diff options
| author | Steven J. Hill <Steven.Hill@imgtec.com> | 2013-03-25 13:47:29 -0500 |
|---|---|---|
| committer | Steven J. Hill <Steven.Hill@imgtec.com> | 2013-05-01 16:32:49 -0500 |
| commit | b6d92b4a6bdb880b39789c677b952c53a437028d (patch) | |
| tree | f14d30f02314d75860aa1ed12449410e6659513b /arch/mips/mti-malta | |
| parent | c34c09c81d659e13e15947580198fa652af3ca1a (diff) | |
MIPS: Add option to disable software I/O coherency.
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@imgtec.com>
Diffstat (limited to 'arch/mips/mti-malta')
| -rw-r--r-- | arch/mips/mti-malta/malta-setup.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/mips/mti-malta/malta-setup.c b/arch/mips/mti-malta/malta-setup.c index 200f64df2c9..a85557171fa 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 |