From: Alan Cox <alan@linux.intel.com>
Date: Sat, 21 Oct 2017 12:44:15 +0000 (+0100)
Subject: 8086: add copy_fork helper
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=0902e33868b647c5d246db046ccf4a8cfd85a703;p=FUZIX.git

8086: add copy_fork helper

The banking code needs to own this because it owns the mapping sizes and
already needs the same copiers to move pages around.
---

diff --git a/Kernel/bank8086.c b/Kernel/bank8086.c
index 59cb6276..bfc153c5 100644
--- a/Kernel/bank8086.c
+++ b/Kernel/bank8086.c
@@ -216,7 +216,7 @@ static int do_process_create(uint8_t csize, uint8_t dsize, uint8_t ssize)
 #endif	
 	m->cbase = alloc_code(csize);
 	if (m->cbase == 0) {
-#ifdef COFNIG_IBMPC_EMM	
+#ifdef COFNIG_IBMPC_EMM
 		emm_free_bank(m);
 #endif		
 		return -1;
@@ -299,7 +299,7 @@ static int stack_fault(uint8_t ssize)
 	/* Collided ? if so we will wrap */
 	if (m->ssize + m->dsize > m->ssize)
 		return ENOMEM;
-#ifdef CONFIG_IBMPC_EMM		
+#ifdef CONFIG_IBMPC_EMM
 	if (m->emm) {
 		m->ssize = ssize;
 		return 0;
@@ -443,6 +443,26 @@ void pagemap_free(ptptr p)
 	claim_regions(m, 0);
 }
 
+void fork_copy(ptptr p)
+{
+	struct proc_map *parent_m = (struct proc_map *)udata.u_page2;
+	struct proc_map *child_m = (struct proc_map *)p->p_page2;
+	/* udata is the parent ptptr p is the child */
+#ifdef CONFIG_IBMPC_EMM
+	if (emm) {
+		/* This one is hard as both might be EMM so we'll need to do
+		   a pair of 32K/32K mappings to copy them over */
+		emm_copy_data_pages(parent_m, child_m);
+	}
+	else
+#endif
+	copy_pages(child->m_dbase, parent->m_dbase, parent->m_dsize);
+	/* This last one will need to be reworked once we've got shared
+	   code segments */
+	copy_pages(child->m_cbase, parent->m_cbase, parent->m_csize);
+}
+
+
 #ifdef CONFIG_SWAP
 
 int swapout(ptptr p)