Hi Stany,
On 27/09/12 00:02, Stany MARCEL wrote:
Are cache flush needed as GFP_DMA flags are used for memory allocations
(kmalloc and skbuff) ?
Yes, you will still need to flush caches. Allocating with GFP_DMA means
that the memory you get is capable of being DMA'ed from and to.
Is not the responsibility of arch dependent file to allocate DMA'able memory
when this flag is used.
Its is DMA'able, but it is not normally cache coherent.
Regards
Greg
-----Original Message-----
From: Greg Ungerer [mailto:g...@snapgear.com]
Sent: Wed 9/26/2012 2:07 PM
To: uClinux development list
Cc: Philippe De Muyter; Stany MARCEL
Subject: Re: [uClinux-dev] [PATCH 3/3] m68knommu: Add ethernet driver for
MCF547x/MCF548x
On 09/26/2012 06:20 AM, Philippe De Muyter wrote:
Hello Stany
[CCing uclinux-dev]
On Tue, Sep 25, 2012 at 06:07:45PM +0200, Stany MARCEL wrote:
Hello Philippe,
I have to do the following modification to compile your drivers with MMU
enabled :
diff --git a/drivers/net/ethernet/freescale/fec_m54xx.c
b/drivers/net/ethernet/freescale/fec_m54xx.c
index 4204a14..f6cafc6 100644
--- a/drivers/net/ethernet/freescale/fec_m54xx.c
+++ b/drivers/net/ethernet/freescale/fec_m54xx.c
@@ -41,6 +41,10 @@
*/
#define flush_and_invalidate_dcache() flush_cache_all()
+#ifdef CONFIG_MMU
+#define flush_dcache_range(A, L) flush_cf_dcache(A, L)
Drivers shouldn't be calling these architecture flush functions at all.
They must use the DMA API and the functions it defines. See
Documentation/DMA-API.txt
For example look at the use of dma_map_single()/dma_unmap_single()
in drivers/net/ethernet/freescale/fec.c. (Ignore the almost certainly
bogus cache_flush_all() for CONFIG_M532x).
Regards
Greg
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: g...@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
8 Gardner Close, FAX: +61 7 3891 3630
Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com
--
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: g...@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
8 Gardner Close FAX: +61 7 3217 5323
Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com
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