[linux] Use generic sysfs mechanism to read ACPI tables

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

1 files changed, 21 insertions, 78 deletions

diff --git a/src/interface/linux/linux_acpi.c b/src/interface/linux/linux_acpi.c
index 08833d6..851cc54 100644
--- a/src/interface/linux/linux_acpi.c
+++ b/src/interface/linux/linux_acpi.c
@@ -23,9 +23,11 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <stdio.h>
 #include <errno.h>
 #include <ipxe/linux_api.h>
+#include <ipxe/linux_sysfs.h>
 #include <ipxe/linux.h>
 #include <ipxe/list.h>
 #include <ipxe/init.h>
+#include <ipxe/umalloc.h>
 #include <ipxe/acpi.h>
 
 /** ACPI sysfs directory */
@@ -40,7 +42,7 @@ struct linux_acpi_table {
 	/** Index */
 	unsigned int index;
 	/** Cached data */
-	void *data;
+	userptr_t data;
 };
 
 /** List of cached ACPI tables */
@@ -55,7 +57,6 @@ static LIST_HEAD ( linux_acpi_tables );
  */
 static userptr_t linux_acpi_find ( uint32_t signature, unsigned int index ) {
 	struct linux_acpi_table *table;
-	struct acpi_header header;
 	union {
 		uint32_t signature;
 		char filename[5];
@@ -63,16 +64,14 @@ static userptr_t linux_acpi_find ( uint32_t signature, unsigned int index ) {
 	static const char prefix[] = ACPI_SYSFS_PREFIX;
 	char filename[ sizeof ( prefix ) - 1 /* NUL */ + 4 /* signature */
 		       + 3 /* "999" */ + 1 /* NUL */ ];
-	ssize_t rlen;
-	size_t len;
-	void *data;
-	int fd;
+	int len;
+	int rc;
 
 	/* Check for existing table */
 	list_for_each_entry ( table, &linux_acpi_tables, list ) {
 		if ( ( table->signature == signature ) &&
 		     ( table->index == index ) )
-			return virt_to_user ( table->data );
+			return table->data;
 	}
 
 	/* Allocate a new table */
@@ -82,90 +81,34 @@ static userptr_t linux_acpi_find ( uint32_t signature, unsigned int index ) {
 	table->signature = signature;
 	table->index = index;
 
-	/* Construct filename */
+	/* Construct filename (including numeric suffix) */
 	memset ( &u, 0, sizeof ( u ) );
 	u.signature = le32_to_cpu ( signature );
 	snprintf ( filename, sizeof ( filename ), "%s%s%d", prefix,
 		   u.filename, ( index + 1 ) );
 
-	/* Open file */
-	fd = linux_open ( filename, O_RDONLY );
-	if ( ( fd < 0 ) && ( index == 0 ) ) {
+	/* Read file (with or without numeric suffix for index 0) */
+	len = linux_sysfs_read ( filename, &table->data );
+	if ( ( len < 0 ) && ( index == 0 ) ) {
 		filename[ sizeof ( prefix ) - 1 /* NUL */ +
 			  4 /* signature */ ] = '\0';
-		fd = linux_open ( filename, O_RDONLY );
+		len = linux_sysfs_read ( filename, &table->data );
 	}
-	if ( fd < 0 ) {
-		DBGC ( &linux_acpi_tables, "ACPI could not open %s: %s\n",
-		       filename, linux_strerror ( linux_errno ) );
-		goto err_open;
+	if ( len < 0 ) {
+		rc = len;
+		DBGC ( &linux_acpi_tables, "ACPI could not read %s: %s\n",
+		       filename, strerror ( rc ) );
+		goto err_read;
 	}
 
-	/* Read header */
-	rlen = linux_read ( fd, &header, sizeof ( header ) );
-	if ( rlen < 0 ) {
-		DBGC ( &linux_acpi_tables, "ACPI could not read %s header: "
-		       "%s\n", filename, linux_strerror ( linux_errno ) );
-		goto err_header;
-	}
-	if ( ( ( size_t ) rlen ) != sizeof ( header ) ) {
-		DBGC ( &linux_acpi_tables, "ACPI underlength %s header\n",
-		       filename );
-		goto err_header_len;
-	}
-
-	/* Parse header */
-	len = le32_to_cpu ( header.length );
-	if ( len < sizeof ( header ) ) {
-		DBGC ( &linux_acpi_tables, "ACPI malformed %s header\n",
-		       filename );
-		goto err_malformed;
-	}
-
-	/* Allocate data */
-	table->data = malloc ( len );
-	if ( ! table->data )
-		goto err_data;
-
-	/* Read table */
-	memcpy ( table->data, &header, sizeof ( header ) );
-	data = ( table->data + sizeof ( header ) );
-	len -= sizeof ( header );
-	while ( len ) {
-		rlen = linux_read ( fd, data, len );
-		if ( rlen < 0 ) {
-			DBGC ( &linux_acpi_tables, "ACPI could not read %s: "
-			       "%s\n", filename,
-			       linux_strerror ( linux_errno ) );
-			goto err_body;
-		}
-		if ( rlen == 0 ) {
-			DBGC ( &linux_acpi_tables, "ACPI underlength %s\n",
-			       filename );
-			goto err_body_len;
-		}
-		data += rlen;
-		len -= rlen;
-	}
-
-	/* Close file */
-	linux_close ( fd );
-
 	/* Add to list of tables */
 	list_add ( &table->list, &linux_acpi_tables );
 	DBGC ( &linux_acpi_tables, "ACPI cached %s\n", filename );
 
-	return virt_to_user ( table->data );
-
- err_body_len:
- err_body:
-	free ( table->data );
- err_data:
- err_malformed:
- err_header_len:
- err_header:
-	linux_close ( fd );
- err_open:
+	return table->data;
+
+	ufree ( table->data );
+ err_read:
 	free ( table );
  err_alloc:
 	return UNULL;
@@ -181,7 +124,7 @@ static void linux_acpi_shutdown ( int booting __unused ) {
 
 	list_for_each_entry_safe ( table, tmp, &linux_acpi_tables, list ) {
 		list_del ( &table->list );
-		free ( table->data );
+		ufree ( table->data );
 		free ( table );
 	}
 }