From abe523be7760231ed4d14ac695dc0f2e34f09e54 Mon Sep 17 00:00:00 2001
From: "Justin C. Miller" <justin@justin.cm>
Date: Sun, 20 Sep 2020 14:06:06 -0700
Subject: [PATCH] [kernel] Remove page_manager::map_pages

The last use of page_manager::map_pages was during loading of ELF
binaries. Switched to vm_space::allow instead.
---
 src/kernel/page_manager.cpp | 24 ------------------------
 src/kernel/page_manager.h   |  8 --------
 src/kernel/scheduler.cpp    | 18 +++++++-----------
 3 files changed, 7 insertions(+), 43 deletions(-)

diff --git a/src/kernel/page_manager.cpp b/src/kernel/page_manager.cpp
index 36ace69..f52081e 100644
--- a/src/kernel/page_manager.cpp
+++ b/src/kernel/page_manager.cpp
@@ -52,30 +52,6 @@ page_manager::dump_pml4(page_table *pml4, bool recurse)
 	pml4->dump(page_table::level::pml4, recurse);
 }
 
-void *
-page_manager::map_pages(uintptr_t address, size_t count, bool user, page_table *pml4)
-{
-	kassert(address, "Cannot call map_pages with 0 address");
-
-	void *ret = reinterpret_cast<void *>(address);
-	if (!pml4) pml4 = get_pml4();
-
-	while (count) {
-		uintptr_t phys = 0;
-		size_t n = m_frames.allocate(count, &phys);
-
-		log::info(logs::paging, "Paging in %d pages at p:%016lx to v:%016lx into %016lx table",
-				n, phys, address, pml4);
-
-		page_in(pml4, phys, address, n, user);
-
-		address += n * frame_size;
-		count -= n;
-	}
-
-	return ret;
-}
-
 void
 page_manager::check_needs_page(page_table *table, unsigned index, bool user)
 {
diff --git a/src/kernel/page_manager.h b/src/kernel/page_manager.h
index f1b15bb..00bb026 100644
--- a/src/kernel/page_manager.h
+++ b/src/kernel/page_manager.h
@@ -49,14 +49,6 @@ public:
 		__asm__ __volatile__ ( "mov %0, %%cr3" :: "r" (p) );
 	}
 
-	/// Allocate and map pages into virtual memory.
-	/// \arg address  The virtual address at which to map the pages
-	/// \arg count    The number of pages to map
-	/// \arg user     True is this memory is user-accessible
-	/// \arg pml4     The pml4 to map into - null for the current one
-	/// \returns      A pointer to the start of the mapped region
-	void * map_pages(uintptr_t address, size_t count, bool user = false, page_table *pml4 = nullptr);
-
 	/// Dump the given or current PML4 to the console
 	/// \arg pml4     The page table to use, null for the current one
 	/// \arg recurse  Whether to print sub-tables
diff --git a/src/kernel/scheduler.cpp b/src/kernel/scheduler.cpp
index e6c05f2..05c75eb 100644
--- a/src/kernel/scheduler.cpp
+++ b/src/kernel/scheduler.cpp
@@ -67,10 +67,8 @@ load_process_image(const void *image_start, size_t bytes, TCB *tcb)
 {
 	// We're now in the process space for this process, allocate memory for the
 	// process code and load it
-	page_manager *pager = page_manager::get();
-
-	thread *th = thread::from_tcb(tcb);
-	process &proc = th->parent();
+	process &proc = process::current();
+	vm_space &space = proc.space();
 
 	log::debug(logs::loader, "Loading task! ELF: %016lx [%d]", image_start, bytes);
 
@@ -87,18 +85,16 @@ load_process_image(const void *image_start, size_t bytes, TCB *tcb)
 
 		uintptr_t aligned = header->vaddr & ~(memory::frame_size - 1);
 		size_t size = (header->vaddr + header->mem_size) - aligned;
-		size_t pages = page_manager::page_count(size);
+		size_t pagesize = page_manager::page_count(size) * memory::frame_size;
 
 		log::debug(logs::loader, "  Loadable segment %02u: vaddr %016lx  size %016lx",
 			i, header->vaddr, header->mem_size);
 
 		log::debug(logs::loader, "         - aligned to: vaddr %016lx  pages %d",
-			aligned, pages);
+			aligned, pagesize >> 12);
 
-		void *mapped = pager->map_pages(aligned, pages, true);
-		kassert(mapped, "Tried to map userspace pages and failed!");
-
-		kutil::memset(mapped, 0, pages * memory::frame_size);
+		space.allow(aligned, pagesize, true);
+		kutil::memset(reinterpret_cast<void*>(aligned), 0, pagesize);
 	}
 
 	const unsigned section_count = image.section_count();
@@ -127,7 +123,7 @@ load_process_image(const void *image_start, size_t bytes, TCB *tcb)
 	extern channel *std_out;
 	init->output = proc.add_handle(std_out);
 
-	th->clear_state(thread::state::loading);
+	thread::current().clear_state(thread::state::loading);
 
 	uintptr_t entrypoint = image.entrypoint();
 	log::debug(logs::loader, "  Loaded! New thread rip: %016lx", entrypoint);