On Sun, Dec 15, 2013 at 08:14:25PM +0800, Huacai Chen wrote:
> Loongson-3 is a multi-core MIPS family CPU, it support MIPS64R2 fully.
> Loongson-3 has the same IMP field (0x6300) as Loongson-2.
>
> Loongson-3 has a hardware-maintained cache, system software doesn't
> need to maintain coherency.
>
> Loongson-3A is the first revision of Loongson-3, and it is the quad-
> core version of Loongson-2G. Loongson-3A has a simplified version named
> Loongson-2Gq, the main difference between Loongson-3A/2Gq is 3A has two
> HyperTransport controller but 2Gq has only one. HT0 is used for cross-
> chip interconnection and HT1 is used to link PCI bus. Therefore, 2Gq
> cannot support NUMA but 3A can. For software, Loongson-2Gq is simply
> identified as Loongson-3A.
>
> Exsisting Loongson family CPUs:
> Loongson-1: Loongson-1A, Loongson-1B, they are 32-bit MIPS CPUs.
> Loongson-2: Loongson-2E, Loongson-2F, Loongson-2G, they are 64-bit
> single-core MIPS CPUs.
> Loongson-3: Loongson-3A(including so-called Loongson-2Gq), they are
> 64-bit multi-core MIPS CPUs.
>
> Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
> Signed-off-by: Hongliang Tao <taohl@xxxxxxxxxx>
> Signed-off-by: Hua Yan <yanh@xxxxxxxxxx>
> ---
> arch/mips/include/asm/addrspace.h | 2 ++
> arch/mips/include/asm/cpu.h | 5 +++--
> arch/mips/include/asm/mach-loongson/spaces.h | 19 +++++++++++++++++++
> arch/mips/include/asm/module.h | 2 ++
> arch/mips/include/asm/pgtable-bits.h | 7 +++++++
> 5 files changed, 33 insertions(+), 2 deletions(-)
> create mode 100644 arch/mips/include/asm/mach-loongson/spaces.h
>
> diff --git a/arch/mips/include/asm/addrspace.h b/arch/mips/include/asm/addrspace.h
> index 3f74545..41c030e 100644
> --- a/arch/mips/include/asm/addrspace.h
> +++ b/arch/mips/include/asm/addrspace.h
> @@ -116,7 +116,9 @@
> #define K_CALG_UNCACHED 2
> #define K_CALG_NONCOHERENT 3
> #define K_CALG_COH_EXCL 4
> +#ifndef K_CALG_COH_SHAREABLE
> #define K_CALG_COH_SHAREABLE 5
> +#endif
> #define K_CALG_NOTUSED 6
> #define K_CALG_UNCACHED_ACCEL 7
>
> diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
> index d2035e1..7fffaf1 100644
> --- a/arch/mips/include/asm/cpu.h
> +++ b/arch/mips/include/asm/cpu.h
> @@ -224,6 +224,7 @@
> #define PRID_REV_LOONGSON1B 0x0020
> #define PRID_REV_LOONGSON2E 0x0002
> #define PRID_REV_LOONGSON2F 0x0003
> +#define PRID_REV_LOONGSON3A 0x0005
>
> /*
> * Older processors used to encode processor version and revision in two
> @@ -295,8 +296,8 @@ enum cpu_type_enum {
> * MIPS64 class processors
> */
> CPU_5KC, CPU_5KE, CPU_20KC, CPU_25KF, CPU_SB1, CPU_SB1A, CPU_LOONGSON2,
> - CPU_CAVIUM_OCTEON, CPU_CAVIUM_OCTEON_PLUS, CPU_CAVIUM_OCTEON2,
> - CPU_CAVIUM_OCTEON3, CPU_XLR, CPU_XLP,
> + CPU_LOONGSON3, CPU_CAVIUM_OCTEON, CPU_CAVIUM_OCTEON_PLUS,
> + CPU_CAVIUM_OCTEON2, CPU_CAVIUM_OCTEON3, CPU_XLR, CPU_XLP,
>
> CPU_LAST
> };
> diff --git a/arch/mips/include/asm/mach-loongson/spaces.h b/arch/mips/include/asm/mach-loongson/spaces.h
> new file mode 100644
> index 0000000..e32c9ad
> --- /dev/null
> +++ b/arch/mips/include/asm/mach-loongson/spaces.h
> @@ -0,0 +1,19 @@
> +#ifndef __ASM_MACH_LOONGSON_SPACES_H_
> +#define __ASM_MACH_LOONGSON_SPACES_H_
> +
> +#ifndef CAC_BASE
> +#if defined(CONFIG_64BIT)
> +#if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_CPU_LOONGSON3)
> +#define CAC_BASE _AC(0x9800000000000000, UL)
> +#else
> +#define CAC_BASE _AC(0xa800000000000000, UL)
> +#endif /* CONFIG_DMA_NONCOHERENT || CONFIG_CPU_LOONGSON3 */
> +#endif /* CONFIG_64BIT */
> +#endif /* CONFIG_CAC_BASE */
> +
The value for Loongson 3A is correct and correspond to the one in the user
manual. It comes from the fact that Loongson 3A only have cache and
coherency attribute 2 (uncached), 3 (cached) and 7 (uncached
accelerated), and not 5 like some other CPU have for cacheable coherent
exclusive on write. This is perfectly fine as only values 2 and 3 are
required, the others are available for implementation dependent use.
That said it's already the case for the Loongson 2E and 2F according to
their respective manuals, even if 3 is non coherent there. So it looks
like the wrong value is used for Loongson 2E and 2F, even though it
obviously work.
I therefore suggest to use 0x9800000000000000 for all 64-bit Loongson
CPUs and get rid of the #ifdefs that do not really make sense here.
> +#ifdef CONFIG_CPU_LOONGSON3
> +#define K_CALG_COH_SHAREABLE 3
> +#endif
> +
This is the same here, the value should be 3 for Loongson 2E, 2F and 3A
> +#include <asm/mach-generic/spaces.h>
> +#endif
> diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
> index 44b705d..c2edae3 100644
> --- a/arch/mips/include/asm/module.h
> +++ b/arch/mips/include/asm/module.h
> @@ -126,6 +126,8 @@ search_module_dbetables(unsigned long addr)
> #define MODULE_PROC_FAMILY "LOONGSON1 "
> #elif defined CONFIG_CPU_LOONGSON2
> #define MODULE_PROC_FAMILY "LOONGSON2 "
> +#elif defined CONFIG_CPU_LOONGSON3
> +#define MODULE_PROC_FAMILY "LOONGSON3 "
> #elif defined CONFIG_CPU_CAVIUM_OCTEON
> #define MODULE_PROC_FAMILY "OCTEON "
> #elif defined CONFIG_CPU_XLR
> diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h
> index 32aea48..6c1e99e 100644
> --- a/arch/mips/include/asm/pgtable-bits.h
> +++ b/arch/mips/include/asm/pgtable-bits.h
> @@ -235,6 +235,13 @@ static inline uint64_t pte_to_entrylo(unsigned long pte_val)
> #define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
> #define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)
>
> +#elif defined(CONFIG_CPU_LOONGSON3)
> +
> +#define _CACHE_UNCACHED (2<<_CACHE_SHIFT) /* LOONGSON */
> +#define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT) /* LOONGSON */
> +#define _CACHE_CACHABLE_COHERENT (3<<_CACHE_SHIFT) /* LOONGSON-3 */
> +#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT) /* LOONGSON */
> +
> #else
This is fine but you should probably add an explanation why the same
value is used for both coherent and non-coherent, like it is done a few
line above for SB1.
> #define _CACHE_CACHABLE_NO_WA (0<<_CACHE_SHIFT) /* R4600 only */
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurelien@xxxxxxxxxxx http://www.aurel32.net
