[PATCH 099/108] x86: Sort the MTRR table

Simon Glass sjg at chromium.org
Mon Jan 27 06:06:46 CET 2020


At present the MTRR registers are programmed with the list the U-Boot
builds up in the same order. In some cases this list may be out of order.
It looks better in Linux to have the registers in order, so sort them,

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 arch/x86/cpu/mtrr.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/x86/cpu/mtrr.c b/arch/x86/cpu/mtrr.c
index a43cb7fc15..5a4eb648fb 100644
--- a/arch/x86/cpu/mtrr.c
+++ b/arch/x86/cpu/mtrr.c
@@ -18,6 +18,7 @@
 
 #include <common.h>
 #include <cpu_func.h>
+#include <sort.h>
 #include <asm/io.h>
 #include <asm/msr.h>
 #include <asm/mtrr.h>
@@ -61,6 +62,16 @@ static void set_var_mtrr(uint reg, uint type, uint64_t start, uint64_t size)
 	wrmsrl(MTRR_PHYS_MASK_MSR(reg), mask | MTRR_PHYS_MASK_VALID);
 }
 
+static int h_comp_mtrr(const void *p1, const void *p2)
+{
+	const struct mtrr_request *req1 = p1;
+	const struct mtrr_request *req2 = p2;
+
+	s64 diff = req1->start - req2->start;
+
+	return diff < 0 ? -1 : diff > 0 ? 1 : 0;
+}
+
 int mtrr_commit(bool do_caches)
 {
 	struct mtrr_request *req = gd->arch.mtrr_req;
@@ -75,6 +86,7 @@ int mtrr_commit(bool do_caches)
 	debug("open\n");
 	mtrr_open(&state, do_caches);
 	debug("open done\n");
+	qsort(req, gd->arch.mtrr_req_count, sizeof(*req), h_comp_mtrr);
 	for (i = 0; i < gd->arch.mtrr_req_count; i++, req++)
 		set_var_mtrr(i, req->type, req->start, req->size);
 
-- 
2.25.0.341.g760bfbb309-goog



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