fs/pxe: drop the use of PKTBUF_SEG

Drop the use of a magic PKTBUF_SEG, and instead just have a high
memory buffer for each file, and a single lowmem buffer that we reuse
at will.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 28 insertions, 34 deletions

diff --git a/core/fs/pxe/pxe.c b/core/fs/pxe/pxe.c
index e58901d9..2f29343e 100644
--- a/core/fs/pxe/pxe.c
+++ b/core/fs/pxe/pxe.c
@@ -29,6 +29,9 @@ static uint32_t gpxe_funcs;
 static uint8_t uuid_dashes[] = {4, 2, 2, 2, 6, 0};
 int have_uuid = 0;
 
+/* Common receive buffer */
+static __lowmem char packet_buf[PKTBUF_SIZE] __aligned(16);
+
 const uint8_t TimeoutTable[] = {
     2, 2, 3, 3, 4, 5, 6, 7, 9, 10, 12, 15, 18, 21, 26, 31, 37, 44, 53, 64, 77,
     92, 110, 132, 159, 191, 229, 255, 255, 255, 255, 0
@@ -65,13 +68,10 @@ static void files_init(void)
 {
     int i;
     struct open_file_t *socket = Files;
-    uint16_t pktbuf = 0;
     uint16_t nextport = 49152;
 
     for (i = 0; i < MAX_OPEN; i++) {
-	socket->tftp_pktbuf = pktbuf;
 	socket->tftp_nextport = nextport;
-	pktbuf += PKTBUF_SIZE;
 	nextport++;
 	socket++;
     }
@@ -421,8 +421,7 @@ static void get_packet_gpxe(struct open_file_t *file)
 
     while (1) {
         file_read.FileHandle  = file->tftp_remoteport;
-        file_read.Buffer.offs = file->tftp_pktbuf;
-        file_read.Buffer.seg  = PKTBUF_SEG;
+        file_read.Buffer      = FAR_PTR(packet_buf);
         file_read.BufferSize  = PKTBUF_SIZE;
         err = pxe_call(PXENV_FILE_READ, &file_read);
         if (!err)  /* successed */
@@ -432,6 +431,8 @@ static void get_packet_gpxe(struct open_file_t *file)
 	    kaboom();
     }
 
+    memcpy(file->tftp_pktbuf, packet_buf, file_read.BufferSize);
+
     file->tftp_dataptr   = file->tftp_pktbuf;
     file->tftp_bytesleft = file_read.BufferSize;
     file->tftp_filepos  += file_read.BufferSize;
@@ -501,8 +502,7 @@ static void fill_buffer(struct open_file_t *file)
     timeout = *timeout_ptr++;
     oldtime = jiffies();
     while (timeout) {
-        udp_read.buffer.offs = file->tftp_pktbuf;
-        udp_read.buffer.seg  = PKTBUF_SEG;
+        udp_read.buffer      = FAR_PTR(packet_buf);
         udp_read.buffer_size = PKTBUF_SIZE;
         udp_read.src_ip      = file->tftp_remoteip;
         udp_read.dest_ip     = MyIP;
@@ -524,7 +524,7 @@ static void fill_buffer(struct open_file_t *file)
         if (udp_read.buffer_size < 4)  /* Bad size for a DATA packet */
             continue;
 
-        data = MK_PTR(PKTBUF_SEG, file->tftp_pktbuf);
+        data = packet_buf;
         if (*(uint16_t *)data != TFTP_DATA)    /* Not a data packet */
             continue;
 
@@ -556,7 +556,8 @@ static void fill_buffer(struct open_file_t *file)
     /* It's the packet we want.  We're also EOF if the size < blocksize */
     file->tftp_lastpkt = last_pkt;    /* Update last packet number */
     buffersize = udp_read.buffer_size - 4;  /* Skip TFTP header */
-    file->tftp_dataptr = file->tftp_pktbuf + 4;
+    memcpy(file->tftp_pktbuf, packet_buf + 4, buffersize);
+    file->tftp_dataptr = file->tftp_pktbuf;
     file->tftp_filepos += buffersize;
     file->tftp_bytesleft = buffersize;
     if (buffersize < file->tftp_blksize) {
@@ -600,7 +601,7 @@ static uint32_t pxe_getfssec(struct file *gfile, char *buf,
         if (chunk > file->tftp_bytesleft)
             chunk = file->tftp_bytesleft;
         file->tftp_bytesleft -= chunk;
-        memcpy(buf, MK_PTR(PKTBUF_SEG, file->tftp_dataptr), chunk);
+        memcpy(buf, file->tftp_dataptr, chunk);
 	file->tftp_dataptr += chunk;
         buf += chunk;
         bytes_read += chunk;
@@ -711,8 +712,7 @@ static void pxe_searchdir(const char *filename, struct file *file)
     if (path_type == PXE_URL) {
 	if (has_gpxe) {
 	    file_open.Status        = PXENV_STATUS_BAD_FUNC;
-	    file_open.FileName.offs = OFFS(rrq_packet_buf + 2);
-	    file_open.FileName.seg  = SEG(rrq_packet_buf + 2);
+	    file_open.FileName      = FAR_PTR(rrq_packet_buf + 2);
 	    err = pxe_call(PXENV_FILE_OPEN, &file_open);
 	    if (err)
 		goto done;
@@ -734,8 +734,7 @@ static void pxe_searchdir(const char *filename, struct file *file)
 
     open_file->tftp_remoteip = ip;
     tid = open_file->tftp_localport;   /* TID(local port No) */
-    udp_write.buffer.offs = OFFS(rrq_packet_buf);
-    udp_write.buffer.seg  = SEG(rrq_packet_buf);
+    udp_write.buffer    = FAR_PTR(rrq_packet_buf);
     udp_write.ip        = ip;
     udp_write.gw        = ((udp_write.ip ^ MyIP) & net_mask) ? gate_way : 0;
     udp_write.src_port  = tid;
@@ -761,12 +760,11 @@ static void pxe_searchdir(const char *filename, struct file *file)
     timeout = *timeout_ptr++;
     oldtime = jiffies();
     for (;;) {
-        buf = packet_buf;
-        udp_read.buffer.offs = OFFS_WRT(buf, 0);
-        udp_read.buffer.seg = 0;
-        udp_read.buffer_size = 2048;
-        udp_read.dest_ip = MyIP;
-        udp_read.d_port = tid;
+        buf                  = packet_buf;
+        udp_read.buffer      = FAR_PTR(buf);
+        udp_read.buffer_size = PKTBUF_SIZE;
+        udp_read.dest_ip     = MyIP;
+        udp_read.d_port      = tid;
         err = pxe_call(PXENV_UDP_READ, &udp_read);
         if (err) {
 	    uint32_t now = jiffies();
@@ -836,7 +834,7 @@ static void pxe_searchdir(const char *filename, struct file *file)
 
         open_file->tftp_bytesleft = buffersize;
         open_file->tftp_dataptr = open_file->tftp_pktbuf;
-        memcpy(MK_PTR(PKTBUF_SEG, open_file->tftp_pktbuf), data, buffersize);
+        memcpy(open_file->tftp_pktbuf, data, buffersize);
 	break;
 
     case TFTP_OACK:
@@ -1478,6 +1476,10 @@ static int pxe_fs_init(struct fs_info *fs)
     fs->sector_shift = fs->block_shift = TFTP_BLOCKSIZE_LG2;
     fs->sector_size  = fs->block_size  = 1 << TFTP_BLOCKSIZE_LG2;
 
+    /* This block size is actually arbitrary... */
+    fs->sector_shift = fs->block_shift = TFTP_BLOCKSIZE_LG2;
+    fs->sector_size  = fs->block_size  = 1 << TFTP_BLOCKSIZE_LG2;
+
     /* Initialize the Files structure */
     files_init();
 
diff --git a/core/fs/pxe/pxe.h b/core/fs/pxe/pxe.h
index f62fa7a7..a4d7d83b 100644
--- a/core/fs/pxe/pxe.h
+++ b/core/fs/pxe/pxe.h
@@ -1,6 +1,7 @@
 /* -----------------------------------------------------------------------
  *
  *   Copyright 1999-2008 H. Peter Anvin - All Rights Reserved
+ *   Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -28,8 +29,7 @@
 #define TFTP_PORT        htons(69)              /* Default TFTP port */
 #define TFTP_BLOCKSIZE_LG2 9
 #define TFTP_BLOCKSIZE  (1 << TFTP_BLOCKSIZE_LG2)
-#define PKTBUF_SEG      0x4000
-#define PKTBUF_SIZE     (65536 / MAX_OPEN)
+#define PKTBUF_SIZE     2048			/*  */
 
 #define is_digit(c)     (((c) >= '0') && ((c) <= '9'))
 #define major_ver(v)    (((v) >> 8) && 0xff)
@@ -149,12 +149,12 @@ struct open_file_t {
     uint32_t tftp_blksize;     /* Block size for this connection(*) */
     uint16_t tftp_bytesleft;   /* Unclaimed data bytes */
     uint16_t tftp_lastpkt;     /* Sequence number of last packet (NBO) */
-    uint16_t tftp_dataptr;     /* Pointer to available data */
+    char    *tftp_dataptr;     /* Pointer to available data */
     uint8_t  tftp_goteof;      /* 1 if the EOF packet received */
-    uint8_t  tftp_unused;      /* Currently unused */
+    uint8_t  tftp_unused[3];   /* Currently unused */
     /* These values are preinitialized and not zeroed on close */
     uint16_t tftp_nextport;    /* Next port number for this slot (HBO) */
-    uint16_t tftp_pktbuf;      /* Packet buffer offset */
+    char     tftp_pktbuf[PKTBUF_SIZE];
 } __attribute__ ((packed));
 
 /*
@@ -179,8 +179,6 @@ extern char boot_file[];
 extern char path_prefix[];
 extern char LocalDomain[];
 
-extern char packet_buf[];
-
 extern char IPOption[];
 extern char dot_quad_buf[];
 
diff --git a/core/pxelinux.asm b/core/pxelinux.asm
index a966a393..a53fead1 100644
--- a/core/pxelinux.asm
+++ b/core/pxelinux.asm
@@ -94,12 +94,6 @@ DHCPMagic	resb 1			; PXELINUX magic flags
                 global BOOTIFStr
 BOOTIFStr	resb 7			; Space for "BOOTIF="
 
-		section .bss16
-                global packet_buf
-		alignb 16
-packet_buf	resb 2048		; Transfer packet
-packet_buf_size	equ $-packet_buf
-
 		section .text16
 StackBuf	equ STACK_TOP-44	; Base of stack if we use our own
 StackHome	equ StackBuf