diff options
| -rw-r--r-- | Documentation/devicetree/bindings/arm/l2cc.txt | 10 | ||||
| -rw-r--r-- | arch/arm/mm/cache-l2x0.c | 121 |
2 files changed, 131 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt index af527ee111c..292ef7ca305 100644 --- a/Documentation/devicetree/bindings/arm/l2cc.txt +++ b/Documentation/devicetree/bindings/arm/l2cc.txt @@ -2,6 +2,10 @@ ARM cores often have a separate level 2 cache controller. There are various implementations of the L2 cache controller with compatible programming models. +Some of the properties that are just prefixed "cache-*" are taken from section +3.7.3 of the ePAPR v1.1 specification which can be found at: +https://www.power.org/wp-content/uploads/2012/06/Power_ePAPR_APPROVED_v1.1.pdf + The ARM L2 cache representation in the device tree should be done as follows: Required properties: @@ -44,6 +48,12 @@ Optional properties: I/O coherent mode. Valid only when the arm,pl310-cache compatible string is used. - interrupts : 1 combined interrupt. +- cache-size : specifies the size in bytes of the cache +- cache-sets : specifies the number of associativity sets of the cache +- cache-block-size : specifies the size in bytes of a cache block +- cache-line-size : specifies the size in bytes of a line in the cache, + if this is not specified, the line size is assumed to be equal to the + cache block size - cache-id-part: cache id part number to be used if it is not present on hardware - wt-override: If present then L2 is forced to Write through mode diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index 5f2c988a06a..55f9d6e0cc8 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -21,6 +21,7 @@ #include <linux/init.h> #include <linux/smp.h> #include <linux/spinlock.h> +#include <linux/log2.h> #include <linux/io.h> #include <linux/of.h> #include <linux/of_address.h> @@ -945,6 +946,98 @@ static int l2_wt_override; * pass it though the device tree */ static u32 cache_id_part_number_from_dt; +/** + * l2x0_cache_size_of_parse() - read cache size parameters from DT + * @np: the device tree node for the l2 cache + * @aux_val: pointer to machine-supplied auxilary register value, to + * be augmented by the call (bits to be set to 1) + * @aux_mask: pointer to machine-supplied auxilary register mask, to + * be augmented by the call (bits to be set to 0) + * @associativity: variable to return the calculated associativity in + * @max_way_size: the maximum size in bytes for the cache ways + */ +static void __init l2x0_cache_size_of_parse(const struct device_node *np, + u32 *aux_val, u32 *aux_mask, + u32 *associativity, + u32 max_way_size) +{ + u32 mask = 0, val = 0; + u32 cache_size = 0, sets = 0; + u32 way_size_bits = 1; + u32 way_size = 0; + u32 block_size = 0; + u32 line_size = 0; + + of_property_read_u32(np, "cache-size", &cache_size); + of_property_read_u32(np, "cache-sets", &sets); + of_property_read_u32(np, "cache-block-size", &block_size); + of_property_read_u32(np, "cache-line-size", &line_size); + + if (!cache_size || !sets) + return; + + /* All these l2 caches have the same line = block size actually */ + if (!line_size) { + if (block_size) { + /* If linesize if not given, it is equal to blocksize */ + line_size = block_size; + } else { + /* Fall back to known size */ + pr_warn("L2C OF: no cache block/line size given: " + "falling back to default size %d bytes\n", + CACHE_LINE_SIZE); + line_size = CACHE_LINE_SIZE; + } + } + + if (line_size != CACHE_LINE_SIZE) + pr_warn("L2C OF: DT supplied line size %d bytes does " + "not match hardware line size of %d bytes\n", + line_size, + CACHE_LINE_SIZE); + + /* + * Since: + * set size = cache size / sets + * ways = cache size / (sets * line size) + * way size = cache size / (cache size / (sets * line size)) + * way size = sets * line size + * associativity = ways = cache size / way size + */ + way_size = sets * line_size; + *associativity = cache_size / way_size; + + if (way_size > max_way_size) { + pr_err("L2C OF: set size %dKB is too large\n", way_size); + return; + } + + pr_info("L2C OF: override cache size: %d bytes (%dKB)\n", + cache_size, cache_size >> 10); + pr_info("L2C OF: override line size: %d bytes\n", line_size); + pr_info("L2C OF: override way size: %d bytes (%dKB)\n", + way_size, way_size >> 10); + pr_info("L2C OF: override associativity: %d\n", *associativity); + + /* + * Calculates the bits 17:19 to set for way size: + * 512KB -> 6, 256KB -> 5, ... 16KB -> 1 + */ + way_size_bits = ilog2(way_size >> 10) - 3; + if (way_size_bits < 1 || way_size_bits > 6) { + pr_err("L2C OF: cache way size illegal: %dKB is not mapped\n", + way_size); + return; + } + + mask |= L2C_AUX_CTRL_WAY_SIZE_MASK; + val |= (way_size_bits << L2C_AUX_CTRL_WAY_SIZE_SHIFT); + + *aux_val &= ~mask; + *aux_val |= val; + *aux_mask &= ~mask; +} + static void __init l2x0_of_parse(const struct device_node *np, u32 *aux_val, u32 *aux_mask) { @@ -952,6 +1045,7 @@ static void __init l2x0_of_parse(const struct device_node *np, u32 tag = 0; u32 dirty = 0; u32 val = 0, mask = 0; + u32 assoc; of_property_read_u32(np, "arm,tag-latency", &tag); if (tag) { @@ -974,6 +1068,15 @@ static void __init l2x0_of_parse(const struct device_node *np, val |= (dirty - 1) << L2X0_AUX_CTRL_DIRTY_LATENCY_SHIFT; } + l2x0_cache_size_of_parse(np, aux_val, aux_mask, &assoc, SZ_256K); + if (assoc > 8) { + pr_err("l2x0 of: cache setting yield too high associativity\n"); + pr_err("l2x0 of: %d calculated, max 8\n", assoc); + } else { + mask |= L2X0_AUX_CTRL_ASSOC_MASK; + val |= (assoc << L2X0_AUX_CTRL_ASSOC_SHIFT); + } + *aux_val &= ~mask; *aux_val |= val; *aux_mask &= ~mask; @@ -1021,6 +1124,7 @@ static void __init l2c310_of_parse(const struct device_node *np, u32 data[3] = { 0, 0, 0 }; u32 tag[3] = { 0, 0, 0 }; u32 filter[2] = { 0, 0 }; + u32 assoc; of_property_read_u32_array(np, "arm,tag-latency", tag, ARRAY_SIZE(tag)); if (tag[0] && tag[1] && tag[2]) @@ -1047,6 +1151,23 @@ static void __init l2c310_of_parse(const struct device_node *np, writel_relaxed((filter[0] & ~(SZ_1M - 1)) | L310_ADDR_FILTER_EN, l2x0_base + L310_ADDR_FILTER_START); } + + l2x0_cache_size_of_parse(np, aux_val, aux_mask, &assoc, SZ_512K); + switch (assoc) { + case 16: + *aux_val &= ~L2X0_AUX_CTRL_ASSOC_MASK; + *aux_val |= L310_AUX_CTRL_ASSOCIATIVITY_16; + *aux_mask &= ~L2X0_AUX_CTRL_ASSOC_MASK; + break; + case 8: + *aux_val &= ~L2X0_AUX_CTRL_ASSOC_MASK; + *aux_mask &= ~L2X0_AUX_CTRL_ASSOC_MASK; + break; + default: + pr_err("PL310 OF: cache setting yield illegal associativity\n"); + pr_err("PL310 OF: %d calculated, only 8 and 16 legal\n", assoc); + break; + } } static const struct l2c_init_data of_l2c310_data __initconst = { |