From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Mv7ES-0002uy-Ji for qemu-devel@nongnu.org; Tue, 06 Oct 2009 06:25:24 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Mv7EN-0002pl-7p for qemu-devel@nongnu.org; Tue, 06 Oct 2009 06:25:23 -0400 Received: from [199.232.76.173] (port=37883 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Mv7EN-0002pa-12 for qemu-devel@nongnu.org; Tue, 06 Oct 2009 06:25:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23535) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Mv7EM-00071y-FF for qemu-devel@nongnu.org; Tue, 06 Oct 2009 06:25:18 -0400 Date: Tue, 6 Oct 2009 12:23:13 +0200 From: "Michael S. Tsirkin" Message-ID: <20091006102313.GB8916@redhat.com> References: <1254737223-16129-1-git-send-email-yamahata@valinux.co.jp> <1254737223-16129-15-git-send-email-yamahata@valinux.co.jp> <20091005124533.GD30799@redhat.com> <20091006095005.GD32367%yamahata@valinux.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091006095005.GD32367%yamahata@valinux.co.jp> Subject: [Qemu-devel] Re: [PATCH 14/23] pci: factor out the logic to get pci device from address. List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Isaku Yamahata Cc: qemu-devel@nongnu.org On Tue, Oct 06, 2009 at 06:50:05PM +0900, Isaku Yamahata wrote: > On Mon, Oct 05, 2009 at 02:45:33PM +0200, Michael S. Tsirkin wrote: > > On Mon, Oct 05, 2009 at 07:06:54PM +0900, Isaku Yamahata wrote: > > > factor out conversion logic from io port address into bus+dev+func > > > with bit shift operation and conversion bus+dev+func into pci device. > > > They will be used later by pcie support. > > > This patch also eliminates the logic duplication. > > > > Please split removing logic duplication into separate patch. > > It might be applicable already, while express stuff needs more work IMO. > > > > > Signed-off-by: Isaku Yamahata > > > --- > > > hw/pci.c | 83 ++++++++++++++++++++++++++++++++++--------------------------- > > > 1 files changed, 46 insertions(+), 37 deletions(-) > > > > > > diff --git a/hw/pci.c b/hw/pci.c > > > index 6ddd256..5f808ff 100644 > > > --- a/hw/pci.c > > > +++ b/hw/pci.c > > > @@ -629,44 +629,25 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l) > > > pci_update_mappings(d); > > > } > > > > > > -void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len) > > > +static void pci_data_write_common(PCIDevice *pci_dev, > > > + uint32_t config_addr, uint32_t val, int len) > > > > So as I said in the previous comment, pci express should just be able to > > use pci code directly, instead of reusing this low-level stuff. > > All you need to do is range-check address and ignore extended registers. > > Maybe my patch description isn't good enough, > I'm afraid that you misunderstood the patch purpose. > > PCI configuration and PCI express MMCONFIG uses different address scheme > as follows. > This patch purpose is to separate out its address parsing logic > from pci config space update logic. > > PCI: > 0- 7 bit: offset in the configuration space (256bytes) > 7-15 bit: devfn > 16-14 bit: bus > > PCI express: > 0-11 bit: offset in the configuration space (4KBytes) > 12-19 bit: devfn > 20-28 bit: bus The comment is basically that there's no common code: you don't need len checks that you added for mmconfig (they are there just for documentation purposes), and so all pci_data_write does is address parsing. So just call pci_dev->config_write for both mmconfig and config. > > > { > > > - PCIBus *s = opaque; > > > - PCIDevice *pci_dev; > > > - int config_addr, bus_num; > > > - > > > -#if 0 > > > - PCI_DPRINTF("pci_data_write: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n", > > > - addr, val, len); > > > -#endif > > > - bus_num = (addr >> 16) & 0xff; > > > - s = pci_find_bus(s, bus_num); > > > - if (!s) > > > - return; > > > - pci_dev = s->devices[(addr >> 8) & 0xff]; > > > + assert(len == 1 || len == 2 || len == 4); > > > if (!pci_dev) > > > return; > > > - config_addr = addr & 0xff; > > > - PCI_DPRINTF("pci_config_write: %s: " > > > - "addr=%02x val=%08"PRI32x" len=%d\n", > > > - pci_dev->name, config_addr, val, len); > > > + > > > + PCI_DPRINTF("%s: %s: addr=%02"PRIx32" val=%08"PRI32x" len=%d\n", > > > + __func__, pci_dev->name, config_addr, val, len); > > > pci_dev->config_write(pci_dev, config_addr, val, len); > > > } > > > > > > -uint32_t pci_data_read(void *opaque, uint32_t addr, int len) > > > +static uint32_t pci_data_read_common(PCIDevice *pci_dev, > > > + uint32_t config_addr, int len) > > > { > > > - PCIBus *s = opaque; > > > - PCIDevice *pci_dev; > > > - int config_addr, bus_num; > > > uint32_t val; > > > > > > - bus_num = (addr >> 16) & 0xff; > > > - s = pci_find_bus(s, bus_num); > > > - if (!s) > > > - goto fail; > > > - pci_dev = s->devices[(addr >> 8) & 0xff]; > > > + assert(len == 1 || len == 2 || len == 4); > > > if (!pci_dev) { > > > - fail: > > > switch(len) { > > > case 1: > > > val = 0xff; > > > @@ -679,21 +660,49 @@ uint32_t pci_data_read(void *opaque, uint32_t addr, int len) > > > val = 0xffffffff; > > > break; > > > } > > > - goto the_end; > > > + } else { > > > + val = pci_dev->config_read(pci_dev, config_addr, len); > > > + PCI_DPRINTF("%s: %s: addr=%02"PRIx32" val=%08"PRIx32" len=%d\n", > > > + __func__, pci_dev->name, config_addr, val, len); > > > } > > > - config_addr = addr & 0xff; > > > - val = pci_dev->config_read(pci_dev, config_addr, len); > > > - PCI_DPRINTF("pci_config_read: %s: " > > > - "addr=%02x val=%08"PRIx32" len=%d\n", > > > - pci_dev->name, config_addr, val, len); > > > - the_end: > > > + > > > #if 0 > > > - PCI_DPRINTF("pci_data_read: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n", > > > - addr, val, len); > > > + PCI_DPRINTF("%s: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n", > > > + __func__, addr, val, len); > > > #endif > > > > move to real pci_data_read? > > > > > return val; > > > } > > > > > > +static inline PCIDevice *pci_addr_to_dev(PCIBus *bus, uint32_t addr) > > > +{ > > > + uint8_t bus_num = (addr >> 16) & 0xff; > > > + uint8_t devfn = (addr >> 8) & 0xff; > > > + return pci_find_device(bus, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn)); > > > +} > > > + > > > +static inline uint32_t pci_addr_to_config(uint32_t addr) > > > +{ > > > + return addr & 0xff; > > > +} > > > + > > > +void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len) > > > +{ > > > + PCIBus *s = opaque; > > > +#if 0 > > > + PCI_DPRINTF("pci_data_write: addr=%08"PRIx32" val=%08"PRIx32" len=%d\n", > > > + addr, val, len); > > > +#endif > > > + > > > + pci_data_write_common(pci_addr_to_dev(s, addr), pci_addr_to_config(addr), > > > + val, len); > > > > For pci express, there's extended register number in bits 11:8 > > so what we should do here IMO is check these bits and > > ignore if they are not 0. > > I don't understand what you suggest. > pci_data_{write, read}() are glue for ioio or mmio to > access pci configuration space. And 'addr' parameter is used > to specify configuration space access. > It includes not only the offset in configuration space, but also > devfn and bus. > Okay. I was misled by naming. What I am saying, here and elsewhere, is that a large part of pain is because of 256 byte/4K byte difference. Since in express you can hardware addresses > 256 to 0, I propose that we simply make mmconfig code do this: if (offset > 256) return 0; And then basically nothing needs to be changed in pci. > > > > +} > > > + > > > +uint32_t pci_data_read(void *opaque, uint32_t addr, int len) > > > +{ > > > + PCIBus *s = opaque; > > > > For pci express, there's extended register number in bits 11:8 > > so what we should do here IMO is check these bits and > > return 0 if not 0. > > > > > + return pci_data_read_common(pci_addr_to_dev(s, addr), > > > + pci_addr_to_config(addr), len); > > > +} > > > /***********************************************************/ > > > /* generic PCI irq support */ > > > > > > > -- > yamahata