From: "Steven J. Hill" <Steven.Hill@xxxxxxxxxx>
Some MIPS controllers have hardware I/O coherency. This patch
detects those and turns off software coherency. A new kernel
command line option also allows the user to manually turn
software coherency on or off.
Signed-off-by: Steven J. Hill <Steven.Hill@xxxxxxxxxx>
---
arch/mips/include/asm/dma-mapping.h | 3 +
arch/mips/include/asm/mach-generic/dma-coherence.h | 5 +-
arch/mips/mm/c-r4k.c | 26 +++++---
arch/mips/mm/dma-default.c | 5 +-
arch/mips/mti-malta/malta-setup.c | 63 ++++++++++++++++++++
arch/mips/mti-sead3/sead3-setup.c | 3 -
6 files changed, 89 insertions(+), 16 deletions(-)
diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index f8fc74b..c8872ef 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -5,6 +5,9 @@
#include <asm/cache.h>
#include <asm-generic/dma-coherent.h>
+extern int coherentio;
+extern int hw_coherentio;
+
#ifndef CONFIG_SGI_IP27 /* Kludge to fix 2.6.39 build for IP27 */
#include <dma-coherence.h>
#endif
diff --git a/arch/mips/include/asm/mach-generic/dma-coherence.h b/arch/mips/include/asm/mach-generic/dma-coherence.h
index 9c95177..fe23034 100644
--- a/arch/mips/include/asm/mach-generic/dma-coherence.h
+++ b/arch/mips/include/asm/mach-generic/dma-coherence.h
@@ -61,9 +61,8 @@ static inline int plat_device_is_coherent(struct device *dev)
{
#ifdef CONFIG_DMA_COHERENT
return 1;
-#endif
-#ifdef CONFIG_DMA_NONCOHERENT
- return 0;
+#else
+ return coherentio;
#endif
}
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index b5aedb2..a4ec0e3 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1381,19 +1381,24 @@ static void __cpuinit coherency_setup(void)
}
}
-#if defined(CONFIG_DMA_NONCOHERENT)
-
-static int __cpuinitdata coherentio;
+int coherentio = 0; /* User defined DMA coherency from command line. */
+int hw_coherentio = 0; /* Actual hardware supported DMA coherency setting. */
static int __init setcoherentio(char *str)
{
coherentio = 1;
-
+ pr_info("Hardware DMA cache coherency (command line)\n");
return 0;
}
-
early_param("coherentio", setcoherentio);
-#endif
+
+static int __init setnocoherentio(char *str)
+{
+ coherentio = 0;
+ pr_info("Software DMA cache coherency (command line)\n");
+ return 0;
+}
+early_param("nocoherentio", setnocoherentio);
static void __cpuinit r4k_cache_error_setup(void)
{
@@ -1476,9 +1481,14 @@ void __cpuinit r4k_cache_init(void)
build_clear_page();
build_copy_page();
-#if !defined(CONFIG_MIPS_CMP)
+
+ /*
+ * We want to run CMP kernels on core with and without coherent
+ * caches. Therefore, do not use CONFIG_MIPS_CMP to decide whether
+ * or not to flush caches.
+ */
local_r4k___flush_cache_all(NULL);
-#endif
+
coherency_setup();
board_cache_error_setup = r4k_cache_error_setup;
}
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index f9ef838..72ee4fe 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -115,7 +115,8 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
if (!plat_device_is_coherent(dev)) {
dma_cache_wback_inv((unsigned long) ret, size);
- ret = UNCAC_ADDR(ret);
+ if (!hw_coherentio)
+ ret = UNCAC_ADDR(ret);
}
}
@@ -142,7 +143,7 @@ static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
- if (!plat_device_is_coherent(dev))
+ if (!plat_device_is_coherent(dev) && !hw_coherentio)
addr = CAC_ADDR(addr);
free_pages(addr, get_order(size));
diff --git a/arch/mips/mti-malta/malta-setup.c b/arch/mips/mti-malta/malta-setup.c
index 200f64d..a855571 100644
--- a/arch/mips/mti-malta/malta-setup.c
+++ b/arch/mips/mti-malta/malta-setup.c
@@ -32,6 +32,7 @@
#include <asm/mips-boards/maltaint.h>
#include <asm/dma.h>
#include <asm/traps.h>
+#include <asm/gcmpregs.h>
#ifdef CONFIG_VT
#include <linux/console.h>
#endif
@@ -105,6 +106,66 @@ static void __init fd_activate(void)
}
#endif
+static int __init plat_enable_iocoherency(void)
+{
+ int supported = 0;
+ if (mips_revision_sconid == MIPS_REVISION_SCON_BONITO) {
+ if (BONITO_PCICACHECTRL & BONITO_PCICACHECTRL_CPUCOH_PRES) {
+ BONITO_PCICACHECTRL |= BONITO_PCICACHECTRL_CPUCOH_EN;
+ pr_info("Enabled Bonito CPU coherency\n");
+ supported = 1;
+ }
+ if (strstr(fw_getcmdline(), "iobcuncached")) {
+ BONITO_PCICACHECTRL &= ~BONITO_PCICACHECTRL_IOBCCOH_EN;
+ BONITO_PCIMEMBASECFG = BONITO_PCIMEMBASECFG &
+ ~(BONITO_PCIMEMBASECFG_MEMBASE0_CACHED |
+ BONITO_PCIMEMBASECFG_MEMBASE1_CACHED);
+ pr_info("Disabled Bonito IOBC coherency\n");
+ } else {
+ BONITO_PCICACHECTRL |= BONITO_PCICACHECTRL_IOBCCOH_EN;
+ BONITO_PCIMEMBASECFG |=
+ (BONITO_PCIMEMBASECFG_MEMBASE0_CACHED |
+ BONITO_PCIMEMBASECFG_MEMBASE1_CACHED);
+ pr_info("Enabled Bonito IOBC coherency\n");
+ }
+ } else if (gcmp_niocu() != 0) {
+ /* Nothing special needs to be done to enable coherency */
+ pr_info("CMP IOCU detected\n");
+ if ((*(unsigned int *)0xbf403000 & 0x81) != 0x81) {
+ pr_crit("IOCU OPERATION DISABLED BY SWITCH - DEFAULTING TO SW IO COHERENCY\n");
+ return 0;
+ }
+ supported = 1;
+ }
+ hw_coherentio = supported;
+ return supported;
+}
+
+static void __init plat_setup_iocoherency(void)
+{
+#ifdef CONFIG_DMA_NONCOHERENT
+ /*
+ * Kernel has been configured with software coherency
+ * but we might choose to turn it off and use hardware
+ * coherency instead.
+ */
+ if (plat_enable_iocoherency()) {
+ if (coherentio == 0)
+ pr_info("Hardware DMA cache coherency disabled\n");
+ else
+ pr_info("Hardware DMA cache coherency enabled\n");
+ } else {
+ if (coherentio == 1)
+ pr_info("Hardware DMA cache coherency unsupported, but enabled from command line!\n");
+ else
+ pr_info("Software DMA cache coherency enabled\n");
+ }
+#else
+ if (!plat_enable_iocoherency())
+ panic("Hardware DMA cache coherency not supported!");
+#endif
+}
+
#ifdef CONFIG_BLK_DEV_IDE
static void __init pci_clock_check(void)
{
@@ -207,6 +268,8 @@ void __init plat_mem_setup(void)
if (mips_revision_sconid == MIPS_REVISION_SCON_BONITO)
bonito_quirks_setup();
+ plat_setup_iocoherency();
+
#ifdef CONFIG_BLK_DEV_IDE
pci_clock_check();
#endif
diff --git a/arch/mips/mti-sead3/sead3-setup.c b/arch/mips/mti-sead3/sead3-setup.c
index f012fd1..14633bc 100644
--- a/arch/mips/mti-sead3/sead3-setup.c
+++ b/arch/mips/mti-sead3/sead3-setup.c
@@ -13,9 +13,6 @@
#include <asm/mips-boards/generic.h>
#include <asm/prom.h>
-int coherentio; /* 0 => no DMA cache coherency (may be set by user) */
-int hw_coherentio; /* 0 => no HW DMA cache coherency (reflects real HW) */
-
const char *get_system_type(void)
{
return "MIPS SEAD3";
--
1.7.9.5
