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Revision 80ef4464d5e27408685e609d389663aad46644b9 authored by Robert Richter on 20 March 2019, 18:57:23 UTC, committed by Joerg Roedel on 22 March 2019, 11:01:58 UTC 
iommu/iova: Fix tracking of recently failed iova address
 
If a 32 bit allocation request is too big to possibly succeed, it
early exits with a failure and then should never update max32_alloc_
size. This patch fixes current code, now the size is only updated if
the slow path failed while walking the tree. Without the fix the
allocation may enter the slow path again even if there was a failure
before of a request with the same or a smaller size.

Cc: <stable@vger.kernel.org> # 4.20+
Fixes: bee60e94a1e2 ("iommu/iova: Optimise attempts to allocate iova from 32bit address range")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
1 parent 4e50ce0
Raw File
pswalk.c 
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: pswalk - Parser routines to walk parsed op tree(s)
 *
 * Copyright (C) 2000 - 2019, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acparser.h"

#define _COMPONENT          ACPI_PARSER
ACPI_MODULE_NAME("pswalk")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_delete_parse_tree
 *
 * PARAMETERS:  subtree_root        - Root of tree (or subtree) to delete
 *
 * RETURN:      None
 *
 * DESCRIPTION: Delete a portion of or an entire parse tree.
 *
 ******************************************************************************/
#include "amlcode.h"
void acpi_ps_delete_parse_tree(union acpi_parse_object *subtree_root)
{
	union acpi_parse_object *op = subtree_root;
	union acpi_parse_object *next = NULL;
	union acpi_parse_object *parent = NULL;
	u32 level = 0;

	ACPI_FUNCTION_TRACE_PTR(ps_delete_parse_tree, subtree_root);

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE_TREES, " root %p\n", subtree_root));

	/* Visit all nodes in the subtree */

	while (op) {
		if (op != parent) {

			/* This is the descending case */

			if (ACPI_IS_DEBUG_ENABLED
			    (ACPI_LV_PARSE_TREES, _COMPONENT)) {

				/* This debug option will print the entire parse tree */

				acpi_os_printf("      %*.s%s %p", (level * 4),
					       " ",
					       acpi_ps_get_opcode_name(op->
								       common.
								       aml_opcode),
					       op);

				if (op->named.aml_opcode == AML_INT_NAMEPATH_OP) {
					acpi_os_printf("  %4.4s",
						       op->common.value.string);
				}
				if (op->named.aml_opcode == AML_STRING_OP) {
					acpi_os_printf("  %s",
						       op->common.value.string);
				}
				acpi_os_printf("\n");
			}

			/* Look for an argument or child of the current op */

			next = acpi_ps_get_arg(op, 0);
			if (next) {

				/* Still going downward in tree (Op is not completed yet) */

				op = next;
				level++;
				continue;
			}
		}

		/* No more children, this Op is complete. */

		next = op->common.next;
		parent = op->common.parent;

		acpi_ps_free_op(op);

		/* If we are back to the starting point, the walk is complete. */

		if (op == subtree_root) {
			return_VOID;
		}

		if (next) {
			op = next;
		} else {
			level--;
			op = parent;
		}
	}

	return_VOID;
}
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