On Fri, Jul 17, 2020 at 11:17:18AM +0200, Peter Zijlstra wrote:
On Fri, Jul 17, 2020 at 12:20:51AM -0700, ira.weiny@intel.com wrote:
+void dev_access_disable(void) +{
- unsigned long flags;
- if (!static_branch_unlikely(&dev_protection_static_key))
return;- local_irq_save(flags);
- current->dev_page_access_ref--;
- if (current->dev_page_access_ref == 0)
if (!--current->dev_page_access_ref)
It's not my style but I'm ok with it.
pks_update_protection(dev_page_pkey, PKEY_DISABLE_ACCESS);- local_irq_restore(flags);
+} +EXPORT_SYMBOL_GPL(dev_access_disable);
+void dev_access_enable(void) +{
- unsigned long flags;
- if (!static_branch_unlikely(&dev_protection_static_key))
return;- local_irq_save(flags);
- /* 0 clears the PKEY_DISABLE_ACCESS bit, allowing access */
- if (current->dev_page_access_ref == 0)
pks_update_protection(dev_page_pkey, 0);- current->dev_page_access_ref++;
if (!current->dev_page_access_ref++)
Sure.
- local_irq_restore(flags);
+} +EXPORT_SYMBOL_GPL(dev_access_enable);
Also, you probably want something like:
static __always_inline devm_access_disable(void)
Yes that is better.
However, again Dan and I agree devm is not the right prefix here.
I've updated.
Thanks! Ira
{ if (static_branch_unlikely(&dev_protection_static_key)) __devm_access_disable(); }
static __always_inline devm_access_enable(void) { if (static_branch_unlikely(&dev_protection_static_key)) __devm_access_enable(); }