On Tue, 2014-07-29 at 11:15 -0400, Mark Salter wrote: > On Tue, 2014-07-29 at 12:49 +0200, Ard Biesheuvel wrote: > > From: Mark Rutland <[email protected]> > > > > In certain cases the cpu-release-addr of a CPU may not fall in the > > linear mapping (e.g. when the kernel is loaded above this address due to > > the presence of other images in memory). This is problematic for the > > spin-table code as it assumes that it can trivially convert a > > cpu-release-addr to a valid VA in the linear map. > > > > This patch modifies the spin-table code to use a temporary cached > > mapping to write to a given cpu-release-addr, enabling us to support > > addresses regardless of whether they are covered by the linear mapping. > > > > Signed-off-by: Mark Rutland <[email protected]>
Oops, forgot: Tested-by: Mark Salter <[email protected]> > > --- > > arch/arm64/kernel/smp_spin_table.c | 21 ++++++++++++++++----- > > 1 file changed, 16 insertions(+), 5 deletions(-) > > > > diff --git a/arch/arm64/kernel/smp_spin_table.c > > b/arch/arm64/kernel/smp_spin_table.c > > index 0347d38eea29..70181c1bf42d 100644 > > --- a/arch/arm64/kernel/smp_spin_table.c > > +++ b/arch/arm64/kernel/smp_spin_table.c > > @@ -20,6 +20,7 @@ > > #include <linux/init.h> > > #include <linux/of.h> > > #include <linux/smp.h> > > +#include <linux/types.h> > > > > #include <asm/cacheflush.h> > > #include <asm/cpu_ops.h> > > @@ -65,12 +66,21 @@ static int smp_spin_table_cpu_init(struct device_node > > *dn, unsigned int cpu) > > > > static int smp_spin_table_cpu_prepare(unsigned int cpu) > > { > > - void **release_addr; > > + __le64 __iomem *release_addr; > > > > if (!cpu_release_addr[cpu]) > > return -ENODEV; > > > > - release_addr = __va(cpu_release_addr[cpu]); > > + /* > > + * The cpu-release-addr may or may not be inside the linear mapping. > > + * As ioremap_cache will either give us a new mapping or reuse the > > + * existing linear mapping, we can use it to cover both cases. In > > + * either case the memory will be MT_NORMAL. > > + */ > > + release_addr = ioremap_cache(cpu_release_addr[cpu], > > + sizeof(*release_addr)); > > + if (!release_addr) > > + return -ENOMEM; > > > > /* > > * We write the release address as LE regardless of the native > > @@ -79,15 +89,16 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu) > > * boot-loader's endianess before jumping. This is mandated by > > * the boot protocol. > > */ > > - release_addr[0] = (void *) cpu_to_le64(__pa(secondary_holding_pen)); > > - > > - __flush_dcache_area(release_addr, sizeof(release_addr[0])); > > + writeq_relaxed(__pa(secondary_holding_pen), release_addr); > > + __flush_dcache_area(release_addr, sizeof(*release_addr)); > > __flush_dcache_area((__force void *)release_addr, ... > > to avoid sparse warning. > > > > > /* > > * Send an event to wake up the secondary CPU. > > */ > > sev(); > > > > + iounmap(release_addr); > > + > > return 0; > > } > > > -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
