| Message ID | 1320041218-30487-4-git-send-email-david@gibson.dropbear.id.au |
|---|---|
| State | New |
| Headers | show |
On Mon, Oct 31, 2011 at 05:06:47PM +1100, David Gibson wrote: > This patch adds functions to pci.[ch] to perform PCI DMA operations. > At present, these are just stubs which perform directly cpu physical > memory accesses. Stubs are included which are analogous to > cpu_physical_memory_{read,write}(), the stX_phys() and ldX_phys() > functions and cpu_physical_memory_{map,unmap}(). > > In addition, a wrapper around qemu_sglist_init() is provided, which > also takes a PCIDevice *. It's assumed that _init() is the only > sglist function which will need wrapping, the idea being that once we > have IOMMU support whatever IOMMU context handle the wrapper derives > from the PCI device will be stored within the sglist structure for > later use. > > Using these stubs, however, distinguishes PCI device DMA transactions from > other accesses to physical memory, which will allow PCI IOMMU support to > be added in one place, rather than updating every PCI driver at that time. > > That is, it allows us to update individual PCI drivers to support an IOMMU > without having yet determined the details of how the IOMMU emulation will > operate. This will let us remove the most bitrot-sensitive part of an > IOMMU patch in advance. > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > hw/pci.h | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 67 insertions(+), 0 deletions(-) > > diff --git a/hw/pci.h b/hw/pci.h > index 86a81c8..c449a90 100644 > --- a/hw/pci.h > +++ b/hw/pci.h > @@ -6,6 +6,7 @@ > > #include "qdev.h" > #include "memory.h" > +#include "dma.h" > > /* PCI includes legacy ISA access. */ > #include "isa.h" > @@ -487,4 +488,70 @@ static inline uint32_t pci_config_size(const PCIDevice *d) > return pci_is_express(d) ? PCIE_CONFIG_SPACE_SIZE : PCI_CONFIG_SPACE_SIZE; > } > > +/* DMA access functions */ > +static inline int pci_dma_rw(PCIDevice *dev, dma_addr_t addr, > + void *buf, dma_addr_t len, DMADirection dir) > +{ > + cpu_physical_memory_rw(addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE); > + return 0; > +} > + > +static inline int pci_dma_read(PCIDevice *dev, dma_addr_t addr, > + void *buf, dma_addr_t len) > +{ > + return pci_dma_rw(dev, addr, buf, len, DMA_DIRECTION_TO_DEVICE); > +} > + > +static inline int pci_dma_write(PCIDevice *dev, dma_addr_t addr, > + const void *buf, dma_addr_t len) > +{ > + return pci_dma_rw(dev, addr, (void *) buf, len, DMA_DIRECTION_FROM_DEVICE); > +} > + > +#define PCI_DMA_DEFINE_LDST(_l, _s, _bits) \ > + static inline uint##_bits##_t ld##_l##_pci_dma(PCIDevice *dev, \ > + dma_addr_t addr) \ > + { \ > + return ld##_l##_phys(addr); \ > + } \ > + static inline void st##_s##_pci_dma(PCIDevice *dev, \ > + dma_addr_t addr, uint##_bits##_t val) \ > + { \ > + st##_s##_phys(addr, val); \ > + } > + I'd much rather name APIs pci_dma_XXX. why use a suffix and not a prefix? > +PCI_DMA_DEFINE_LDST(ub, b, 8); > +PCI_DMA_DEFINE_LDST(uw_le, w_le, 16) > +PCI_DMA_DEFINE_LDST(l_le, l_le, 32); > +PCI_DMA_DEFINE_LDST(q_le, q_le, 64); > +PCI_DMA_DEFINE_LDST(uw_be, w_be, 16) > +PCI_DMA_DEFINE_LDST(l_be, l_be, 32); > +PCI_DMA_DEFINE_LDST(q_be, q_be, 64); > + > +#undef PCI_DMA_DEFINE_LDST > + > +static inline void *pci_dma_map(PCIDevice *dev, dma_addr_t addr, > + dma_addr_t *plen, DMADirection dir) > +{ > + target_phys_addr_t len = *plen; > + void *buf; > + > + buf = cpu_physical_memory_map(addr, &len, dir == DMA_DIRECTION_FROM_DEVICE); > + *plen = len; > + return buf; > +} > + > +static inline void pci_dma_unmap(PCIDevice *dev, void *buffer, dma_addr_t len, > + DMADirection dir, dma_addr_t access_len) > +{ > + cpu_physical_memory_unmap(buffer, len, dir == DMA_DIRECTION_FROM_DEVICE, > + access_len); > +} > + > +static inline void pci_dma_sglist_init(QEMUSGList *qsg, PCIDevice *dev, > + int alloc_hint) > +{ > + qemu_sglist_init(qsg, alloc_hint); > +} > + > #endif > -- > 1.7.7
On Wed, Nov 02, 2011 at 09:17:37AM +0200, Michael S. Tsirkin wrote: > On Mon, Oct 31, 2011 at 05:06:47PM +1100, David Gibson wrote: > > This patch adds functions to pci.[ch] to perform PCI DMA operations. > > At present, these are just stubs which perform directly cpu physical > > memory accesses. Stubs are included which are analogous to > > cpu_physical_memory_{read,write}(), the stX_phys() and ldX_phys() > > functions and cpu_physical_memory_{map,unmap}(). > > > > In addition, a wrapper around qemu_sglist_init() is provided, which > > also takes a PCIDevice *. It's assumed that _init() is the only > > sglist function which will need wrapping, the idea being that once we > > have IOMMU support whatever IOMMU context handle the wrapper derives > > from the PCI device will be stored within the sglist structure for > > later use. > > > > Using these stubs, however, distinguishes PCI device DMA transactions from > > other accesses to physical memory, which will allow PCI IOMMU support to > > be added in one place, rather than updating every PCI driver at that time. > > > > That is, it allows us to update individual PCI drivers to support an IOMMU > > without having yet determined the details of how the IOMMU emulation will > > operate. This will let us remove the most bitrot-sensitive part of an > > IOMMU patch in advance. > > > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > > --- > > hw/pci.h | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 files changed, 67 insertions(+), 0 deletions(-) > > > > diff --git a/hw/pci.h b/hw/pci.h > > index 86a81c8..c449a90 100644 > > --- a/hw/pci.h > > +++ b/hw/pci.h > > @@ -6,6 +6,7 @@ > > > > #include "qdev.h" > > #include "memory.h" > > +#include "dma.h" > > > > /* PCI includes legacy ISA access. */ > > #include "isa.h" > > @@ -487,4 +488,70 @@ static inline uint32_t pci_config_size(const PCIDevice *d) > > return pci_is_express(d) ? PCIE_CONFIG_SPACE_SIZE : PCI_CONFIG_SPACE_SIZE; > > } > > > > +/* DMA access functions */ > > +static inline int pci_dma_rw(PCIDevice *dev, dma_addr_t addr, > > + void *buf, dma_addr_t len, DMADirection dir) > > +{ > > + cpu_physical_memory_rw(addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE); > > + return 0; > > +} > > + > > +static inline int pci_dma_read(PCIDevice *dev, dma_addr_t addr, > > + void *buf, dma_addr_t len) > > +{ > > + return pci_dma_rw(dev, addr, buf, len, DMA_DIRECTION_TO_DEVICE); > > +} > > + > > +static inline int pci_dma_write(PCIDevice *dev, dma_addr_t addr, > > + const void *buf, dma_addr_t len) > > +{ > > + return pci_dma_rw(dev, addr, (void *) buf, len, DMA_DIRECTION_FROM_DEVICE); > > +} > > + > > +#define PCI_DMA_DEFINE_LDST(_l, _s, _bits) \ > > + static inline uint##_bits##_t ld##_l##_pci_dma(PCIDevice *dev, \ > > + dma_addr_t addr) \ > > + { \ > > + return ld##_l##_phys(addr); \ > > + } \ > > + static inline void st##_s##_pci_dma(PCIDevice *dev, \ > > + dma_addr_t addr, uint##_bits##_t val) \ > > + { \ > > + st##_s##_phys(addr, val); \ > > + } > > + > > I'd much rather name APIs pci_dma_XXX. > why use a suffix and not a prefix? Because the analogous stX_phys/ldX_phys functions do.
diff --git a/hw/pci.h b/hw/pci.h index 86a81c8..c449a90 100644 --- a/hw/pci.h +++ b/hw/pci.h @@ -6,6 +6,7 @@ #include "qdev.h" #include "memory.h" +#include "dma.h" /* PCI includes legacy ISA access. */ #include "isa.h" @@ -487,4 +488,70 @@ static inline uint32_t pci_config_size(const PCIDevice *d) return pci_is_express(d) ? PCIE_CONFIG_SPACE_SIZE : PCI_CONFIG_SPACE_SIZE; } +/* DMA access functions */ +static inline int pci_dma_rw(PCIDevice *dev, dma_addr_t addr, + void *buf, dma_addr_t len, DMADirection dir) +{ + cpu_physical_memory_rw(addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE); + return 0; +} + +static inline int pci_dma_read(PCIDevice *dev, dma_addr_t addr, + void *buf, dma_addr_t len) +{ + return pci_dma_rw(dev, addr, buf, len, DMA_DIRECTION_TO_DEVICE); +} + +static inline int pci_dma_write(PCIDevice *dev, dma_addr_t addr, + const void *buf, dma_addr_t len) +{ + return pci_dma_rw(dev, addr, (void *) buf, len, DMA_DIRECTION_FROM_DEVICE); +} + +#define PCI_DMA_DEFINE_LDST(_l, _s, _bits) \ + static inline uint##_bits##_t ld##_l##_pci_dma(PCIDevice *dev, \ + dma_addr_t addr) \ + { \ + return ld##_l##_phys(addr); \ + } \ + static inline void st##_s##_pci_dma(PCIDevice *dev, \ + dma_addr_t addr, uint##_bits##_t val) \ + { \ + st##_s##_phys(addr, val); \ + } + +PCI_DMA_DEFINE_LDST(ub, b, 8); +PCI_DMA_DEFINE_LDST(uw_le, w_le, 16) +PCI_DMA_DEFINE_LDST(l_le, l_le, 32); +PCI_DMA_DEFINE_LDST(q_le, q_le, 64); +PCI_DMA_DEFINE_LDST(uw_be, w_be, 16) +PCI_DMA_DEFINE_LDST(l_be, l_be, 32); +PCI_DMA_DEFINE_LDST(q_be, q_be, 64); + +#undef PCI_DMA_DEFINE_LDST + +static inline void *pci_dma_map(PCIDevice *dev, dma_addr_t addr, + dma_addr_t *plen, DMADirection dir) +{ + target_phys_addr_t len = *plen; + void *buf; + + buf = cpu_physical_memory_map(addr, &len, dir == DMA_DIRECTION_FROM_DEVICE); + *plen = len; + return buf; +} + +static inline void pci_dma_unmap(PCIDevice *dev, void *buffer, dma_addr_t len, + DMADirection dir, dma_addr_t access_len) +{ + cpu_physical_memory_unmap(buffer, len, dir == DMA_DIRECTION_FROM_DEVICE, + access_len); +} + +static inline void pci_dma_sglist_init(QEMUSGList *qsg, PCIDevice *dev, + int alloc_hint) +{ + qemu_sglist_init(qsg, alloc_hint); +} + #endif
This patch adds functions to pci.[ch] to perform PCI DMA operations. At present, these are just stubs which perform directly cpu physical memory accesses. Stubs are included which are analogous to cpu_physical_memory_{read,write}(), the stX_phys() and ldX_phys() functions and cpu_physical_memory_{map,unmap}(). In addition, a wrapper around qemu_sglist_init() is provided, which also takes a PCIDevice *. It's assumed that _init() is the only sglist function which will need wrapping, the idea being that once we have IOMMU support whatever IOMMU context handle the wrapper derives from the PCI device will be stored within the sglist structure for later use. Using these stubs, however, distinguishes PCI device DMA transactions from other accesses to physical memory, which will allow PCI IOMMU support to be added in one place, rather than updating every PCI driver at that time. That is, it allows us to update individual PCI drivers to support an IOMMU without having yet determined the details of how the IOMMU emulation will operate. This will let us remove the most bitrot-sensitive part of an IOMMU patch in advance. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> --- hw/pci.h | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 67 insertions(+), 0 deletions(-)