amd64_edac: Add support for interleaved region swapping

On revC3 and revE Fam10h machines and later, non-interleaved graphics
framebuffer memory under the 16G mark can be swapped with a region
located at the bottom of memory so that the GPU can use the interleaved
region and thus two channels. Add support for that.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 7a7bd7785ed4..9ea1bb4a51e3 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1331,6 +1331,42 @@ static int f10_lookup_addr_in_dct(u64 in_addr, u32 nid, u8 dct)
         return cs_found;
 }
 
+/*
+ * See F2x10C. Non-interleaved graphics framebuffer memory under the 16G is
+ * swapped with a region located at the bottom of memory so that the GPU can use
+ * the interleaved region and thus two channels.
+ */
+static u64 f10_swap_interleaved_region(struct amd64_pvt *pvt, u64 sys_addr)
+{
+        u32 swap_reg, swap_base, swap_limit, rgn_size, tmp_addr;
+
+        if (boot_cpu_data.x86 == 0x10) {
+                /* only revC3 and revE have that feature */
+                if (boot_cpu_data.x86_model < 4 ||
+                    (boot_cpu_data.x86_model < 0xa &&
+                     boot_cpu_data.x86_mask < 3))
+                        return sys_addr;
+        }
+
+        amd64_read_dct_pci_cfg(pvt, SWAP_INTLV_REG, &swap_reg);
+
+        if (!(swap_reg & 0x1))
+                return sys_addr;
+
+        swap_base       = (swap_reg >> 3) & 0x7f;
+        swap_limit      = (swap_reg >> 11) & 0x7f;
+        rgn_size        = (swap_reg >> 20) & 0x7f;
+        tmp_addr        = sys_addr >> 27;
+
+        if (!(sys_addr >> 34) &&
+            (((tmp_addr >= swap_base) &&
+             (tmp_addr <= swap_limit)) ||
+             (tmp_addr < rgn_size)))
+                return sys_addr ^ (u64)swap_base << 27;
+
+        return sys_addr;
+}
+
 /* For a given @dram_range, check if @sys_addr falls within it. */
 static int f10_match_to_this_node(struct amd64_pvt *pvt, int range,
                                   u64 sys_addr, int *nid, int *chan_sel)
@@ -1352,6 +1388,8 @@ static int f10_match_to_this_node(struct amd64_pvt *pvt, int range,
             (intlv_sel != ((sys_addr >> 12) & intlv_en)))
                 return -EINVAL;
 
+        sys_addr = f10_swap_interleaved_region(pvt, sys_addr);
+
         dct_sel_base = dct_sel_baseaddr(pvt);
 
         /*