Re: [PATCH 00 of 14] swiotlb/x86: lay groundwork for xen dom0 use of swiotlb

Ingo Molnar
2008-12-16T20:35:47Z

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Hi Ingo,
>
> Here's some patches to clean up swiotlb to prepare for some Xen dom0
> patches. These have been posted before, but undergone a round of
> cleanups to address various comments.

applied to tip/core/iommu, thanks Jeremy.

the only patch that seems to have the potential to break drivers is:

be4ac7b: swiotlb: consistently use address_needs_mapping everywhere

looks fine to me, but the gents on the Cc: might have a dissenting
opinion?

Ingo

------------->
>From be4ac7b87b27380bc43fa4f686e39b46eca2c866 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Tue, 16 Dec 2008 12:17:28 -0800
Subject: [PATCH] swiotlb: consistently use address_needs_mapping everywhere

Impact: remove open-coded DMA mask assumptions

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
lib/swiotlb.c | 10 +++-------
1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index db724ba..76821f0 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -465,13 +465,9 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t dev_addr;
void *ret;
int order = get_order(size);
- u64 dma_mask = DMA_32BIT_MASK;
-
- if (hwdev && hwdev->coherent_dma_mask)
- dma_mask = hwdev->coherent_dma_mask;

ret = (void *)__get_free_pages(flags, order);
- if (ret && !is_buffer_dma_capable(dma_mask, virt_to_bus(ret), size)) {
+ if (ret && !address_needs_mapping(hwdev, virt_to_bus(ret), size)) {
/*
* The allocated memory isn't reachable by the device.
* Fall back on swiotlb_map_single().
@@ -495,9 +491,9 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dev_addr = virt_to_bus(ret);

/* Confirm address can be DMA'd by device */
- if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
+ if (!address_needs_mapping(hwdev, dev_addr, size)) {
printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
- (unsigned long long)dma_mask,
+ (unsigned long long)dma_get_mask(hwdev),
(unsigned long long)dev_addr);

/* DMA_TO_DEVICE to avoid memcpy in unmap_single */