Re: [patch 01/11] GRU Driver - hardware data structures

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 09 Jun 2008 16:10:29 -0500
steiner@sgi.com wrote:

> This patch contains the definitions of the hardware GRU data structures that are used
> by the driver to manage the GRU.
> 

oh goody, more code to review.

>
> ...
>
> +/* Convert resource counts to the number of AU */
> +#define GRU_DS_BYTES_TO_AU(n)	(((n) + GRU_DSR_AU_BYTES - 1) / \
> +				 GRU_DSR_AU_BYTES)
> +#define GRU_CB_COUNT_TO_AU(n)	(((n) + GRU_CBR_AU_SIZE - 1) / 	\
> +				 GRU_CBR_AU_SIZE)

These are open-coded ROUND_UP()s

> +/* UV limits */
> +#define GRU_CHIPLETS_PER_HUB	2
> +#define GRU_HUBS_PER_BLADE	1
> +#define GRU_CHIPLETS_PER_BLADE	(GRU_HUBS_PER_BLADE * GRU_CHIPLETS_PER_HUB)
> +
> +/* User GRU Gseg offsets */
> +#define GRU_CB_BASE		0
> +#define GRU_CB_LIMIT		(GRU_CB_BASE + GRU_HANDLE_STRIDE * GRU_NUM_CBE)
> +#define GRU_DS_BASE		0x20000
> +#define GRU_DS_LIMIT		(GRU_DS_BASE + GRU_NUM_DSR_BYTES)
> +
> +/* General addressing macros. b=grubase, c=ctxnum, i=cbnum, cl=cacheline#  */
> +#define GRU_GSEG(b, c)		((void *)((b) + GRU_GSEG0_BASE +	\
> +		GRU_GSEG_STRIDE * (c)))
> +#define GRU_GSEG_CB(b, c, i)	((void *)(GRU_GSEG((b), (c)) +		\
> +		GRU_CB_BASE + GRU_HANDLE_STRIDE * (i)))
> +#define GRU_GSEG_DS(b, c, cl)	((void *)(GRU_GSEG((b), (c)) +		\
> +		GRU_DS_BASE + GRU_CACHE_LINE_BYTES * (cl)))
> +#define GRU_TFM(b, c)		((struct gru_tlb_fault_map *)		\
> +		((unsigned long)(b) + GRU_TFM_BASE + (c) * GRU_HANDLE_STRIDE))
> +#define GRU_TGH(b, c)		((struct gru_tlb_global_handle *)	\
> +		((unsigned long)(b) + GRU_TGH_BASE + (c) * GRU_HANDLE_STRIDE))
> +#define GRU_CBE(b, n)		((struct gru_control_block_extended *)	\
> +		((unsigned long)(b) + GRU_CBE_BASE + (n) * GRU_HANDLE_STRIDE))
> +#define GRU_TFH(b, n)		((struct gru_tlb_fault_handle *)	\
> +		((unsigned long)(b) + GRU_TFH_BASE + (n) * GRU_HANDLE_STRIDE))
> +#define GRU_CCH(b, n)		((struct gru_context_configuration_handle *) \
> +		((unsigned long)(b) + GRU_CCH_BASE + (n) * GRU_HANDLE_STRIDE))
> +#define GRU_GSH(b)		((struct gru_global_status_handle *)	\
> +		((unsigned long)(b) + GRU_GSH_BASE))

Is there any particular reason why these had to be implemented via macros?

> +/*
> + * Test if an offset is a valid kernel handle address.
> + * 	Ex:  TYPE_IS(CBE, chiplet_offset)
> + */
> +#define TYPE_IS(hn, h)		((h) >= GRU_##hn##_BASE && (h) < 	\
> +	GRU_##hn##_BASE + GRU_NUM_##hn * GRU_HANDLE_STRIDE && 		\
> +				 (((h) & (GRU_HANDLE_STRIDE - 1)) == 0))

That one will misbehave if passed an `h' whcih hasside-effects.  I
guess that's hard to fix if you need to retain the pasting thing.

> +/*
> + * Test a GRU physical address to determine the type of address range (does
> + * NOT validate holes)
> + */
> +#define IS_MCS_PADDR(h)		(((h) & (GRU_SIZE - 1)) >= GRU_MCS_BASE)
> +#define IS_CBR_PADDR(h)		(((h) & (GRU_SIZE - 1)) < 		\
> +		GRU_MCS_BASE && (((h) & (GRU_GSEG_STRIDE - 1)) < GRU_DS_BASE))

has the same bug, but doesn't do pasting.

> +#define IS_DSR_PADDR(h)		(((h) & (GRU_SIZE - 1)) < GRU_MCS_BASE && \
> +		(((h) & (GRU_GSEG_STRIDE - 1)) >= GRU_DS_BASE))

ditto.

> +/* Convert an arbitrary handle address to the beginning of the GRU segment */
> +#ifndef __PLUGIN__
> +#define GRUBASE(h)		((void *)((unsigned long)(h) & ~(GRU_SIZE - 1)))
> +#else
> +/* Emulator hack */
> +extern void *gmu_grubase(void *h);
> +#define GRUBASE(h)		gmu_grubase(h)
> +#endif
> +
> +/* Convert a GRU physical address to the chiplet offset */
> +#define GSEGPOFF(h) ((h) & (GRU_SIZE - 1))
> +
> +/* Convert a GSEG CB address to the relative CB number within the context */
> +#define CBNUM(cb) ((((unsigned long)(cb) - GRU_CB_BASE) % GRU_GSEG_PAGESIZE) / \
> +			GRU_HANDLE_STRIDE)
> +
> +/* Convert a TFH address to the relative TFH number within the GRU*/
> +#define TFHNUM(tfh) ((((unsigned long)(tfh) - GRU_TFH_BASE) % GRU_SIZE) / \
> +			GRU_HANDLE_STRIDE)
> +
> +/* Convert a CCH address to the relative context number within the GRU*/
> +#define CCHNUM(cch) ((((unsigned long)(cch) - GRU_CCH_BASE) % GRU_SIZE) / \
> +			GRU_HANDLE_STRIDE)
> +
> +/* Convert a CBE address to the relative context number within the GRU*/
> +#define CBENUM(cbe) ((((unsigned long)(cbe) - GRU_CBE_BASE) % GRU_SIZE) / \
> +			GRU_HANDLE_STRIDE)
> +
> +/* Convert a TFM address to the relative context number within the GRU*/
> +#define TFMNUM(tfm) ((((unsigned long)(tfm) - GRU_TFM_BASE) % GRU_SIZE) / \
> +			GRU_HANDLE_STRIDE)
> +
> +/* byte offset to a specific GRU chiplet. (p=pnode, c=chiplet (0 or 1)*/
> +#define GRUCHIPOFFSET(p, c) (GRU_SIZE * ((p) * 2 + (c)))

etc.

> +#ifndef BITS_TO_LONGS
> +#define BITS_TO_LONGS(bits)     (((bits)+64-1)/64)
> +#endif

BITS_TO_LONGS is defined in include/linux/bitops.h.  Is this here just
for userspace inclusion?  If not, it can go.  If so, don't we have a
32-bit problem?  Or does this code have the suitable 64-bit Kconfig
dependencies?


> +/*
> + * GSH - GRU Status Handle
> + *	Shows status of each CBR/CBR resources
> + */
> +struct gru_global_status_handle {
> +	unsigned long bits[BITS_TO_LONGS(GRU_NUM_CBE) * 2];

That's an open-coded DECLARE_BITMAP.

I'm assuming that we're about to see large amounts of code which
reimplements the functions which the bitmap library offers, so I'll
just ask: should this code be using the bitmap library?

> +	unsigned int opc:1;
> +	unsigned int fill1:5;
> +
> +	unsigned int fill2:8;
> +
>
> ...
>
> +#ifdef __KERNEL__
> +#include "gru_instructions.h"
> +
> +/* Extract the status field from a kernel handle */
> +#define GET_MSEG_HANDLE_STATUS(h)	(((*(unsigned long *)(h)) >> 16) & 3)
> +

> +#if defined __ia64__
> +#elif defined __x86_64__
> +#endif

CONFIG_IA64 and CONFIG_X86_64 would be more fashionable.

> +static inline void start_instruction(void *h)
> +static inline int wait_instruction_complete(void *h)
> +static inline void cch_allocate_set_asids(
> +static inline void cch_allocate_set_asids(
> +static inline int cch_allocate(struct gru_context_configuration_handle *cch,
> +static inline int cch_start(struct gru_context_configuration_handle *cch)
> +static inline int cch_interrupt(struct gru_context_configuration_handle *cch)
> +static inline int cch_deallocate(struct gru_context_configuration_handle *cch)
> +static inline int cch_interrupt_sync(struct gru_context_configuration_handle
> +static inline int tgh_invalidate(struct gru_tlb_global_handle *tgh,
> +static inline void tfh_write_only(struct gru_tlb_fault_handle *tfh,
> +static inline void tfh_write_restart(struct gru_tlb_fault_handle *tfh,
> +static inline void tfh_restart(struct gru_tlb_fault_handle *tfh)
> +static inline void tfh_user_polling_mode(struct gru_tlb_fault_handle *tfh)
> +static inline void tfh_exception(struct gru_tlb_fault_handle *tfh)

wow.  Most of these are way too large to be inlined.  And inlining is
so unweildy and namespace-polluty.  How come?