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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC PATCH 03/24] ARM: GICv3 ITS: allocate device and collection table
On Wed, 28 Sep 2016, Andre Przywara wrote:
> Each ITS maps a pair of a DeviceID (usually the PCI b/d/f triplet) and
> an EventID (the MSI payload or interrupt ID) to a pair of LPI number
> and collection ID, which points to the target CPU.
> This mapping is stored in the device and collection tables, which software
> has to provide for the ITS to use.
> Allocate the required memory and hand it the ITS.
> We limit the number of devices to cover 4 PCI busses for now.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> xen/arch/arm/gic-its.c | 114
> ++++++++++++++++++++++++++++++++++++++++++
> xen/arch/arm/gic-v3.c | 5 ++
> xen/include/asm-arm/gic-its.h | 49 +++++++++++++++++-
> 3 files changed, 167 insertions(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/gic-its.c b/xen/arch/arm/gic-its.c
> index b52dff3..40238a2 100644
> --- a/xen/arch/arm/gic-its.c
> +++ b/xen/arch/arm/gic-its.c
> @@ -21,6 +21,7 @@
> #include <xen/device_tree.h>
> #include <xen/libfdt/libfdt.h>
> #include <asm/p2m.h>
> +#include <asm/io.h>
> #include <asm/gic.h>
> #include <asm/gic_v3_defs.h>
> #include <asm/gic-its.h>
> @@ -38,6 +39,119 @@ static DEFINE_PER_CPU(void *, pending_table);
> min_t(unsigned int, lpi_data.host_lpi_bits, CONFIG_HOST_LPI_BITS)
> #define MAX_HOST_LPIS (BIT(MAX_HOST_LPI_BITS) - 8192)
>
> +#define BASER_ATTR_MASK \
> + ((0x3UL << GITS_BASER_SHAREABILITY_SHIFT) | \
> + (0x7UL << GITS_BASER_OUTER_CACHEABILITY_SHIFT) | \
> + (0x7UL << GITS_BASER_INNER_CACHEABILITY_SHIFT))
> +#define BASER_RO_MASK (GENMASK(52, 48) | GENMASK(58, 56))
> +
> +static uint64_t encode_phys_addr(paddr_t addr, int page_bits)
> +{
> + uint64_t ret;
> +
> + if ( page_bits < 16)
> + return (uint64_t)addr & GENMASK(47, page_bits);
> +
> + ret = addr & GENMASK(47, 16);
> + return ret | (addr & GENMASK(51, 48)) >> (48 - 12);
> +}
> +
> +static int gicv3_map_baser(void __iomem *basereg, uint64_t regc, int
> nr_items)
Shouldn't this be called its_map_baser?
> +{
> + uint64_t attr;
> + int entry_size = (regc >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0x1f;
The spec says "This field is read-only and specifies the number of
bytes per entry, minus one." Do we need to increment it by 1?
> + int pagesz;
> + int order;
> + void *buffer = NULL;
> +
> + attr = GIC_BASER_InnerShareable << GITS_BASER_SHAREABILITY_SHIFT;
> + attr |= GIC_BASER_CACHE_SameAsInner <<
> GITS_BASER_OUTER_CACHEABILITY_SHIFT;
> + attr |= GIC_BASER_CACHE_RaWaWb << GITS_BASER_INNER_CACHEABILITY_SHIFT;
> +
> + /*
> + * Loop over the page sizes (4K, 16K, 64K) to find out what the host
> + * supports.
> + */
Is this really the best way to do it? Can't we assume ITS supports 4K,
given that Xen requires 4K pages at the moment? Is it actually possible
to find hardware that supports 4K but with an ITS that only support 64K
or 16K pages? It seems insane to me. Otherwise can't we probe the page
size somehow?
> + for (pagesz = 0; pagesz < 3; pagesz++)
> + {
> + uint64_t reg;
> + int nr_bytes;
> +
> + nr_bytes = ROUNDUP(nr_items * entry_size, BIT(pagesz * 2 + 12));
> + order = get_order_from_bytes(nr_bytes);
> +
> + if ( !buffer )
> + buffer = alloc_xenheap_pages(order, 0);
> + if ( !buffer )
> + return -ENOMEM;
> +
> + reg = attr;
> + reg |= (pagesz << GITS_BASER_PAGE_SIZE_SHIFT);
> + reg |= nr_bytes >> (pagesz * 2 + 12);
> + reg |= regc & BASER_RO_MASK;
> + reg |= GITS_BASER_VALID;
> + reg |= encode_phys_addr(virt_to_maddr(buffer), pagesz * 2 + 12);
> +
> + writeq_relaxed(reg, basereg);
> + regc = readl_relaxed(basereg);
> +
> + /* The host didn't like our attributes, just use what it returned. */
> + if ( (regc & BASER_ATTR_MASK) != attr )
> + attr = regc & BASER_ATTR_MASK;
> +
> + /* If the host accepted our page size, we are done. */
> + if ( (reg & (3UL << GITS_BASER_PAGE_SIZE_SHIFT)) == pagesz )
> + return 0;
> +
> + /* Check whether our buffer is aligned to the next page size
> already. */
> + if ( !(virt_to_maddr(buffer) & (BIT(pagesz * 2 + 12 + 2) - 1)) )
> + {
> + free_xenheap_pages(buffer, order);
> + buffer = NULL;
> + }
> + }
> +
> + if ( buffer )
> + free_xenheap_pages(buffer, order);
> +
> + return -EINVAL;
> +}
> +
> +int gicv3_its_init(struct host_its *hw_its)
> +{
> + uint64_t reg;
> + int i;
> +
> + hw_its->its_base = ioremap_nocache(hw_its->addr, hw_its->size);
> + if ( !hw_its->its_base )
> + return -ENOMEM;
> +
> + for (i = 0; i < 8; i++)
Code style. Unfortunately we don't have a script to check, but please
refer to CODING_STYLE. I'd prefer if every number was #define'ed,
including `8' (something like GITS_BASER_MAX).
> + {
> + void __iomem *basereg = hw_its->its_base + GITS_BASER0 + i * 8;
> + int type;
> +
> + reg = readq_relaxed(basereg);
> + type = (reg >> 56) & 0x7;
Please #define 56 and 0x7
> + switch ( type )
> + {
> + case GITS_BASER_TYPE_NONE:
> + continue;
> + case GITS_BASER_TYPE_DEVICE:
> + /* TODO: find some better way of limiting the number of devices
> */
> + gicv3_map_baser(basereg, reg, 1024);
An hardcoded max value might be OK, but please #define it.
> + break;
> + case GITS_BASER_TYPE_COLLECTION:
> + gicv3_map_baser(basereg, reg, NR_CPUS);
> + break;
> + default:
> + continue;
> + }
> + }
> +
> + return 0;
> +}
> +
> uint64_t gicv3_lpi_allocate_pendtable(void)
> {
> uint64_t reg, attr;
> diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
> index 2534aa5..5cf4618 100644
> --- a/xen/arch/arm/gic-v3.c
> +++ b/xen/arch/arm/gic-v3.c
> @@ -29,6 +29,7 @@
> #include <xen/irq.h>
> #include <xen/iocap.h>
> #include <xen/sched.h>
> +#include <xen/err.h>
> #include <xen/errno.h>
> #include <xen/delay.h>
> #include <xen/device_tree.h>
> @@ -1548,6 +1549,7 @@ static int __init gicv3_init(void)
> {
> int res, i;
> uint32_t reg;
> + struct host_its *hw_its;
>
> if ( !cpu_has_gicv3 )
> {
> @@ -1603,6 +1605,9 @@ static int __init gicv3_init(void)
> res = gicv3_cpu_init();
> gicv3_hyp_init();
>
> + list_for_each_entry(hw_its, &host_its_list, entry)
> + gicv3_its_init(hw_its);
> +
> spin_unlock(&gicv3.lock);
>
> return res;
> diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
> index 48c6c78..589b889 100644
> --- a/xen/include/asm-arm/gic-its.h
> +++ b/xen/include/asm-arm/gic-its.h
> @@ -18,6 +18,47 @@
> #ifndef __ASM_ARM_ITS_H__
> #define __ASM_ARM_ITS_H__
>
> +#define LPI_OFFSET 8192
> +
> +#define GITS_CTLR (0x000)
> +#define GITS_IIDR (0x004)
> +#define GITS_TYPER (0x008)
> +#define GITS_CBASER (0x080)
> +#define GITS_CWRITER (0x088)
> +#define GITS_CREADR (0x090)
> +#define GITS_BASER0 (0x100)
> +#define GITS_BASER1 (0x108)
> +#define GITS_BASER2 (0x110)
> +#define GITS_BASER3 (0x118)
> +#define GITS_BASER4 (0x120)
> +#define GITS_BASER5 (0x128)
> +#define GITS_BASER6 (0x130)
> +#define GITS_BASER7 (0x138)
> +
> +/* Register bits */
> +#define GITS_CTLR_ENABLE 0x1
> +#define GITS_IIDR_VALUE 0x34c
> +
> +#define GITS_BASER_VALID BIT(63)
> +#define GITS_BASER_INDIRECT BIT(62)
> +#define GITS_BASER_INNER_CACHEABILITY_SHIFT 59
> +#define GITS_BASER_TYPE_SHIFT 56
> +#define GITS_BASER_OUTER_CACHEABILITY_SHIFT 53
> +#define GITS_BASER_TYPE_NONE 0UL
> +#define GITS_BASER_TYPE_DEVICE 1UL
> +#define GITS_BASER_TYPE_VCPU 2UL
> +#define GITS_BASER_TYPE_CPU 3UL
> +#define GITS_BASER_TYPE_COLLECTION 4UL
> +#define GITS_BASER_TYPE_RESERVED5 5UL
> +#define GITS_BASER_TYPE_RESERVED6 6UL
> +#define GITS_BASER_TYPE_RESERVED7 7UL
> +#define GITS_BASER_ENTRY_SIZE_SHIFT 48
> +#define GITS_BASER_SHAREABILITY_SHIFT 10
> +#define GITS_BASER_PAGE_SIZE_SHIFT 8
> +#define GITS_BASER_RO_MASK ((7UL << GITS_BASER_TYPE_SHIFT) | \
> + (31UL <<
> GITS_BASER_ENTRY_SIZE_SHIFT) |\
> + GITS_BASER_INDIRECT)
> +
> #ifndef __ASSEMBLY__
> #include <xen/device_tree.h>
>
> @@ -27,6 +68,7 @@ struct host_its {
> const struct dt_device_node *dt_node;
> paddr_t addr;
> paddr_t size;
> + void __iomem *its_base;
> };
>
> extern struct list_head host_its_list;
> @@ -42,8 +84,9 @@ void gicv3_its_dt_init(const struct dt_device_node *node);
> uint64_t gicv3_lpi_get_proptable(void);
> uint64_t gicv3_lpi_allocate_pendtable(void);
>
> -/* Initialize the host structures for LPIs. */
> +/* Initialize the host structures for LPIs and the host ITSes. */
> int gicv3_lpi_init_host_lpis(int nr_lpis);
> +int gicv3_its_init(struct host_its *hw_its);
>
> #else
>
> @@ -62,6 +105,10 @@ static inline int gicv3_lpi_init_host_lpis(int nr_lpis)
> {
> return 0;
> }
> +static inline int gicv3_its_init(struct host_its *hw_its)
> +{
> + return 0;
> +}
> #endif /* CONFIG_HAS_ITS */
>
> #endif /* __ASSEMBLY__ */
> --
> 2.9.0
>
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