[linux] Use generic sysfs mechanism to read SMBIOS table

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/include/ipxe/smbios.h b/src/include/ipxe/smbios.h
index 53fbd8cb89f323b3dd17ac93d6fb34c6054beec2..42278fb245c54df4e07a4c492336c3d5280a3639 100644 (file)
--- a/src/include/ipxe/smbios.h
+++ b/src/include/ipxe/smbios.h
@@ -235,5 +235,6 @@ extern int read_smbios_string ( struct smbios_structure *structure,
                                unsigned int index,
                                void *data, size_t len );
 extern int smbios_version ( void );
+extern void smbios_clear ( void );
 
 #endif /* _IPXE_SMBIOS_H */

diff --git a/src/interface/linux/linux_smbios.c b/src/interface/linux/linux_smbios.c
index 494a60bd948c65b314ca0f146793e181b6d4f20b..981873943b93dd74582dc3c0c449ec1793f5935b 100644 (file)
--- a/src/interface/linux/linux_smbios.c
+++ b/src/interface/linux/linux_smbios.c
@@ -21,20 +21,21 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 #include <errno.h>
 #include <ipxe/linux_api.h>
+#include <ipxe/linux_sysfs.h>
 #include <ipxe/linux.h>
+#include <ipxe/umalloc.h>
+#include <ipxe/init.h>
 #include <ipxe/smbios.h>
 
-/** SMBIOS filename */
-static const char smbios_filename[] = "/dev/mem";
-
-/** SMBIOS entry point scan region start address */
-#define SMBIOS_ENTRY_START 0xf0000
+/** SMBIOS entry point filename */
+static const char smbios_entry_filename[] =
+       "/sys/firmware/dmi/tables/smbios_entry_point";
 
-/** SMBIOS entry point scan region length */
-#define SMBIOS_ENTRY_LEN 0x10000
+/** SMBIOS filename */
+static const char smbios_filename[] = "/sys/firmware/dmi/tables/DMI";
 
-/** SMBIOS mapping alignment */
-#define SMBIOS_ALIGN 0x1000
+/** Cache SMBIOS data */
+static userptr_t smbios_data;
 
 /**
  * Find SMBIOS
@@ -43,73 +44,84 @@ static const char smbios_filename[] = "/dev/mem";
  * @ret rc             Return status code
  */
 static int linux_find_smbios ( struct smbios *smbios ) {
-       struct smbios_entry entry;
-       void *entry_mem;
-       void *smbios_mem;
-       size_t smbios_offset;
-       size_t smbios_indent;
-       size_t smbios_len;
-       int fd;
+       struct smbios3_entry *smbios3_entry;
+       struct smbios_entry *smbios_entry;
+       userptr_t entry;
+       void *data;
+       int len;
        int rc;
 
-       /* Open SMBIOS file */
-       fd = linux_open ( smbios_filename, O_RDONLY );
-       if ( fd < 0 ) {
-               rc = -ELINUX ( linux_errno );
-               DBGC ( smbios, "SMBIOS could not open %s: %s\n",
-                      smbios_filename, linux_strerror ( linux_errno ) );
-               goto err_open;
+       /* Read entry point file */
+       len = linux_sysfs_read ( smbios_entry_filename, &entry );
+       if ( len < 0 ) {
+               rc = len;
+               DBGC ( smbios, "SMBIOS could not read %s: %s\n",
+                      smbios_entry_filename, strerror ( rc ) );
+               goto err_entry;
        }
-
-       /* Map the region potentially containing the SMBIOS entry point */
-       entry_mem = linux_mmap ( NULL, SMBIOS_ENTRY_LEN, PROT_READ, MAP_SHARED,
-                                fd, SMBIOS_ENTRY_START );
-       if ( entry_mem == MAP_FAILED ) {
-               rc = -ELINUX ( linux_errno );
-               DBGC ( smbios, "SMBIOS could not mmap %s (%#x+%#x): %s\n",
-                      smbios_filename, SMBIOS_ENTRY_START, SMBIOS_ENTRY_LEN,
-                      linux_strerror ( linux_errno ) );
-               goto err_mmap_entry;
+       data = user_to_virt ( entry, 0 );
+       smbios3_entry = data;
+       smbios_entry = data;
+       if ( ( len >= ( ( int ) sizeof ( *smbios3_entry ) ) ) &&
+            ( smbios3_entry->signature == SMBIOS3_SIGNATURE ) ) {
+               smbios->version = SMBIOS_VERSION ( smbios3_entry->major,
+                                                  smbios3_entry->minor );
+       } else if ( ( len >= ( ( int ) sizeof ( *smbios_entry ) ) ) &&
+                   ( smbios_entry->signature == SMBIOS_SIGNATURE ) ) {
+               smbios->version = SMBIOS_VERSION ( smbios_entry->major,
+                                                  smbios_entry->minor );
+       } else {
+               DBGC ( smbios, "SMBIOS invalid entry point %s:\n",
+                      smbios_entry_filename );
+               DBGC_HDA ( smbios, 0, data, len );
+               rc = -EINVAL;
+               goto err_version;
        }
 
-       /* Scan for the SMBIOS entry point */
-       if ( ( rc = find_smbios_entry ( virt_to_user ( entry_mem ),
-                                       SMBIOS_ENTRY_LEN, &entry ) ) != 0 )
-               goto err_find_entry;
-
-       /* Map the region containing the SMBIOS structures */
-       smbios_indent = ( entry.smbios_address & ( SMBIOS_ALIGN - 1 ) );
-       smbios_offset = ( entry.smbios_address - smbios_indent );
-       smbios_len = ( entry.smbios_len + smbios_indent );
-       smbios_mem = linux_mmap ( NULL, smbios_len, PROT_READ, MAP_SHARED,
-                                 fd, smbios_offset );
-       if ( smbios_mem == MAP_FAILED ) {
-               rc = -ELINUX ( linux_errno );
-               DBGC ( smbios, "SMBIOS could not mmap %s (%#zx+%#zx): %s\n",
-                      smbios_filename, smbios_offset, smbios_len,
-                      linux_strerror ( linux_errno ) );
-               goto err_mmap_smbios;
+       /* Read SMBIOS file */
+       len = linux_sysfs_read ( smbios_filename, &smbios_data );
+       if ( len < 0 ) {
+               rc = len;
+               DBGC ( smbios, "SMBIOS could not read %s: %s\n",
+                      smbios_filename, strerror ( rc ) );
+               goto err_read;
        }
 
-       /* Fill in entry point descriptor structure */
-       smbios->address = virt_to_user ( smbios_mem + smbios_indent );
-       smbios->len = entry.smbios_len;
-       smbios->count = entry.smbios_count;
-       smbios->version = SMBIOS_VERSION ( entry.major, entry.minor );
+       /* Populate SMBIOS descriptor */
+       smbios->address = smbios_data;
+       smbios->len = len;
+       smbios->count = 0;
 
-       /* Unmap the entry point region (no longer required) */
-       linux_munmap ( entry_mem, SMBIOS_ENTRY_LEN );
+       /* Free entry point */
+       ufree ( entry );
 
        return 0;
 
-       linux_munmap ( smbios_mem, smbios_len );
- err_mmap_smbios:
- err_find_entry:
-       linux_munmap ( entry_mem, SMBIOS_ENTRY_LEN );
- err_mmap_entry:
-       linux_close ( fd );
- err_open:
+       ufree ( smbios_data );
+ err_read:
+ err_version:
+       ufree ( entry );
+ err_entry:
        return rc;
 }
 
+/**
+ * Free cached SMBIOS data
+ *
+ */
+static void linux_smbios_shutdown ( int booting __unused ) {
+
+       /* Clear SMBIOS data pointer */
+       smbios_clear();
+
+       /* Free SMBIOS data */
+       ufree ( smbios_data );
+}
+
+/** SMBIOS shutdown function */
+struct startup_fn linux_smbios_startup_fn __startup_fn ( STARTUP_NORMAL ) = {
+       .name = "linux_smbios",
+       .shutdown = linux_smbios_shutdown,
+};
+
 PROVIDE_SMBIOS ( linux, find_smbios, linux_find_smbios );

diff --git a/src/interface/smbios/smbios.c b/src/interface/smbios/smbios.c
index 5bd76f16a2ea9a7e5020333335d56a74105ba88c..12a080da22ae427e2ede259f5d98d124d8597e6a 100644 (file)
--- a/src/interface/smbios/smbios.c
+++ b/src/interface/smbios/smbios.c
@@ -255,3 +255,13 @@ int smbios_version ( void ) {
 
        return smbios.version;
 }
+
+/**
+ * Clear SMBIOS entry point descriptor
+ *
+ */
+void smbios_clear ( void ) {
+
+       /* Clear address */
+       smbios.address = UNULL;
+}