[PATCH v6] pci: read amd iommu virtual address width

[Michael Piszczek <mpiszczek@ddn.com>]

Add code to read the virtual address width for AMD processors.
Updated pci_device_iommu_support_va() to use glob to find iommu
capability files.

Signed-off-by: Michael Piszczek <mpiszczek@ddn.com>
---
 drivers/bus/pci/linux/pci.c | 58 ++++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 23 deletions(-)

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index ebd1395502..291090ba7b 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -4,6 +4,7 @@
 
 #include <string.h>
 #include <dirent.h>
+#include <glob.h>
 
 #include <rte_log.h>
 #include <rte_pci.h>
@@ -480,42 +481,53 @@ rte_pci_scan(void)
 }
 
 #if defined(RTE_ARCH_X86)
+
 bool
 pci_device_iommu_support_va(const struct rte_pci_device *dev)
 {
-#define VTD_CAP_MGAW_SHIFT	16
-#define VTD_CAP_MGAW_MASK	(0x3fULL << VTD_CAP_MGAW_SHIFT)
+#define VTD_CAP_MGAW_SHIFT      16
+#define VTD_CAP_MGAW_MASK       (0x3fULL << VTD_CAP_MGAW_SHIFT)
+#define RD_AMD_CAP_VASIZE_SHIFT 15
+#define RD_AMD_CAP_VASIZE_MASK  (0x7F << RD_AMD_CAP_VASIZE_SHIFT)
+	int rc;
 	const struct rte_pci_addr *addr = &dev->addr;
-	char filename[PATH_MAX];
-	FILE *fp;
-	uint64_t mgaw, vtd_cap_reg = 0;
+	char pattern[PATH_MAX];
+	glob_t glob_results;
+	uint64_t mgaw = 0;
 
-	snprintf(filename, sizeof(filename),
-		 "%s/" PCI_PRI_FMT "/iommu/intel-iommu/cap",
+	snprintf(pattern, sizeof(pattern),
+		 "%s/" PCI_PRI_FMT "/iommu/*-iommu/cap",
 		 rte_pci_get_sysfs_path(), addr->domain, addr->bus, addr->devid,
 		 addr->function);
 
-	fp = fopen(filename, "r");
-	if (fp == NULL) {
-		/* We don't have an Intel IOMMU, assume VA supported */
-		if (errno == ENOENT)
-			return true;
+	rc = glob(pattern, 0, NULL, &glob_results);
+	if (rc != 0 && glob_results.gl_pathc == 1) {
+		const char *filename = glob_results.gl_pathv[0];
+		FILE *fp = fopen(filename, "r");
 
-		RTE_LOG(ERR, EAL, "%s(): can't open %s: %s\n",
-			__func__, filename, strerror(errno));
-		return false;
-	}
+		if (fp != NULL) {
+			uint64_t cap_reg = 0;
 
-	/* We have an Intel IOMMU */
-	if (fscanf(fp, "%" PRIx64, &vtd_cap_reg) != 1) {
-		RTE_LOG(ERR, EAL, "%s(): can't read %s\n", __func__, filename);
-		fclose(fp);
-		return false;
+			if (fscanf(fp, "%" PRIx64, &cap_reg) != 1) {
+				RTE_LOG(ERR, EAL, "%s(): can't read %s\n", __func__, filename);
+			}
+			else if (strstr(filename, "intel-iommu") != NULL) {
+				/* We have an Intel IOMMU */
+				mgaw = ((cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
+			}
+			else if (strstr(filename, "amd-iommu") != NULL) {
+				/* We have an Amd IOMMU */
+				mgaw = ((cap_reg & RD_AMD_CAP_VASIZE_MASK) >> RD_AMD_CAP_VASIZE_SHIFT) + 1;
+			}
+
+			fclose(fp);
+		}
 	}
 
-	fclose(fp);
+	globfree(&glob_results);
 
-	mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
+	if (mgaw == 0)
+		return false;
 
 	/*
 	 * Assuming there is no limitation by now. We can not know at this point
-- 
2.34.1