From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45532) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UyFxG-0006qM-Oi for qemu-devel@nongnu.org; Sun, 14 Jul 2013 02:38:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UyFxF-0006xd-L2 for qemu-devel@nongnu.org; Sun, 14 Jul 2013 02:38:46 -0400 Received: from mail-ee0-x22a.google.com ([2a00:1450:4013:c00::22a]:40829) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UyFxF-0006xY-BA for qemu-devel@nongnu.org; Sun, 14 Jul 2013 02:38:45 -0400 Received: by mail-ee0-f42.google.com with SMTP id c4so6903169eek.15 for ; Sat, 13 Jul 2013 23:38:44 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <51E2476C.20207@redhat.com> Date: Sun, 14 Jul 2013 08:38:36 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1373331672-19852-1-git-send-email-rth@twiddle.net> <1373331672-19852-4-git-send-email-rth@twiddle.net> In-Reply-To: <1373331672-19852-4-git-send-email-rth@twiddle.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/4] exec: Support 64-bit operations in address_space_rw List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org Il 09/07/2013 03:01, Richard Henderson ha scritto: > Honor the implementation maximum access size, and at least check > the minimum access size. > > Signed-off-by: Richard Henderson > --- > exec.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 56 insertions(+), 12 deletions(-) > > diff --git a/exec.c b/exec.c > index 03fdf7e..5da22dc 100644 > --- a/exec.c > +++ b/exec.c > @@ -1902,15 +1902,37 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write) > return false; > } > > -static inline int memory_access_size(MemoryRegion *mr, int l, hwaddr addr) > +static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr) > { > - if (l >= 4 && (((addr & 3) == 0 || mr->ops->impl.unaligned))) { > - return 4; > + unsigned access_size_min = mr->ops->impl.min_access_size; > + unsigned access_size_max = mr->ops->impl.max_access_size; > + > + /* Regions are assumed to support 1-4 byte accesses unless > + otherwise specified. */ > + if (access_size_min == 0) { > + access_size_min = 1; > + } > + if (access_size_max == 0) { > + access_size_max = 4; > + } > + > + /* Bound the maximum access by the alignment of the address. */ > + if (!mr->ops->impl.unaligned) { > + unsigned align_size_max = addr & -addr; > + if (align_size_max != 0 && align_size_max < access_size_max) { > + access_size_max = align_size_max; > + } > } > - if (l >= 2 && (((addr & 1) == 0) || mr->ops->impl.unaligned)) { > - return 2; > + > + /* Don't attempt accesses larger than the maximum. */ > + if (l > access_size_max) { > + l = access_size_max; > } > - return 1; > + /* ??? The users of this function are wrong, not supporting minimums larger > + than the remaining length. C.f. memory.c:access_with_adjusted_size. */ > + assert(l >= access_size_min); > + > + return l; > } > > bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, > @@ -1932,18 +1954,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, > l = memory_access_size(mr, l, addr1); > /* XXX: could force cpu_single_env to NULL to avoid > potential bugs */ > - if (l == 4) { > + switch (l) { > + case 8: > + /* 64 bit write access */ > + val = ldq_p(buf); > + error |= io_mem_write(mr, addr1, val, 8); > + break; > + case 4: > /* 32 bit write access */ > val = ldl_p(buf); > error |= io_mem_write(mr, addr1, val, 4); > - } else if (l == 2) { > + break; > + case 2: > /* 16 bit write access */ > val = lduw_p(buf); > error |= io_mem_write(mr, addr1, val, 2); > - } else { > + break; > + case 1: > /* 8 bit write access */ > val = ldub_p(buf); > error |= io_mem_write(mr, addr1, val, 1); > + break; > + default: > + abort(); > } > } else { > addr1 += memory_region_get_ram_addr(mr); > @@ -1956,18 +1989,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, > if (!memory_access_is_direct(mr, is_write)) { > /* I/O case */ > l = memory_access_size(mr, l, addr1); > - if (l == 4) { > + switch (l) { > + case 8: > + /* 64 bit read access */ > + error |= io_mem_read(mr, addr1, &val, 8); > + stq_p(buf, val); > + break; > + case 4: > /* 32 bit read access */ > error |= io_mem_read(mr, addr1, &val, 4); > stl_p(buf, val); > - } else if (l == 2) { > + break; > + case 2: > /* 16 bit read access */ > error |= io_mem_read(mr, addr1, &val, 2); > stw_p(buf, val); > - } else { > + break; > + case 1: > /* 8 bit read access */ > error |= io_mem_read(mr, addr1, &val, 1); > stb_p(buf, val); > + break; > + default: > + abort(); > } > } else { > /* RAM case */ > Reviewed-by: Paolo Bonzini