xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

MIPS: Sanitise coherentio semantics

Browse Source 
The coherentio variable has previously been used as a boolean value,
indicating whether the user specified that coherent I/O should be
enabled or disabled. It failed to take into account the case where the
user does not specify any preference, in which case it makes sense that
we should default to coherent I/O if the hardware supports it
(hw_coherentio is non-zero).

Introduce an enum to clarify the 3 different values of coherentio & use
it throughout the code, modifying plat_device_is_coherent() &
r4k_cache_init() to take into account the default case.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/14347/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Paul Burton
2016-10-05 18:18:14 +01:00
committed by Ralf Baechle
parent 87dd9a4de4
commit f23020230e
7 changed files with 31 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
arch/mips/mm/c-r4k.c
View File

@@ -1935,7 +1935,8 @@ void r4k_cache_init(void)
__local_flush_icache_user_range = local_r4k_flush_icache_user_range;
#if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
if (coherentio) {
if ((coherentio == IO_COHERENCE_ENABLED) ||
((coherentio == IO_COHERENCE_DEFAULT) && hw_coherentio)) {
_dma_cache_wback_inv = (void *)cache_noop;
_dma_cache_wback = (void *)cache_noop;
_dma_cache_inv = (void *)cache_noop;

7
arch/mips/mm/dma-default.c
View File

@@ -25,13 +25,14 @@
#include <dma-coherence.h>
#ifdef CONFIG_DMA_MAYBE_COHERENT
int coherentio = 0; /* User defined DMA coherency from command line. */
/* User defined DMA coherency from command line. */
enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
EXPORT_SYMBOL_GPL(coherentio);
int hw_coherentio = 0; /* Actual hardware supported DMA coherency setting. */
static int __init setcoherentio(char *str)
{
coherentio = 1;
coherentio = IO_COHERENCE_ENABLED;
pr_info("Hardware DMA cache coherency (command line)\n");
return 0;
}
@@ -39,7 +40,7 @@ early_param("coherentio", setcoherentio);
static int __init setnocoherentio(char *str)
{
coherentio = 0;
coherentio = IO_COHERENCE_DISABLED;
pr_info("Software DMA cache coherency (command line)\n");
return 0;
}