Re: [PATCH] tee: amdtee: add support for use of cma region

[Devaraj Rangasamy <Devaraj.Rangasamy@xxxxxxx>]

On 8/19/2023 4:03 PM, Alexey Kardashevskiy wrote:
> On 19/8/23 00:42, Devaraj Rangasamy wrote:
> > In systems with low memory configuration, memory gets fragmented
> > easily, and any bigger size contiguous memory allocations are likely
> > to fail.
> > Contiguous Memory Allocator (CMA) is used to overcome this
> > limitation, and to guarantee memory allocations.
> >
> > This patch adds support for CMA area exclusive to amdtee.
> > The support can be enabled if kernel have CONFIG_CMA enabled.
> > The size can be set via the AMDTEE_CMA_SIZE config option
> > at compile time or with the "amdtee_cma" kernel parameter.
> > (e.g. "amdtee_cma=32 for 32MB").
> >
> > Also, cma zone is utilized only for buffer allocation bigger than
> > 64k bytes. When such allocation fails, there is a fallback to the
> > buddy allocator. Since CMA requires a boot time initialization,
> > it is enabled only when amdtee is built as an inbuilt driver.
> >
> > Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@xxxxxxx>
> > Co-developed-by: SivaSangeetha SK <SivaSangeetha.SK@xxxxxxx>
> > Signed-off-by: SivaSangeetha SK <SivaSangeetha.SK@xxxxxxx>
> > Reviewed-by: Rijo Thomas <Rijo-john.Thomas@xxxxxxx>
> > ---
> >   .../admin-guide/kernel-parameters.txt         |  7 ++
> >   arch/x86/include/asm/setup.h                  |  6 ++
> >   arch/x86/kernel/setup.c                       |  2 +
> >   drivers/tee/amdtee/Kconfig                    |  9 +++
> >   drivers/tee/amdtee/Makefile                   |  1 +
> >   drivers/tee/amdtee/amdtee_private.h           |  6 +-
> >   drivers/tee/amdtee/core.c                     |  6 +-
> >   drivers/tee/amdtee/shm_pool.c                 | 32 ++++++--
> >   drivers/tee/amdtee/shm_pool_cma.c             | 78 +++++++++++++++++++
> >   drivers/tee/amdtee/shm_pool_cma.h             | 38 +++++++++
> >   10 files changed, 176 insertions(+), 9 deletions(-)
> >   create mode 100644 drivers/tee/amdtee/shm_pool_cma.c
> >   create mode 100644 drivers/tee/amdtee/shm_pool_cma.h
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt 
> > b/Documentation/admin-guide/kernel-parameters.txt
> > index 722b6eca2e93..5e38423f3d53 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -363,6 +363,13 @@
> >                 selects a performance level in this range and 
> > appropriate
> >                 to the current workload.
> >   +    amdtee_cma=nn    [HW,TEE]
> > +            Sets the memory size reserved for contiguous memory
> > +            allocations, to be used by amdtee device driver.
> > +            Value is in MB and can range from 4 to 128 (MBs)
> > +            CMA will be active only when CMA is enabled, and amdtee is
> > +            built as inbuilt driver, and not loaded as module.
> > +
> >       amijoy.map=    [HW,JOY] Amiga joystick support
> >               Map of devices attached to JOY0DAT and JOY1DAT
> >               Format: <a>,<b>
> > diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
> > index f3495623ac99..bb5e4b7134a2 100644
> > --- a/arch/x86/include/asm/setup.h
> > +++ b/arch/x86/include/asm/setup.h
> > @@ -66,6 +66,12 @@ extern void x86_ce4100_early_setup(void);
> >   static inline void x86_ce4100_early_setup(void) { }
> >   #endif
> >   +#if IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA)
> > +void amdtee_cma_reserve(void);
> > +#else
> > +static inline void amdtee_cma_reserve(void) { }
> > +#endif
> > +
> >   #ifndef _SETUP
> >     #include <asm/espfix.h>
> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> > index fd975a4a5200..e73433af3bfa 100644
> > --- a/arch/x86/kernel/setup.c
> > +++ b/arch/x86/kernel/setup.c
> > @@ -1223,6 +1223,8 @@ void __init setup_arch(char **cmdline_p)
> >       initmem_init();
> >       dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
> >   +    amdtee_cma_reserve();
> > +
> >       if (boot_cpu_has(X86_FEATURE_GBPAGES))
> >           hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
> >   diff --git a/drivers/tee/amdtee/Kconfig b/drivers/tee/amdtee/Kconfig
> > index 191f9715fa9a..5843c739a7b8 100644
> > --- a/drivers/tee/amdtee/Kconfig
> > +++ b/drivers/tee/amdtee/Kconfig
> > @@ -6,3 +6,12 @@ config AMDTEE
> >       depends on CRYPTO_DEV_SP_PSP && CRYPTO_DEV_CCP_DD
> >       help
> >         This implements AMD's Trusted Execution Environment (TEE) 
> > driver.
> > +
> > +config AMDTEE_CMA_SIZE
> > +    int "Size of Memory in MiB reserved in CMA for AMD-TEE"
> > +    default "0"
> > +    depends on CMA && (AMDTEE=y)
> > +    help
> > +      Specify the default amount of memory in MiB reserved in CMA 
> > for AMD-TEE driver
> > +      Any amdtee shm buffer allocation larger than 64k will allocate 
> > memory from the CMA
> > +      The default can be overridden with the kernel commandline 
> > parameter "amdtee_cma".
> > \ No newline at end of file
> > diff --git a/drivers/tee/amdtee/Makefile b/drivers/tee/amdtee/Makefile
> > index ff1485266117..a197839cfcf3 100644
> > --- a/drivers/tee/amdtee/Makefile
> > +++ b/drivers/tee/amdtee/Makefile
> > @@ -3,3 +3,4 @@ obj-$(CONFIG_AMDTEE) += amdtee.o
> >   amdtee-objs += core.o
> >   amdtee-objs += call.o
> >   amdtee-objs += shm_pool.o
> > +amdtee-objs += shm_pool_cma.o
> > diff --git a/drivers/tee/amdtee/amdtee_private.h 
> > b/drivers/tee/amdtee/amdtee_private.h
> > index 6d0f7062bb87..9ba47795adb6 100644
> > --- a/drivers/tee/amdtee/amdtee_private.h
> > +++ b/drivers/tee/amdtee/amdtee_private.h
> > @@ -87,11 +87,13 @@ struct shmem_desc {
> >    * struct amdtee_shm_data - Shared memory data
> >    * @kaddr:    Kernel virtual address of shared memory
> >    * @buf_id:    Buffer id of memory mapped by TEE_CMD_ID_MAP_SHARED_MEM
> > + * @is_cma:    Indicates whether memory is allocated from cma region 
> > or not
> >    */
> >   struct amdtee_shm_data {
> >       struct  list_head shm_node;
> >       void    *kaddr;
> >       u32     buf_id;
> > +    bool    is_cma;
> >   };
> >     /**
> > @@ -145,9 +147,9 @@ int amdtee_invoke_func(struct tee_context *ctx,
> >     int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 
> > session);
> >   -int amdtee_map_shmem(struct tee_shm *shm);
> > +int amdtee_map_shmem(struct tee_shm *shm, bool is_cma);
> >   -void amdtee_unmap_shmem(struct tee_shm *shm);
> > +void amdtee_unmap_shmem(struct tee_shm *shm, bool *is_cma);
> >     int handle_load_ta(void *data, u32 size,
> >              struct tee_ioctl_open_session_arg *arg);
> > diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
> > index 372d64756ed6..448802dccf13 100644
> > --- a/drivers/tee/amdtee/core.c
> > +++ b/drivers/tee/amdtee/core.c
> > @@ -336,7 +336,7 @@ int amdtee_close_session(struct tee_context *ctx, 
> > u32 session)
> >       return 0;
> >   }
> >   -int amdtee_map_shmem(struct tee_shm *shm)
> > +int amdtee_map_shmem(struct tee_shm *shm, bool is_cma)
> >   {
> >       struct amdtee_context_data *ctxdata;
> >       struct amdtee_shm_data *shmnode;
> > @@ -368,6 +368,7 @@ int amdtee_map_shmem(struct tee_shm *shm)
> >         shmnode->kaddr = shm->kaddr;
> >       shmnode->buf_id = buf_id;
> > +    shmnode->is_cma = is_cma;
> >       ctxdata = shm->ctx->data;
> >       mutex_lock(&ctxdata->shm_mutex);
> >       list_add(&shmnode->shm_node, &ctxdata->shm_list);
> > @@ -378,7 +379,7 @@ int amdtee_map_shmem(struct tee_shm *shm)
> >       return 0;
> >   }
> >   -void amdtee_unmap_shmem(struct tee_shm *shm)
> > +void amdtee_unmap_shmem(struct tee_shm *shm, bool *is_cma)
> >   {
> >       struct amdtee_context_data *ctxdata;
> >       struct amdtee_shm_data *shmnode;
> > @@ -395,6 +396,7 @@ void amdtee_unmap_shmem(struct tee_shm *shm)
> >       mutex_lock(&ctxdata->shm_mutex);
> >       list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
> >           if (buf_id == shmnode->buf_id) {
> > +            *is_cma = shmnode->is_cma;
> >               list_del(&shmnode->shm_node);
> >               kfree(shmnode);
> >               break;
> > diff --git a/drivers/tee/amdtee/shm_pool.c 
> > b/drivers/tee/amdtee/shm_pool.c
> > index f0303126f199..9aad401387be 100644
> > --- a/drivers/tee/amdtee/shm_pool.c
> > +++ b/drivers/tee/amdtee/shm_pool.c
> > @@ -7,19 +7,30 @@
> >   #include <linux/tee_drv.h>
> >   #include <linux/psp.h>
> >   #include "amdtee_private.h"
> > +#include "shm_pool_cma.h"
> >     static int pool_op_alloc(struct tee_shm_pool *pool, struct 
> > tee_shm *shm,
> >                size_t size, size_t align)
> >   {
> >       unsigned int order = get_order(size);
> >       unsigned long va;
> > +    bool is_cma = false;
> >       int rc;
> >         /*
> >        * Ignore alignment since this is already going to be page aligned
> >        * and there's no need for any larger alignment.
> >        */
> > -    va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
> > +
> > +    /* if CMA is available, use it for higher order allocation */
> > +    if (amdtee_get_cma_size() && order > 6)
> > +        va = amdtee_alloc_from_cma(shm, order);
> > +
> > +    if (va)
> > +        is_cma = true;
> > +    else
> > +        va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
> > +
> >       if (!va)
> >           return -ENOMEM;
> >   @@ -28,9 +39,13 @@ static int pool_op_alloc(struct tee_shm_pool 
> > *pool, struct tee_shm *shm,
> >       shm->size = PAGE_SIZE << order;
> >         /* Map the allocated memory in to TEE */
> > -    rc = amdtee_map_shmem(shm);
> > +    rc = amdtee_map_shmem(shm, is_cma);
> >       if (rc) {
> > -        free_pages(va, order);
> > +        if (is_cma)
> > +            amdtee_free_from_cma(shm);
> > +        else
> > +            free_pages(va, order);
> > +
> >           shm->kaddr = NULL;
> >           return rc;
> >       }
> > @@ -40,9 +55,16 @@ static int pool_op_alloc(struct tee_shm_pool 
> > *pool, struct tee_shm *shm,
> >     static void pool_op_free(struct tee_shm_pool *pool, struct 
> > tee_shm *shm)
> >   {
> > +    bool is_cma = false;
> > +
> >       /* Unmap the shared memory from TEE */
> > -    amdtee_unmap_shmem(shm);
> > -    free_pages((unsigned long)shm->kaddr, get_order(shm->size));
> > +    amdtee_unmap_shmem(shm, &is_cma);
> > +
> > +    if (is_cma)
>
> No need in is_cma here and other places.
Ack.
cma_release() do have inbuilt validation, and returns true/false as 
result for valid cma buffer release.
> > +        amdtee_free_from_cma(shm);
> > +    else
> > +        free_pages((unsigned long)shm->kaddr, get_order(shm->size));
> > +
> >       shm->kaddr = NULL;
> >   }
> >   diff --git a/drivers/tee/amdtee/shm_pool_cma.c 
> > b/drivers/tee/amdtee/shm_pool_cma.c
> > new file mode 100644
> > index 000000000000..99dda9adb1c6
> > --- /dev/null
> > +++ b/drivers/tee/amdtee/shm_pool_cma.c
> > @@ -0,0 +1,78 @@
> > +// SPDX-License-Identifier: MIT
> > +/*
> > + * Copyright 2023 Advanced Micro Devices, Inc.
> > + */
> > +
> > +#if IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA)
> > +
> > +#define pr_fmt(fmt) "%s: " fmt, __func__
> > +
> > +#include <linux/cma.h>
> > +#include <linux/mm.h>
> > +#include <linux/tee_drv.h>
> > +#include "shm_pool_cma.h"
> > +
> > +static struct cma *amdtee_cma;
> > +unsigned long amdtee_cma_size __initdata = CONFIG_AMDTEE_CMA_SIZE * 
> > SZ_1M;
> > +
> > +static int __init early_parse_amdtee_cma(char *p)
> > +{
> > +    int cmd_size;
>
> Not int but unsigned long long.
Ack.
We have reverted new exclusive cma zone.
> > +
> > +    if (!p)
> > +        return 1;
> > +
> > +    cmd_size = memparse(p, NULL);
> > +    if (cmd_size >= 4 && cmd_size <= 256)
> > +        amdtee_cma_size = cmd_size * SZ_1M;
>
> Change the doc to use 4M and 256M instead of plain 4 and 256. Or stop 
> using memparse().
>
> /me sad.
Ack.
Thanks for review.
> > +    else
> > +        pr_err("invalid amdtee_cma size: %lu\n", amdtee_cma_size);
> > +
> > +    return 0;
> > +}
> > +early_param("amdtee_cma", early_parse_amdtee_cma);
> > +
> > +void __init amdtee_cma_reserve(void)
> > +{
> > +    int ret;
> > +
> > +    ret = cma_declare_contiguous(0, amdtee_cma_size, 0, 0, 0, false, 
> > "amdtee", &amdtee_cma);
> > +    if (ret)
> > +        pr_err("Failed to reserve CMA region of size %lu\n", 
> > amdtee_cma_size);
> > +    else
> > +        pr_info("Reserved %lu bytes CMA for amdtee\n", 
> > amdtee_cma_size);
> > +}
> > +
> > +unsigned long amdtee_alloc_from_cma(struct tee_shm *shm, unsigned 
> > int order)
> > +{
> > +    struct page *page = NULL;
> > +    unsigned long va = 0;
> > +    int nr_pages = 0;
> > +
> > +    if (amdtee_cma) {
> > +        nr_pages = 1 << order;
> > +        page = cma_alloc(amdtee_cma, nr_pages, 0, false);
> > +        if (page)
> > +            va = (unsigned long)page_to_virt(page);
> > +        else
> > +            pr_debug("failed to allocate from CMA region\n");
> > +    } else {
> > +        pr_debug("CMA region is not available\n");
> > +    }
> > +    return va;
> > +}
> > +
> > +void amdtee_free_from_cma(struct tee_shm *shm)
> > +{
> > +    struct page *page;
> > +    int nr_pages = 0;
> > +
> > +    if (amdtee_cma) {
> > +        nr_pages = 1 << get_order(shm->size);
> > +        page = virt_to_page(shm->kaddr);
> > +        cma_release(amdtee_cma, page, nr_pages);
> > +    } else {
> > +        pr_err("CMA region is not available\n");
> > +    }
> > +}
> > +#endif /* IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA) */
> > diff --git a/drivers/tee/amdtee/shm_pool_cma.h 
> > b/drivers/tee/amdtee/shm_pool_cma.h
> > new file mode 100644
> > index 000000000000..d1cde11cbede
> > --- /dev/null
> > +++ b/drivers/tee/amdtee/shm_pool_cma.h
> > @@ -0,0 +1,38 @@
> > +/* SPDX-License-Identifier: MIT */
> > +
> > +/*
> > + * Copyright 2023 Advanced Micro Devices, Inc.
> > + */
> > +
> > +#ifndef SHM_POOL_CMA_H
> > +#define SHM_POOL_CMA_H
> > +
> > +#if IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA)
> > +
> > +extern unsigned long amdtee_cma_size;
> > +
> > +static inline unsigned long amdtee_get_cma_size(void)
> > +{
> > +    return amdtee_cma_size;
> > +}
> > +
> > +unsigned long amdtee_alloc_from_cma(struct tee_shm *shm, unsigned 
> > int order);
> > +
> > +void amdtee_free_from_cma(struct tee_shm *shm);
> > +
> > +#else /* IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA) */
> > +
> > +static inline unsigned long amdtee_get_cma_size(void)
> > +{
> > +    return 0;
> > +}
> > +
> > +static inline unsigned long amdtee_alloc_from_cma(struct tee_shm 
> > *shm, unsigned int order)
> > +{
> > +    return 0;
> > +}
> > +
> > +static inline void amdtee_free_from_cma(struct tee_shm *shm) { }
> > +
> > +#endif /* IS_BUILTIN(CONFIG_AMDTEE) && IS_ENABLED(CONFIG_CMA) */
> > +#endif /* SHM_POOL_CMA_H */