From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41684) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtjJz-00029l-5E for qemu-devel@nongnu.org; Tue, 03 Nov 2015 16:40:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZtjJu-0002Sh-28 for qemu-devel@nongnu.org; Tue, 03 Nov 2015 16:40:51 -0500 Received: from relay-06.andrew.cmu.edu ([128.2.157.21]:36069 helo=relay.andrew.cmu.edu) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtjJt-0002SD-Rz for qemu-devel@nongnu.org; Tue, 03 Nov 2015 16:40:45 -0500 From: "Gabriel L. Somlo" Date: Tue, 3 Nov 2015 16:40:41 -0500 Message-Id: <1446586842-21793-6-git-send-email-somlo@cmu.edu> In-Reply-To: <1446586842-21793-1-git-send-email-somlo@cmu.edu> References: <1446586842-21793-1-git-send-email-somlo@cmu.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v4 5/6] fw_cfg: add generic non-DMA read method List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, jordan.l.justen@intel.com, kraxel@redhat.com, pbonzini@redhat.com, markmb@redhat.com, lersek@redhat.com Introduce fw_cfg_data_read(), a generic read method which works on all access widths (1 through 8 bytes, inclusive), and can be used during both IOPort and MMIO read accesses. To maintain legibility, only fw_cfg_data_mem_read() (the MMIO data read method) is replaced by this patch. The new method essentially unwinds the fw_cfg_data_mem_read() + fw_cfg_read() combo, but without unnecessarily repeating all the validity checks performed by the latter on each byte being read. This patch also modifies the trace_fw_cfg_read prototype to accept a 64-bit value argument, allowing it to work properly with the new read method, but also remain backward compatible with existing call sites. Cc: Laszlo Ersek Cc: Gerd Hoffmann Cc: Marc Mar=C3=AD Signed-off-by: Gabriel Somlo --- hw/nvram/fw_cfg.c | 44 ++++++++++++++++++++++++++++++-------------- trace-events | 2 +- 2 files changed, 31 insertions(+), 15 deletions(-) diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 046fa74..9e01b46 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -274,6 +274,35 @@ static int fw_cfg_select(FWCfgState *s, uint16_t key= ) return ret; } =20 +static uint64_t fw_cfg_data_read(void *opaque, hwaddr addr, unsigned siz= e) +{ + FWCfgState *s =3D opaque; + int arch =3D !!(s->cur_entry & FW_CFG_ARCH_LOCAL); + FWCfgEntry *e =3D (s->cur_entry =3D=3D FW_CFG_INVALID) ? NULL : + &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK]; + uint64_t value =3D 0; + + assert(size <=3D sizeof(value)); + if (s->cur_entry !=3D FW_CFG_INVALID && e->data) { + /* The least significant 'size' bytes of the return value are + * expected to contain a string preserving portion of the item + * data, padded with zeros to the right in case we run out early. + */ + while (size && s->cur_offset < e->len) { + value =3D (value << 8) | e->data[s->cur_offset++]; + size--; + } + /* If size is still not zero, we *did* run out early, so continu= e + * left-shifting, to add the appropriate number of padding zeros + * on the right. + */ + value <<=3D 8 * size; + } + + trace_fw_cfg_read(s, value); + return value; +} + static uint8_t fw_cfg_read(FWCfgState *s) { int arch =3D !!(s->cur_entry & FW_CFG_ARCH_LOCAL); @@ -291,19 +320,6 @@ static uint8_t fw_cfg_read(FWCfgState *s) return ret; } =20 -static uint64_t fw_cfg_data_mem_read(void *opaque, hwaddr addr, - unsigned size) -{ - FWCfgState *s =3D opaque; - uint64_t value =3D 0; - unsigned i; - - for (i =3D 0; i < size; ++i) { - value =3D (value << 8) | fw_cfg_read(s); - } - return value; -} - static void fw_cfg_data_mem_write(void *opaque, hwaddr addr, uint64_t value, unsigned size) { @@ -485,7 +501,7 @@ static const MemoryRegionOps fw_cfg_ctl_mem_ops =3D { }; =20 static const MemoryRegionOps fw_cfg_data_mem_ops =3D { - .read =3D fw_cfg_data_mem_read, + .read =3D fw_cfg_data_read, .write =3D fw_cfg_data_mem_write, .endianness =3D DEVICE_BIG_ENDIAN, .valid =3D { diff --git a/trace-events b/trace-events index 72136b9..5073040 100644 --- a/trace-events +++ b/trace-events @@ -196,7 +196,7 @@ ecc_diag_mem_readb(uint64_t addr, uint32_t ret) "Read= diagnostic %"PRId64"=3D %02x =20 # hw/nvram/fw_cfg.c fw_cfg_select(void *s, uint16_t key, int ret) "%p key %d =3D %d" -fw_cfg_read(void *s, uint8_t ret) "%p =3D %d" +fw_cfg_read(void *s, uint64_t ret) "%p =3D %"PRIx64 fw_cfg_add_file(void *s, int index, char *name, size_t len) "%p #%d: %s = (%zd bytes)" =20 # hw/block/hd-geometry.c --=20 2.4.3