Add a debugfs entry to dump the active device table entries from the IOMMU's table. Active is determined by non-default values in the first and second long words of the DTE. Aside from IOMMU devices, this output should list every device reported by lspci.
Signed-off-by: Gary R Hook <[email protected]> --- drivers/iommu/amd_iommu_debugfs.c | 60 +++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/drivers/iommu/amd_iommu_debugfs.c b/drivers/iommu/amd_iommu_debugfs.c index d95428b1ef90..1d941c5329be 100644 --- a/drivers/iommu/amd_iommu_debugfs.c +++ b/drivers/iommu/amd_iommu_debugfs.c @@ -92,9 +92,62 @@ static const struct file_operations amd_iommu_debugfs_dtecount_ops = { .write = NULL, }; +#define MAX_PCI_ID 0xFFFF + +#define PRINTDTE(i) OSCNPRINTF("%02x:%02x:%x - %016llx %016llx %016llx %016llx\n", \ + PCI_BUS_NUM(i), PCI_SLOT(i), PCI_FUNC(i), \ + amd_iommu_dev_table[i].data[0], \ + amd_iommu_dev_table[i].data[1], \ + amd_iommu_dev_table[i].data[2], \ + amd_iommu_dev_table[i].data[3]); + +static ssize_t amd_iommu_debugfs_dte_read(struct file *filp, + char __user *ubuf, + size_t count, loff_t *offp) +{ + unsigned int obuflen; + unsigned int oboff = 0; + unsigned int istart, iend; + ssize_t ret; + u32 i, n; + char *obuf; + + /* Count the number of valid entries in the device table */ + istart = 0; + iend = MAX_PCI_ID; + n = amd_iommu_count_valid_dtes(istart, iend); + obuflen = n * 80; + + obuf = kmalloc(OBUFLEN, GFP_KERNEL); + if (!obuf) + return -ENOMEM; + + for (i = istart ; i <= iend ; i++) + if ((amd_iommu_dev_table[i].data[0] ^ 0x3) + || amd_iommu_dev_table[i].data[1]) + oboff += PRINTDTE(i); + + ret = simple_read_from_buffer(ubuf, count, offp, obuf, oboff); + kfree(obuf); + + return ret; +} + +static const struct file_operations amd_iommu_debugfs_dte_ops = { + .owner = THIS_MODULE, + .open = simple_open, + .read = amd_iommu_debugfs_dte_read, + .write = NULL, +}; + static char readmetext[] = +"devicetable Print active entries in the device table\n" "count Count of active devices\n" "verbose Provide additional descriptive text\n" +"\n" +" Dumping the Device Table\n" +"The device table is scanned for entries that appear to be active. The\n" +"default range is from 0 to 0xFFFF, and only active entries will be reported\n" "\n"; static ssize_t amd_iommu_debugfs_readme_read(struct file *filp, @@ -144,6 +197,13 @@ void amd_iommu_debugfs_setup(struct amd_iommu *iommu) if (!d_verbose) goto err; + /* Device Table Entries */ + d_dte = debugfs_create_file("devicetable", 0400, + iommu->debugfs_instance, iommu, + &amd_iommu_debugfs_dte_ops); + if (!d_dte) + goto err; + d_dte = debugfs_create_file("count", 0400, iommu->debugfs_instance, iommu, &amd_iommu_debugfs_dtecount_ops);
