| Message ID | 1409659354-23553-8-git-send-email-linus.walleij@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tue, Sep 02, 2014 at 02:02:33PM +0200, Linus Walleij wrote: > The ARM RealView platforms comes with boot loaders that fail > to set up cache size, ways and associativity correctly. This > complements Florian's patch to set up cache size and sets from > the device tree with the possibility to set up associativity > on the L2C-220 cache variant. Do we need this? If we have the cache size, the number of sets, and the cache block size (cache line size) which are all ePAPR specified properties for a cache, then: number of cache blocks = cache size / cache block size ways of associativity = number of cache blocks / number of sets way size = cache block size * number of sets It's a tad annoying to have to convert between the two representations, but ePAPR decided on size, sets and block size rather than size and ways. See arch/powerpc/kernel/cacheinfo.c line 260 for the powerpc associativity calculations from these values.
diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt index d33ed2344c7e..94b02f704f1d 100644 --- a/Documentation/devicetree/bindings/arm/l2cc.txt +++ b/Documentation/devicetree/bindings/arm/l2cc.txt @@ -44,6 +44,7 @@ Optional properties: I/O coherent mode. Valid only when the arm,pl310-cache compatible string is used. - interrupts : 1 combined interrupt. +- cache-associativity : specifies the associativity of the cache - cache-size : specifies the size in bytes of the cache - cache-sets : specifies the number of associativity sets of the cache - cache-id-part: cache id part number to be used if it is not present diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index c735f792c3d5..ebed9638b96c 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -1007,6 +1007,7 @@ static void __init l2x0_of_parse(const struct device_node *np, u32 tag = 0; u32 dirty = 0; u32 val = 0, mask = 0; + u32 assoc = 0; of_property_read_u32(np, "arm,tag-latency", &tag); if (tag) { @@ -1029,6 +1030,16 @@ static void __init l2x0_of_parse(const struct device_node *np, val |= (dirty - 1) << L2X0_AUX_CTRL_DIRTY_LATENCY_SHIFT; } + of_property_read_u32(np, "cache-associativity", &assoc); + if (assoc) { + if (assoc > 8) { + pr_warn("L2C: associativity %d is too large\n", assoc); + } else { + mask |= L2X0_AUX_CTRL_ASSOC_MASK; + val |= (assoc << L2X0_AUX_CTRL_ASSOC_SHIFT); + } + } + l2x0_cache_size_of_parse(np, aux_val, aux_mask, SZ_256K); *aux_val &= ~mask;
The ARM RealView platforms comes with boot loaders that fail to set up cache size, ways and associativity correctly. This complements Florian's patch to set up cache size and sets from the device tree with the possibility to set up associativity on the L2C-220 cache variant. Cc: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- Documentation/devicetree/bindings/arm/l2cc.txt | 1 + arch/arm/mm/cache-l2x0.c | 11 +++++++++++ 2 files changed, 12 insertions(+)