On 10/22/2012 04:18:07 PM, Tabi Timur-B04825 wrote:
On Wed, Oct 17, 2012 at 12:32 PM, Varun Sethi
<varun.se...@freescale.com> wrote:
> +}
> +
> +static unsigned long pamu_get_fspi_and_allocate(u32 subwin_cnt)
> +{
subwin_cnt should probably be an unsigned int.
This function needs to be documented. What value is being returned?
spaact offset (yes, this needs to be documented)
> + unsigned long spaace_addr;
> +
> + spaace_addr = gen_pool_alloc(spaace_pool, subwin_cnt *
sizeof(paace_t));
> + if (!spaace_addr)
> + return ULONG_MAX;
What's wrong with returning 0 on error?
0 is a valid spaact offset
> +
> + return (spaace_addr - (unsigned long)spaact) /
(sizeof(paace_t));
Is this supposed to be a virtual address? If so, then return void*
instead of an unsigned long.
It's not a virtual address. How often does subtraction followed by
division result in a valid virtual address?
> +int pamu_update_paace_stash(int liodn, u32 subwin, u32 value)
Whitespace
> +#define PAMU_PAGE_SHIFT 12
> +#define PAMU_PAGE_SIZE 4096ULL
4096ULL? Why not just 4096?
This lets it be used in phys_addr_t expressions without needing casts
everywhere or dropping bits.
> +/* This bitmap advertises the page sizes supported by PAMU hardware
> + * to the IOMMU API.
> + */
> +#define FSL_PAMU_PGSIZES (~0xFFFUL)
There should be a better way to define this. ~(PAMU_PAGE_SIZE-1)
maybe?
Is it even true? We don't support IOMMU pages larger than the SoC can
address.
The (~0xFFFUL) version also discards some valid IOMMU page sizes on
32-bit kernels. One use case for windows larger than the CPU virtual
address space is creating one big identity-map window to effectively
disable translation. If we're to support that, the size of
pgsize_bitmap
will need to change as well.
> +static int map_liodn(int liodn, struct fsl_dma_domain *dma_domain)
> +{
> + u32 subwin_cnt = dma_domain->subwin_cnt;
> + unsigned long rpn;
> + int ret = 0, i;
> +
> + if (subwin_cnt) {
> + struct dma_subwindow *sub_win_ptr =
> + &dma_domain->sub_win_arr[0];
> + for (i = 0; i < subwin_cnt; i++) {
> + if (sub_win_ptr[i].valid) {
> + rpn = sub_win_ptr[i].paddr >>
> + PAMU_PAGE_SHIFT,
> + spin_lock(&iommu_lock);
> + ret = pamu_config_spaace(liodn,
subwin_cnt, i,
> +
sub_win_ptr[i].size,
> + -1,
> + rpn,
> +
dma_domain->snoop_id,
> +
dma_domain->stash_id,
> + (i > 0) ?
1 : 0,
> +
sub_win_ptr[i].prot);
> + spin_unlock(&iommu_lock);
> + if (ret) {
> + pr_err("PAMU SPAACE
configuration failed for liodn %d\n",
> + liodn);
> + return ret;
> + }
> + }
> + }
Break up that nesting with some subfunctions.
> + while (!list_empty(&dma_domain->devices)) {
> + info = list_entry(dma_domain->devices.next,
> + struct device_domain_info, link);
> + remove_domain_ref(info, dma_domain->subwin_cnt);
> + }
I wonder if you should use list_for_each_safe() instead.
The above is simpler if you're destroying the entire list.
> +}
> +
> +static int configure_domain_dma_state(struct fsl_dma_domain
*dma_domain, int enable)
bool enable
Finally, please CC: me on all IOMMU and PAMU patches you post
upstream.
Me too.
-Scott
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