From 870ed93bb6c35e821031bbc3a3a297d0e60c67ab Mon Sep 17 00:00:00 2001

From: Laszlo Ersek <lersek@redhat.com>

Date: Mon, 22 Dec 2014 13:11:41 +0100

Subject: [PATCH 10/15] fw_cfg_mem: expose the "data_width" property with

 fw_cfg_init_mem_wide()

We rebase fw_cfg_init_mem() to the new function for compatibility with

current callers.

The behavior of the (big endian) multi-byte data reads is best shown

with a qtest session.  Here, we are reading the first six bytes of

the UUID

    $ arm-softmmu/qemu-system-arm -M virt -machine accel=qtest \

         -qtest stdio -uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8

>>> writew 0x9020008 0x0200

<<< OK

>>> readl 0x9020000

<<< OK 0x000000004600cb32

Remember this is big endian.  On big endian machines, it is stored

directly as 0x46 0x00 0xcb 0x32.

On a little endian machine, we have to first swap it, so that it becomes

0x32cb0046.  When written to memory, it becomes 0x46 0x00 0xcb 0x32

again.

Reading byte-by-byte works too, of course:

>>> readb 0x9020000

<<< OK 0x0000000000000038

>>> readb 0x9020000

<<< OK 0x00000000000000ec

Here only a single byte is read at a time, so they are read in order

similar to the 1-byte data port that is already in PPC and SPARC

machines.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Message-id: 1419250305-31062-8-git-send-email-pbonzini@redhat.com

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

(cherry picked from commit 6c87e3d5967a1d731b5f591a8f0ee6c319c14ca8)

---

 hw/nvram/fw_cfg.c         | 12 +++++++++---

 include/hw/nvram/fw_cfg.h |  2 ++

 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c

index 2950d68..fcdf821 100644

--- a/hw/nvram/fw_cfg.c

+++ b/hw/nvram/fw_cfg.c

@@ -663,14 +663,14 @@ FWCfgState *fw_cfg_init_io(uint32_t iobase)

     return FW_CFG(dev);

 }

-FWCfgState *fw_cfg_init_mem(hwaddr ctl_addr, hwaddr data_addr)

+FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr, hwaddr data_addr,

+                                 uint32_t data_width)

 {

     DeviceState *dev;

     SysBusDevice *sbd;

     dev = qdev_create(NULL, TYPE_FW_CFG_MEM);

-    qdev_prop_set_uint32(dev, "data_width",

-                         fw_cfg_data_mem_ops.valid.max_access_size);

+    qdev_prop_set_uint32(dev, "data_width", data_width);

     fw_cfg_init1(dev);

@@ -681,6 +681,12 @@ FWCfgState *fw_cfg_init_mem(hwaddr ctl_addr, hwaddr data_addr)

     return FW_CFG(dev);

 }

+FWCfgState *fw_cfg_init_mem(hwaddr ctl_addr, hwaddr data_addr)

+{

+    return fw_cfg_init_mem_wide(ctl_addr, data_addr,

+                                fw_cfg_data_mem_ops.valid.max_access_size);

+}

+

 FWCfgState *fw_cfg_find(void)

 {

diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h

index a99586e..6d8a8ac 100644

--- a/include/hw/nvram/fw_cfg.h

+++ b/include/hw/nvram/fw_cfg.h

@@ -80,6 +80,8 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data,

                          size_t len);

 FWCfgState *fw_cfg_init_io(uint32_t iobase);

 FWCfgState *fw_cfg_init_mem(hwaddr ctl_addr, hwaddr data_addr);

+FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr, hwaddr data_addr,

+                                 uint32_t data_width);

 FWCfgState *fw_cfg_find(void);

-- 

2.1.0