MIPS: Sanitise coherentio semantics

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

View file

@ -48,17 +48,17 @@ void __init plat_mem_setup(void)
clear_c0_config(1 << 19); /* Clear Config[OD] */
hw_coherentio = 0;
coherentio = 1;
coherentio = IO_COHERENCE_ENABLED;
switch (alchemy_get_cputype()) {
case ALCHEMY_CPU_AU1000:
case ALCHEMY_CPU_AU1500:
case ALCHEMY_CPU_AU1100:
coherentio = 0;
coherentio = IO_COHERENCE_DISABLED;
break;
case ALCHEMY_CPU_AU1200:
/* Au1200 AB USB does not support coherent memory */
if (0 == (read_c0_prid() & PRID_REV_MASK))
coherentio = 0;
coherentio = IO_COHERENCE_DISABLED;
break;
}

View file

@ -9,14 +9,20 @@
#ifndef __ASM_DMA_COHERENCE_H
#define __ASM_DMA_COHERENCE_H
enum coherent_io_user_state {
IO_COHERENCE_DEFAULT,
IO_COHERENCE_ENABLED,
IO_COHERENCE_DISABLED,
};
#ifdef CONFIG_DMA_MAYBE_COHERENT
extern int coherentio;
extern enum coherent_io_user_state coherentio;
extern int hw_coherentio;
#else
#ifdef CONFIG_DMA_COHERENT
#define coherentio 1
#define coherentio IO_COHERENCE_ENABLED
#else
#define coherentio 0
#define coherentio IO_COHERENCE_DISABLED
#endif
#define hw_coherentio 0
#endif /* CONFIG_DMA_MAYBE_COHERENT */

View file

@ -49,7 +49,15 @@ static inline int plat_dma_supported(struct device *dev, u64 mask)
static inline int plat_device_is_coherent(struct device *dev)
{
return coherentio;
switch (coherentio) {
default:
case IO_COHERENCE_DEFAULT:
return hw_coherentio;
case IO_COHERENCE_ENABLED:
return 1;
case IO_COHERENCE_DISABLED:
return 0;
}
}
#ifndef plat_post_dma_flush

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;

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;
}

View file

@ -154,12 +154,12 @@ static void __init plat_setup_iocoherency(void)
* coherency instead.
*/
if (plat_enable_iocoherency()) {
if (coherentio == 0)
if (coherentio == IO_COHERENCE_DISABLED)
pr_info("Hardware DMA cache coherency disabled\n");
else
pr_info("Hardware DMA cache coherency enabled\n");
} else {
if (coherentio == 1)
if (coherentio == IO_COHERENCE_ENABLED)
pr_info("Hardware DMA cache coherency unsupported, but enabled from command line!\n");
else
pr_info("Software DMA cache coherency enabled\n");

View file

@ -429,7 +429,8 @@ static int alchemy_pci_probe(struct platform_device *pdev)
/* Au1500 revisions older than AD have borked coherent PCI */
if ((alchemy_get_cputype() == ALCHEMY_CPU_AU1500) &&
(read_c0_prid() < 0x01030202) && !coherentio) {
(read_c0_prid() < 0x01030202) &&
(coherentio == IO_COHERENCE_DISABLED)) {
val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
val |= PCI_CONFIG_NC;
__raw_writel(val, ctx->regs + PCI_REG_CONFIG);