| Message ID | 20250317070124.815028-1-ming.li@zohomail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/1] cxl/region: Fix the first aliased address miscalculation | expand |
On Mon, Mar 17, 2025 at 03:01:24PM +0800, Li Ming wrote: > In extended linear cache(ELC) case, cxl_port_get_spa_cache_alias() helps > to get the aliased address of a SPA, it considers the first address in > CXL memory range is "region start + region cache size + 1", but it > should be "region start + region cache size". > > So if a SPA is equal to "region start + region cache size", its aliased > address should be "SPA - region cache size". Nice catch Ming! Reviewed-by: Alison Schofield <alison.schofield@intel.com> > > Signed-off-by: Li Ming <ming.li@zohomail.com> > --- > drivers/cxl/core/region.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 6d8bdb53f258..c3f4dc244df7 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -3460,7 +3460,7 @@ u64 cxl_port_get_spa_cache_alias(struct cxl_port *endpoint, u64 spa) > if (!p->cache_size) > return ~0ULL; > > - if (spa > p->res->start + p->cache_size) > + if (spa >= p->res->start + p->cache_size) > return spa - p->cache_size; > > return spa + p->cache_size; > -- > 2.34.1 >
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 6d8bdb53f258..c3f4dc244df7 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3460,7 +3460,7 @@ u64 cxl_port_get_spa_cache_alias(struct cxl_port *endpoint, u64 spa) if (!p->cache_size) return ~0ULL; - if (spa > p->res->start + p->cache_size) + if (spa >= p->res->start + p->cache_size) return spa - p->cache_size; return spa + p->cache_size;
In extended linear cache(ELC) case, cxl_port_get_spa_cache_alias() helps to get the aliased address of a SPA, it considers the first address in CXL memory range is "region start + region cache size + 1", but it should be "region start + region cache size". So if a SPA is equal to "region start + region cache size", its aliased address should be "SPA - region cache size". Signed-off-by: Li Ming <ming.li@zohomail.com> --- drivers/cxl/core/region.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)