIG_CRASH_CORE */
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/* get fw_cfg_sysfs_entry from kobject member */
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static inline struct fw_cfg_sysfs_entry *to_entry(struct kobject *kobj)
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{
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return container_of(kobj, struct fw_cfg_sysfs_entry, kobj);
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}
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/* fw_cfg_sysfs_attribute type */
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struct fw_cfg_sysfs_attribute {
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struct attribute attr;
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ssize_t (*show)(struct fw_cfg_sysfs_entry *entry, char *buf);
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};
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/* get fw_cfg_sysfs_attribute from attribute member */
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static inline struct fw_cfg_sysfs_attribute *to_attr(struct attribute *attr)
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{
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return container_of(attr, struct fw_cfg_sysfs_attribute, attr);
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}
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/* global cache of fw_cfg_sysfs_entry objects */
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static LIST_HEAD(fw_cfg_entry_cache);
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/* kobjects removed lazily by kernel, mutual exclusion needed */
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static DEFINE_SPINLOCK(fw_cfg_cache_lock);
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static inline void fw_cfg_sysfs_cache_enlist(struct fw_cfg_sysfs_entry *entry)
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{
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spin_lock(&fw_cfg_cache_lock);
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list_add_tail(&entry->list, &fw_cfg_entry_cache);
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spin_unlock(&fw_cfg_cache_lock);
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}
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static inline void fw_cfg_sysfs_cache_delist(struct fw_cfg_sysfs_entry *entry)
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{
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spin_lock(&fw_cfg_cache_lock);
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list_del(&entry->list);
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spin_unlock(&fw_cfg_cache_lock);
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}
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static void fw_cfg_sysfs_cache_cleanup(void)
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{
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struct fw_cfg_sysfs_entry *entry, *next;
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list_for_each_entry_safe(entry, next, &fw_cfg_entry_cache, list) {
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/* will end up invoking fw_cfg_sysfs_cache_delist()
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* via each object's release() method (i.e. destructor)
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*/
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kobject_put(&entry->kobj);
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}
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}
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/* default_attrs: per-entry attributes and show methods */
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#define FW_CFG_SYSFS_ATTR(_attr) \
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struct fw_cfg_sysfs_attribute fw_cfg_sysfs_attr_##_attr = { \
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.attr = { .name = __stringify(_attr), .mode = S_IRUSR }, \
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.show = fw_cfg_sysfs_show_##_attr, \
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}
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static ssize_t fw_cfg_sysfs_show_size(struct fw_cfg_sysfs_entry *e, char *buf)
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{
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return sprintf(buf, "%u\n", e->size);
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}
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static ssize_t fw_cfg_sysfs_show_key(struct fw_cfg_sysfs_entry *e, char *buf)
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{
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return sprintf(buf, "%u\n", e->select);
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}
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|
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static ssize_t fw_cfg_sysfs_show_name(struct fw_cfg_sysfs_entry *e, char *buf)
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{
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return sprintf(buf, "%s\n", e->name);
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}
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|
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static FW_CFG_SYSFS_ATTR(size);
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static FW_CFG_SYSFS_ATTR(key);
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static FW_CFG_SYSFS_ATTR(name);
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|
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static struct attribute *fw_cfg_sysfs_entry_attrs[] = {
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&fw_cfg_sysfs_attr_size.attr,
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&fw_cfg_sysfs_attr_key.attr,
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&fw_cfg_sysfs_attr_name.attr,
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NULL,
|
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};
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|
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/* sysfs_ops: find fw_cfg_[entry, attribute] and call appropriate show method */
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static ssize_t fw_cfg_sysfs_attr_show(struct kobject *kobj, struct attribute *a,
|
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char *buf)
|
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{
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struct fw_cfg_sysfs_entry *entry = to_entry(kobj);
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struct fw_cfg_sysfs_attribute *attr = to_attr(a);
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|
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return attr->show(entry, buf);
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}
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|
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static const struct sysfs_ops fw_cfg_sysfs_attr_ops = {
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.show = fw_cfg_sysfs_attr_show,
|
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};
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|
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/* release: destructor, to be called via kobject_put() */
|
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static void fw_cfg_sysfs_release_entry(struct kobject *kobj)
|
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{
|
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struct fw_cfg_sysfs_entry *entry = to_entry(kobj);
|
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|
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fw_cfg_sysfs_cache_delist(entry);
|
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kfree(entry);
|
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}
|
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|
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/* kobj_type: ties together all properties required to register an entry */
|
|
static struct kobj_type fw_cfg_sysfs_entry_ktype = {
|
|
.default_attrs = fw_cfg_sysfs_entry_attrs,
|
|
.sysfs_ops = &fw_cfg_sysfs_attr_ops,
|
|
.release = fw_cfg_sysfs_release_entry,
|
|
};
|
|
|
|
/* raw-read method and attribute */
|
|
static ssize_t fw_cfg_sysfs_read_raw(struct file *filp, struct kobject *kobj,
|
|
struct bin_attribute *bin_attr,
|
|
char *buf, loff_t pos, size_t count)
|
|
{
|
|
struct fw_cfg_sysfs_entry *entry = to_entry(kobj);
|
|
|
|
if (pos > entry->size)
|
|
return -EINVAL;
|
|
|
|
if (count > entry->size - pos)
|
|
count = entry->size - pos;
|
|
|
|
return fw_cfg_read_blob(entry->select, buf, pos, count);
|
|
}
|
|
|
|
static struct bin_attribute fw_cfg_sysfs_attr_raw = {
|
|
.attr = { .name = "raw", .mode = S_IRUSR },
|
|
.read = fw_cfg_sysfs_read_raw,
|
|
};
|
|
|
|
/*
|
|
* Create a kset subdirectory matching each '/' delimited dirname token
|
|
* in 'name', starting with sysfs kset/folder 'dir'; At the end, create
|
|
* a symlink directed at the given 'target'.
|
|
* NOTE: We do this on a best-effort basis, since 'name' is not guaranteed
|
|
* to be a well-behaved path name. Whenever a symlink vs. kset directory
|
|
* name collision occurs, the kernel will issue big scary warnings while
|
|
* refusing to add the offending link or directory. We follow up with our
|
|
* own, slightly less scary error messages explaining the situation :)
|
|
*/
|
|
static int fw_cfg_build_symlink(struct kset *dir,
|
|
struct kobject *target, const char *name)
|
|
{
|
|
int ret;
|
|
struct kset *subdir;
|
|
struct kobject *ko;
|
|
char *name_copy, *p, *tok;
|
|
|
|
if (!dir || !target || !name || !*name)
|
|
return -EINVAL;
|
|
|
|
/* clone a copy of name for parsing */
|
|
name_copy = p = kstrdup(name, GFP_KERNEL);
|
|
if (!name_copy)
|
|
return -ENOMEM;
|
|
|
|
/* create folders for each dirname token, then symlink for basename */
|
|
while ((tok = strsep(&p, "/")) && *tok) {
|
|
|
|
/* last (basename) token? If so, add symlink here */
|
|
if (!p || !*p) {
|
|
ret = sysfs_create_link(&dir->kobj, target, tok);
|
|
break;
|
|
}
|
|
|
|
/* does the current dir contain an item named after tok ? */
|
|
ko = kset_find_obj(dir, tok);
|
|
if (ko) {
|
|
/* drop reference added by kset_find_obj */
|
|
kobject_put(ko);
|
|
|
|
/* ko MUST be a kset - we're about to use it as one ! */
|
|
if (ko->ktype != dir->kobj.ktype) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
/* descend into already existing subdirectory */
|
|
dir = to_kset(ko);
|
|
} else {
|
|
/* create new subdirectory kset */
|
|
subdir = kzalloc(sizeof(struct kset), GFP_KERNEL);
|
|
if (!subdir) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
subdir->kobj.kset = dir;
|
|
subdir->kobj.ktype = dir->kobj.ktype;
|
|
ret = kobject_set_name(&subdir->kobj, "%s", tok);
|
|
if (ret) {
|
|
kfree(subdir);
|
|
break;
|
|
}
|
|
ret = kset_register(subdir);
|
|
if (ret) {
|
|
kfree(subdir);
|
|
break;
|
|
}
|
|
|
|
/* descend into newly created subdirectory */
|
|
dir = subdir;
|
|
}
|
|
}
|
|
|
|
/* we're done with cloned copy of name */
|
|
kfree(name_copy);
|
|
return ret;
|
|
}
|
|
|
|
/* recursively unregister fw_cfg/by_name/ kset directory tree */
|
|
static void fw_cfg_kset_unregister_recursive(struct kset *kset)
|
|
{
|
|
struct kobject *k, *next;
|
|
|
|
list_for_each_entry_safe(k, next, &kset->list, entry)
|
|
/* all set members are ksets too, but check just in case... */
|
|
if (k->ktype == kset->kobj.ktype)
|
|
fw_cfg_kset_unregister_recursive(to_kset(k));
|
|
|
|
/* symlinks are cleanly and automatically removed with the directory */
|
|
kset_unregister(kset);
|
|
}
|
|
|
|
/* kobjects & kset representing top-level, by_key, and by_name folders */
|
|
static struct kobject *fw_cfg_top_ko;
|
|
static struct kobject *fw_cfg_sel_ko;
|
|
static struct kset *fw_cfg_fname_kset;
|
|
|
|
/* register an individual fw_cfg file */
|
|
static int fw_cfg_register_file(const struct fw_cfg_file *f)
|
|
{
|
|
int err;
|
|
struct fw_cfg_sysfs_entry *entry;
|
|
|
|
#ifdef CONFIG_CRASH_CORE
|
|
if (fw_cfg_dma_enabled() &&
|
|
strcmp(f->name, FW_CFG_VMCOREINFO_FILENAME) == 0 &&
|
|
!is_kdump_kernel()) {
|
|
if (fw_cfg_write_vmcoreinfo(f) < 0)
|
|
pr_warn("fw_cfg: failed to write vmcoreinfo");
|
|
}
|
|
#endif
|
|
|
|
/* allocate new entry */
|
|
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (!entry)
|
|
return -ENOMEM;
|
|
|
|
/* set file entry information */
|
|
entry->size = be32_to_cpu(f->size);
|
|
entry->select = be16_to_cpu(f->select);
|
|
memcpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH);
|
|
|
|
/* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */
|
|
err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype,
|
|
fw_cfg_sel_ko, "%d", entry->select);
|
|
if (err) {
|
|
kobject_put(&entry->kobj);
|
|
return err;
|
|
}
|
|
|
|
/* add raw binary content access */
|
|
err = sysfs_create_bin_file(&entry->kobj, &fw_cfg_sysfs_attr_raw);
|
|
if (err)
|
|
goto err_add_raw;
|
|
|
|
/* try adding "/sys/firmware/qemu_fw_cfg/by_name/" symlink */
|
|
fw_cfg_build_symlink(fw_cfg_fname_kset, &entry->kobj, entry->name);
|
|
|
|
/* success, add entry to global cache */
|
|
fw_cfg_sysfs_cache_enlist(entry);
|
|
return 0;
|
|
|
|
err_add_raw:
|
|
kobject_del(&entry->kobj);
|
|
kfree(entry);
|
|
return err;
|
|
}
|
|
|
|
/* iterate over all fw_cfg directory entries, registering each one */
|
|
static int fw_cfg_register_dir_entries(void)
|
|
{
|
|
int ret = 0;
|
|
__be32 files_count;
|
|
u32 count, i;
|
|
struct fw_cfg_file *dir;
|
|
size_t dir_size;
|
|
|
|
ret = fw_cfg_read_blob(FW_CFG_FILE_DIR, &files_count,
|
|
0, sizeof(files_count));
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
count = be32_to_cpu(files_count);
|
|
dir_size = count * sizeof(struct fw_cfg_file);
|
|
|
|
dir = kmalloc(dir_size, GFP_KERNEL);
|
|
if (!dir)
|
|
return -ENOMEM;
|
|
|
|
ret = fw_cfg_read_blob(FW_CFG_FILE_DIR, dir,
|
|
sizeof(files_count), dir_size);
|
|
if (ret < 0)
|
|
goto end;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
ret = fw_cfg_register_file(&dir[i]);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
end:
|
|
kfree(dir);
|
|
return ret;
|
|
}
|
|
|
|
/* unregister top-level or by_key folder */
|
|
static inline void fw_cfg_kobj_cleanup(struct kobject *kobj)
|
|
{
|
|
kobject_del(kobj);
|
|
kobject_put(kobj);
|
|
}
|
|
|
|
static int fw_cfg_sysfs_probe(struct platform_device *pdev)
|
|
{
|
|
int err;
|
|
__le32 rev;
|
|
|
|
/* NOTE: If we supported multiple fw_cfg devices, we'd first create
|
|
* a subdirectory named after e.g. pdev->id, then hang per-device
|
|
* by_key (and by_name) subdirectories underneath it. However, only
|
|
* one fw_cfg device exist system-wide, so if one was already found
|
|
* earlier, we might as well stop here.
|
|
*/
|
|
if (fw_cfg_sel_ko)
|
|
return -EBUSY;
|
|
|
|
/* create by_key and by_name subdirs of /sys/firmware/qemu_fw_cfg/ */
|
|
err = -ENOMEM;
|
|
fw_cfg_sel_ko = kobject_create_and_add("by_key", fw_cfg_top_ko);
|
|
if (!fw_cfg_sel_ko)
|
|
goto err_sel;
|
|
fw_cfg_fname_kset = kset_create_and_add("by_name", NULL, fw_cfg_top_ko);
|
|
if (!fw_cfg_fname_kset)
|
|
goto err_name;
|
|
|
|
/* initialize fw_cfg device i/o from platform data */
|
|
err = fw_cfg_do_platform_probe(pdev);
|
|
if (err)
|
|
goto err_probe;
|
|
|
|
/* get revision number, add matching top-level attribute */
|
|
err = fw_cfg_read_blob(FW_CFG_ID, &rev, 0, sizeof(rev));
|
|
if (err < 0)
|
|
goto err_probe;
|
|
|
|
fw_cfg_rev = le32_to_cpu(rev);
|
|
err = sysfs_create_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr);
|
|
if (err)
|
|
goto err_rev;
|
|
|
|
/* process fw_cfg file directory entry, registering each file */
|
|
err = fw_cfg_register_dir_entries();
|
|
if (err)
|
|
goto err_dir;
|
|
|
|
/* success */
|
|
pr_debug("fw_cfg: loaded.\n");
|
|
return 0;
|
|
|
|
err_dir:
|
|
fw_cfg_sysfs_cache_cleanup();
|
|
sysfs_remove_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr);
|
|
err_rev:
|
|
fw_cfg_io_cleanup();
|
|
err_probe:
|
|
fw_cfg_kset_unregister_recursive(fw_cfg_fname_kset);
|
|
err_name:
|
|
fw_cfg_kobj_cleanup(fw_cfg_sel_ko);
|
|
err_sel:
|
|
return err;
|
|
}
|
|
|
|
static int fw_cfg_sysfs_remove(struct platform_device *pdev)
|
|
{
|
|
pr_debug("fw_cfg: unloading.\n");
|
|
fw_cfg_sysfs_cache_cleanup();
|
|
sysfs_remove_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr);
|
|
fw_cfg_io_cleanup();
|
|
fw_cfg_kset_unregister_recursive(fw_cfg_fname_kset);
|
|
fw_cfg_kobj_cleanup(fw_cfg_sel_ko);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id fw_cfg_sysfs_mmio_match[] = {
|
|
{ .compatible = "qemu,fw-cfg-mmio", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, fw_cfg_sysfs_mmio_match);
|
|
|
|
#ifdef CONFIG_ACPI
|
|
static const struct acpi_device_id fw_cfg_sysfs_acpi_match[] = {
|
|
{ FW_CFG_ACPI_DEVICE_ID, },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, fw_cfg_sysfs_acpi_match);
|
|
#endif
|
|
|
|
static struct platform_driver fw_cfg_sysfs_driver = {
|
|
.probe = fw_cfg_sysfs_probe,
|
|
.remove = fw_cfg_sysfs_remove,
|
|
.driver = {
|
|
.name = "fw_cfg",
|
|
.of_match_table = fw_cfg_sysfs_mmio_match,
|
|
.acpi_match_table = ACPI_PTR(fw_cfg_sysfs_acpi_match),
|
|
},
|
|
};
|
|
|
|
#ifdef CONFIG_FW_CFG_SYSFS_CMDLINE
|
|
|
|
static struct platform_device *fw_cfg_cmdline_dev;
|
|
|
|
/* this probably belongs in e.g. include/linux/types.h,
|
|
* but right now we are the only ones doing it...
|
|
*/
|
|
#ifdef CONFIG_PHYS_ADDR_T_64BIT
|
|
#define __PHYS_ADDR_PREFIX "ll"
|
|
#else
|
|
#define __PHYS_ADDR_PREFIX ""
|
|
#endif
|
|
|
|
/* use special scanf/printf modifier for phys_addr_t, resource_size_t */
|
|
#define PH_ADDR_SCAN_FMT "@%" __PHYS_ADDR_PREFIX "i%n" \
|
|
":%" __PHYS_ADDR_PREFIX "i" \
|
|
":%" __PHYS_ADDR_PREFIX "i%n" \
|
|
":%" __PHYS_ADDR_PREFIX "i%n"
|
|
|
|
#define PH_ADDR_PR_1_FMT "0x%" __PHYS_ADDR_PREFIX "x@" \
|
|
"0x%" __PHYS_ADDR_PREFIX "x"
|
|
|
|
#define PH_ADDR_PR_3_FMT PH_ADDR_PR_1_FMT \
|
|
":%" __PHYS_ADDR_PREFIX "u" \
|
|
":%" __PHYS_ADDR_PREFIX "u"
|
|
|
|
#define PH_ADDR_PR_4_FMT PH_ADDR_PR_3_FMT \
|
|
":%" __PHYS_ADDR_PREFIX "u"
|
|
|
|
static int fw_cfg_cmdline_set(const char *arg, const struct kernel_param *kp)
|
|
{
|
|
struct resource res[4] = {};
|
|
char *str;
|
|
phys_addr_t base;
|
|
resource_size_t size, ctrl_off, data_off, dma_off;
|
|
int processed, consumed = 0;
|
|
|
|
/* only one fw_cfg device can exist system-wide, so if one
|
|
* was processed on the command line already, we might as
|
|
* well stop here.
|
|
*/
|
|
if (fw_cfg_cmdline_dev) {
|
|
/* avoid leaking previously registered device */
|
|
platform_device_unregister(fw_cfg_cmdline_dev);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* consume "<size>" portion of command line argument */
|
|
size = memparse(arg, &str);
|
|
|
|
/* get "@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]" chunks */
|
|
processed = sscanf(str, PH_ADDR_SCAN_FMT,
|
|
&base, &consumed,
|
|
&ctrl_off, &data_off, &consumed,
|
|
&dma_off, &consumed);
|
|
|
|
/* sscanf() must process precisely 1, 3 or 4 chunks:
|
|
* <base> is mandatory, optionally followed by <ctrl_off>
|
|
* and <data_off>, and <dma_off>;
|
|
* there must be no extra characters after the last chunk,
|
|
* so str[consumed] must be '\0'.
|
|
*/
|
|
if (str[consumed] ||
|
|
(processed != 1 && processed != 3 && processed != 4))
|
|
return -EINVAL;
|
|
|
|
res[0].start = base;
|
|
res[0].end = base + size - 1;
|
|
res[0].flags = !strcmp(kp->name, "mmio") ? IORESOURCE_MEM :
|
|
IORESOURCE_IO;
|
|
|
|
/* insert register offsets, if provided */
|
|
if (processed > 1) {
|
|
res[1].name = "ctrl";
|
|
res[1].start = ctrl_off;
|
|
res[1].flags = IORESOURCE_REG;
|
|
res[2].name = "data";
|
|
res[2].start = data_off;
|
|
res[2].flags = IORESOURCE_REG;
|
|
}
|
|
if (processed > 3) {
|
|
res[3].name = "dma";
|
|
res[3].start = dma_off;
|
|
res[3].flags = IORESOURCE_REG;
|
|
}
|
|
|
|
/* "processed" happens to nicely match the number of resources
|
|
* we need to pass in to this platform device.
|
|
*/
|
|
fw_cfg_cmdline_dev = platform_device_register_simple("fw_cfg",
|
|
PLATFORM_DEVID_NONE, res, processed);
|
|
|
|
return PTR_ERR_OR_ZERO(fw_cfg_cmdline_dev);
|
|
}
|
|
|
|
static int fw_cfg_cmdline_get(char *buf, const struct kernel_param *kp)
|
|
{
|
|
/* stay silent if device was not configured via the command
|
|
* line, or if the parameter name (ioport/mmio) doesn't match
|
|
* the device setting
|
|
*/
|
|
if (!fw_cfg_cmdline_dev ||
|
|
(!strcmp(kp->name, "mmio") ^
|
|
(fw_cfg_cmdline_dev->resource[0].flags == IORESOURCE_MEM)))
|
|
return 0;
|
|
|
|
switch (fw_cfg_cmdline_dev->num_resources) {
|
|
case 1:
|
|
return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_1_FMT,
|
|
resource_size(&fw_cfg_cmdline_dev->resource[0]),
|
|
fw_cfg_cmdline_dev->resource[0].start);
|
|
case 3:
|
|
return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_3_FMT,
|
|
resource_size(&fw_cfg_cmdline_dev->resource[0]),
|
|
fw_cfg_cmdline_dev->resource[0].start,
|
|
fw_cfg_cmdline_dev->resource[1].start,
|
|
fw_cfg_cmdline_dev->resource[2].start);
|
|
case 4:
|
|
return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_4_FMT,
|
|
resource_size(&fw_cfg_cmdline_dev->resource[0]),
|
|
fw_cfg_cmdline_dev->resource[0].start,
|
|
fw_cfg_cmdline_dev->resource[1].start,
|
|
fw_cfg_cmdline_dev->resource[2].start,
|
|
fw_cfg_cmdline_dev->resource[3].start);
|
|
}
|
|
|
|
/* Should never get here */
|
|
WARN(1, "Unexpected number of resources: %d\n",
|
|
fw_cfg_cmdline_dev->num_resources);
|
|
return 0;
|
|
}
|
|
|
|
static const struct kernel_param_ops fw_cfg_cmdline_param_ops = {
|
|
.set = fw_cfg_cmdline_set,
|
|
.get = fw_cfg_cmdline_get,
|
|
};
|
|
|
|
device_param_cb(ioport, &fw_cfg_cmdline_param_ops, NULL, S_IRUSR);
|
|
device_param_cb(mmio, &fw_cfg_cmdline_param_ops, NULL, S_IRUSR);
|
|
|
|
#endif /* CONFIG_FW_CFG_SYSFS_CMDLINE */
|
|
|
|
static int __init fw_cfg_sysfs_init(void)
|
|
{
|
|
int ret;
|
|
|
|
/* create /sys/firmware/qemu_fw_cfg/ top level directory */
|
|
fw_cfg_top_ko = kobject_create_and_add("qemu_fw_cfg", firmware_kobj);
|
|
if (!fw_cfg_top_ko)
|
|
return -ENOMEM;
|
|
|
|
ret = platform_driver_register(&fw_cfg_sysfs_driver);
|
|
if (ret)
|
|
fw_cfg_kobj_cleanup(fw_cfg_top_ko);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit fw_cfg_sysfs_exit(void)
|
|
{
|
|
platform_driver_unregister(&fw_cfg_sysfs_driver);
|
|
|
|
#ifdef CONFIG_FW_CFG_SYSFS_CMDLINE
|
|
platform_device_unregister(fw_cfg_cmdline_dev);
|
|
#endif
|
|
|
|
/* clean up /sys/firmware/qemu_fw_cfg/ */
|
|
fw_cfg_kobj_cleanup(fw_cfg_top_ko);
|
|
}
|
|
|
|
module_init(fw_cfg_sysfs_init);
|
|
module_exit(fw_cfg_sysfs_exit);
|