From f78500d603664f4b6a14f381016457de415383c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Lov=C3=A9n?= <thomasloven@gmail.com>
Date: Fri, 29 Dec 2017 21:46:00 +0100
Subject: [PATCH] PMM -- Make sure stuff works even with V2P and P2V

---
 src/kernel/memory/pmm.c  |  2 +-
 src/kernel/memory/pmm.tt | 22 +++++++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/kernel/memory/pmm.c b/src/kernel/memory/pmm.c
index 5f1c679..f979351 100644
--- a/src/kernel/memory/pmm.c
+++ b/src/kernel/memory/pmm.c
@@ -13,6 +13,6 @@ uintptr_t pmm_alloc()
 {
   uintptr_t page = first;
   first = page?*(uintptr_t *)page:0;
-  page = (uintptr_t)V2P(page);
+  page = (uintptr_t)(page?V2P(page):0);
   return page;
 }
diff --git a/src/kernel/memory/pmm.tt b/src/kernel/memory/pmm.tt
index cb9b8e1..969009b 100644
--- a/src/kernel/memory/pmm.tt
+++ b/src/kernel/memory/pmm.tt
@@ -3,9 +3,9 @@
 
 #include <memory.h>
 #undef P2V
-#define P2V(addr) (void *)((uintptr_t)(addr))
+#define P2V(addr) ((void *)((uintptr_t)(addr)+1))
 #undef V2P
-#define V2P(addr) (void *)((uintptr_t)(addr))
+#define V2P(addr) ((uintptr_t)(addr)-1)
 #include "pmm.c"
 
 struct {
@@ -14,9 +14,9 @@ struct {
 
 TEST(alloc_returns_freed_page)
 {
-  pmm_free((uintptr_t)&mem[0]);
+  pmm_free(V2P(&mem[0]));
   uintptr_t a = pmm_alloc();
-  ASSERT_EQ_PTR(a, &mem[0]);
+  ASSERT_EQ_PTR(a, V2P(&mem[0]));
 }
 TEST(alloc_returns_0_if_no_free_pages)
 {
@@ -25,7 +25,7 @@ TEST(alloc_returns_0_if_no_free_pages)
 }
 TEST(alloc_zero_after_all_free_pages)
 {
-  pmm_free((uintptr_t)&mem[0]);
+  pmm_free(V2P(&mem[0]));
   pmm_alloc();
   uintptr_t a = pmm_alloc();
   ASSERT_EQ_PTR(a, 0);
@@ -33,24 +33,24 @@ TEST(alloc_zero_after_all_free_pages)
 
 TEST(alloc_two_pages___first_page_is_not_zero)
 {
-  pmm_free((uintptr_t)&mem[0]);
-  pmm_free((uintptr_t)&mem[1]);
+  pmm_free(V2P(&mem[0]));
+  pmm_free(V2P(&mem[1]));
   uintptr_t a = pmm_alloc();
   pmm_alloc();
   ASSERT_NEQ_PTR(a, 0);
 }
 TEST(alloc_two_pages___second_page_is_not_zero)
 {
-  pmm_free((uintptr_t)&mem[0]);
-  pmm_free((uintptr_t)&mem[1]);
+  pmm_free(V2P(&mem[0]));
+  pmm_free(V2P(&mem[1]));
   pmm_alloc();
   uintptr_t a = pmm_alloc();
   ASSERT_NEQ_PTR(a, 0);
 }
 TEST(alloc_two_pages___doesnt_return_same_page_twice)
 {
-  pmm_free((uintptr_t)&mem[0]);
-  pmm_free((uintptr_t)&mem[1]);
+  pmm_free(V2P(&mem[0]));
+  pmm_free(V2P(&mem[1]));
   uintptr_t a = pmm_alloc();
   uintptr_t b = pmm_alloc();
   ASSERT_NEQ_PTR(a, b);