Messages in this thread | | | Date | Fri, 07 Feb 2020 10:24:19 -0800 (PST) | From | Palmer Dabbelt <> | Subject | Re: [PATCH v4 2/2] riscv: Add support to determine no. of L2 cache way enabled |
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On Thu, 16 Jan 2020 23:43:38 PST (-0800), yash.shah@sifive.com wrote: > In order to determine the number of L2 cache ways enabled at runtime, > implement a private attribute ("number_of_ways_enabled"). Reading this > attribute returns the number of enabled L2 cache ways at runtime. > > Using riscv_set_cacheinfo_ops() hook a custom function, that returns > this private attribute, to the generic ops structure which is used by > cache_get_priv_group() in cacheinfo framework. > > Signed-off-by: Yash Shah <yash.shah@sifive.com> > Reviewed-by: Anup Patel <anup@brainfault.org> > --- > drivers/soc/sifive/sifive_l2_cache.c | 38 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/drivers/soc/sifive/sifive_l2_cache.c b/drivers/soc/sifive/sifive_l2_cache.c > index a506939..3fb6404 100644 > --- a/drivers/soc/sifive/sifive_l2_cache.c > +++ b/drivers/soc/sifive/sifive_l2_cache.c > @@ -9,6 +9,8 @@ > #include <linux/interrupt.h> > #include <linux/of_irq.h> > #include <linux/of_address.h> > +#include <linux/device.h> > +#include <asm/cacheinfo.h> > #include <soc/sifive/sifive_l2_cache.h> > > #define SIFIVE_L2_DIRECCFIX_LOW 0x100 > @@ -31,6 +33,7 @@ > > static void __iomem *l2_base; > static int g_irq[SIFIVE_L2_MAX_ECCINTR]; > +static struct riscv_cacheinfo_ops l2_cache_ops; > > enum { > DIR_CORR = 0, > @@ -107,6 +110,38 @@ int unregister_sifive_l2_error_notifier(struct notifier_block *nb) > } > EXPORT_SYMBOL_GPL(unregister_sifive_l2_error_notifier); > > +static int l2_largest_wayenabled(void) > +{ > + return readl(l2_base + SIFIVE_L2_WAYENABLE); > +}
WayEnable is 8 bits.
> + > +static ssize_t number_of_ways_enabled_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return sprintf(buf, "%u\n", l2_largest_wayenabled()); > +} > + > +static DEVICE_ATTR_RO(number_of_ways_enabled); > + > +static struct attribute *priv_attrs[] = { > + &dev_attr_number_of_ways_enabled.attr, > + NULL, > +}; > + > +static const struct attribute_group priv_attr_group = { > + .attrs = priv_attrs, > +}; > + > +const struct attribute_group *l2_get_priv_group(struct cacheinfo *this_leaf) > +{ > + /* We want to use private group for L2 cache only */ > + if (this_leaf->level == 2) > + return &priv_attr_group; > + else > + return NULL; > +} > + > static irqreturn_t l2_int_handler(int irq, void *device) > { > unsigned int add_h, add_l; > @@ -170,6 +205,9 @@ static int __init sifive_l2_init(void) > > l2_config_read(); > > + l2_cache_ops.get_priv_group = l2_get_priv_group; > + riscv_set_cacheinfo_ops(&l2_cache_ops); > + > #ifdef CONFIG_DEBUG_FS > setup_sifive_debug(); > #endif
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