forked from Minki/linux
2d6d60a3d3
If the "etc/vmcoreinfo" fw_cfg file is present and we are not running the kdump kernel, write the addr/size of the vmcoreinfo ELF note. The DMA operation is expected to run synchronously with today qemu, but the specification states that it may become async, so we run "control" field check in a loop for eventual changes. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
940 lines
25 KiB
C
940 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/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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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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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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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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/* 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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return attr->show(entry, buf);
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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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/* 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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fw_cfg_sysfs_cache_delist(entry);
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kfree(entry);
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}
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/* kobj_type: ties together all properties required to register an entry */
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static struct kobj_type fw_cfg_sysfs_entry_ktype = {
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.default_attrs = fw_cfg_sysfs_entry_attrs,
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.sysfs_ops = &fw_cfg_sysfs_attr_ops,
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.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)
|
|
goto err_register;
|
|
|
|
/* 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);
|
|
err_register:
|
|
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);
|